Remove deprecation of standalone mode (#680)

* Remove deprecation of standalone mode

* Update standalone-mode.md

.circleci/Makefile

@@ -1,16 +0,0 @@
-.PHONY: all
-all:
-
-.PHONY: install-test-deps
-install-test-deps:
-	go get -v github.com/int128/goxzst
-
-.PHONY: install-release-deps
-install-release-deps: go
-	go get -v github.com/int128/goxzst github.com/int128/ghcp
-
-go:
-	curl -sSfL -o go.tgz "https://golang.org/dl/go`ruby go_version_from_config.rb < config.yml`.darwin-amd64.tar.gz"
-	tar -xf go.tgz
-	rm go.tgz
-	./go/bin/go version

.circleci/config.yml

@@ -1,60 +0,0 @@
-version: 2.1
-
-jobs:
-  test:
-    docker:
-      - image: cimg/go:1.15.3
-    steps:
-      - checkout
-      - restore_cache:
-          keys:
-            - go-sum-{{ checksum "go.sum" }}
-      - run: make -C .circleci install-test-deps
-      - run: mkdir -p /tmp/gotest
-      - run: gotestsum --junitfile /tmp/gotest/gotest.xml -- -v -race -cover -coverprofile=coverage.out ./...
-      - store_test_results:
-          path: /tmp/gotest
-      - save_cache:
-          key: go-sum-{{ checksum "go.sum" }}
-          paths:
-            - ~/go/pkg
-      - run: bash <(curl -s https://codecov.io/bash)
-
-  release:
-    macos:
-      # https://circleci.com/docs/2.0/testing-ios/
-      xcode: 11.5.0
-    steps:
-      - run: echo 'export PATH="$HOME/go/bin:$PWD/.circleci/go/bin:$PATH"' >> $BASH_ENV
-      - checkout
-      - restore_cache:
-          keys:
-            - go-macos-{{ checksum "go.sum" }}
-      - run: make -C .circleci install-release-deps
-      - run: make dist
-      - run: |
-          if [ "$CIRCLE_TAG" ]; then
-            make release
-          fi
-      - save_cache:
-          key: go-macos-{{ checksum "go.sum" }}
-          paths:
-            - ~/go/pkg
-
-workflows:
-  version: 2
-  build:
-    jobs:
-      - test:
-          filters:
-            tags:
-              only: /^v.*/
-      - release:
-          context: open-source
-          requires:
-            - test
-          filters:
-            branches:
-              only: /^release-feature.*/
-            tags:
-              only: /^v.*/

.circleci/go.mod

@@ -1,3 +0,0 @@
-module github.com/int128/kubelogin/.circleci
-
-go 1.13

.circleci/go_version_from_config.rb

@@ -1,11 +0,0 @@
-require 'yaml'
-
-config = YAML.load(STDIN)
-
-image = config["jobs"]["test"]["docker"][0]["image"]
-if !image.start_with?("cimg/go:")
-  raise "unknown image #{image} in #{configPath}"
-end
-
-goVersion = image.delete_prefix("cimg/go:")
-print(goVersion)

.github/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,20 @@
+---
+name: Question
+about: Feel free to ask a question
+title: ''
+labels: question
+assignees: ''
+
+---
+
+## Describe the question
+A clear and concise description of what the issue is.
+
+## To reproduce
+A console log or steps to reproduce the issue.
+
+## Your environment
+- OS: e.g. macOS
+- kubelogin version: e.g. v1.19
+- kubectl version: e.g. v1.19
+- OpenID Connect provider: e.g. Google

.github/renovate.json

@@ -1,8 +0,0 @@
-{
-  "extends": [
-    "config:base"
-  ],
-  "postUpdateOptions": [
-    "gomodTidy"
-  ]
-}

.github/renovate.json5

@@ -0,0 +1,6 @@
+{
+  "extends": [
+    "config:base",
+    "github>int128/go-actions",
+  ],
+}

.github/workflows/docker.yaml

@@ -0,0 +1,52 @@
+name: docker
+
+on:
+  pull_request:
+    branches:
+      - master
+    paths:
+      - .github/workflows/docker.yaml
+      - pkg/**
+      - go.*
+      - Dockerfile
+      - Makefile
+  push:
+    branches:
+      - master
+    paths:
+      - .github/workflows/docker.yaml
+      - pkg/**
+      - go.*
+      - Dockerfile
+      - Makefile
+    tags:
+      - v*
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: docker/metadata-action@v3
+        id: metadata
+        with:
+          images: ghcr.io/${{ github.repository }}
+      - uses: int128/docker-build-cache-config-action@v1
+        id: cache
+        with:
+          image: ghcr.io/${{ github.repository }}/cache
+      - uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - uses: docker/setup-qemu-action@v1
+      - uses: docker/setup-buildx-action@v1
+      - uses: docker/build-push-action@v2
+        with:
+          push: ${{ github.event_name == 'push' }}
+          tags: ${{ steps.metadata.outputs.tags }}
+          labels: ${{ steps.metadata.outputs.labels }}
+          cache-from: ${{ steps.cache.outputs.cache-from }}
+          cache-to: ${{ steps.cache.outputs.cache-to }}
+          platforms: linux/amd64,linux/arm64

.github/workflows/go.yaml

@@ -0,0 +1,45 @@
+name: go
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - .github/workflows/go.yaml
+      - pkg/**
+      - go.*
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - master
+    paths:
+      - .github/workflows/go.yaml
+      - pkg/**
+      - go.*
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v2
+      - uses: int128/go-actions/setup@v1
+        with:
+          go-version: 1.16
+      - uses: golangci/golangci-lint-action@v2
+        with:
+          version: v1.43.0
+          skip-go-installation: true
+          skip-pkg-cache: true
+          skip-build-cache: true
+
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v2
+      - uses: int128/go-actions/setup@v1
+        with:
+          go-version: 1.16
+      - run: go test -v -race ./...

.github/workflows/golangci-lint.yaml

@@ -1,14 +0,0 @@
-on:
-  pull_request:
-    paths:
-      - .github/workflows/golangci-lint.yaml
-      - '**.go'
-jobs:
-  golangci:
-    name: lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: golangci/golangci-lint-action@v2
-        with:
-          version: v1.30

.github/workflows/release.yaml

@@ -0,0 +1,70 @@
+name: release
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - .github/workflows/release.yaml
+      - pkg/**
+      - go.*
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - master
+    paths:
+      - .github/workflows/release.yaml
+      - pkg/**
+      - go.*
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        platform:
+          - runs-on: ubuntu-latest
+            GOOS: linux
+            GOARCH: amd64
+            CGO_ENABLED: 0 # https://github.com/int128/kubelogin/issues/567
+          - runs-on: ubuntu-latest
+            GOOS: linux
+            GOARCH: arm64
+          - runs-on: ubuntu-latest
+            GOOS: linux
+            GOARCH: arm
+          - runs-on: macos-latest
+            GOOS: darwin
+            GOARCH: amd64
+            CGO_ENABLED: 1 # https://github.com/int128/kubelogin/issues/249
+          - runs-on: macos-latest
+            GOOS: darwin
+            GOARCH: arm64
+          - runs-on: windows-latest
+            GOOS: windows
+            GOARCH: amd64
+    runs-on: ${{ matrix.platform.runs-on }}
+    env:
+      GOOS: ${{ matrix.platform.GOOS }}
+      GOARCH: ${{ matrix.platform.GOARCH }}
+      CGO_ENABLED: ${{ matrix.platform.CGO_ENABLED }}
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v2
+      - uses: int128/go-actions/setup@v1
+        with:
+          go-version: 1.16
+      - run: go build -ldflags "-X main.version=${GITHUB_REF##*/}"
+      - uses: int128/go-actions/release@v1
+        with:
+          binary: kubelogin
+
+  publish:
+    if: startswith(github.ref, 'refs/tags/')
+    needs:
+      - build
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v2
+      - uses: rajatjindal/krew-release-bot@v0.0.40

.github/workflows/system-test.yaml

@@ -1,14 +1,23 @@
+name: system-test
+
 on:
   pull_request:
-    paths: 
+    branches:
+      - master
+    paths:
       - .github/workflows/system-test.yaml
       - system_test/**
       - pkg/**
       - go.*
   push:
-    # for go mod tidy
-    branches: [master]
-    paths: [go.*]
+    branches:
+      - master
+    paths:
+      - .github/workflows/system-test.yaml
+      - system_test/**
+      - pkg/**
+      - go.*
+
 jobs:
   system-test:
     # https://help.github.com/en/actions/automating-your-workflow-with-github-actions/software-installed-on-github-hosted-runners#ubuntu-1804-lts
@@ -16,7 +25,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.16
         id: go
       - uses: actions/checkout@v2
       - uses: actions/cache@v2

.gitignore

@@ -2,10 +2,9 @@
 
 /acceptance_test/output/
 
-/dist/output
 /coverage.out
 
 /kubelogin
 /kubectl-oidc_login
-
-/.circleci/go/
+/kubelogin_*.zip
+/kubelogin_*.zip.sha256

.krew.yaml

@@ -0,0 +1,62 @@
+apiVersion: krew.googlecontainertools.github.com/v1alpha2
+kind: Plugin
+metadata:
+  name: oidc-login
+spec:
+  homepage: https://github.com/int128/kubelogin
+  shortDescription: Log in to the OpenID Connect provider
+  description: |
+    This is a kubectl plugin for Kubernetes OpenID Connect (OIDC) authentication.
+
+    ## Credential plugin mode
+    kubectl executes oidc-login before calling the Kubernetes APIs.
+    oidc-login automatically opens the browser and you can log in to the provider.
+    After authentication, kubectl gets the token from oidc-login and you can access the cluster.
+    See https://github.com/int128/kubelogin#credential-plugin-mode for more.
+
+    ## Standalone mode
+    Run `kubectl oidc-login`.
+    It automatically opens the browser and you can log in to the provider.
+    After authentication, it writes the token to the kubeconfig and you can access the cluster.
+    See https://github.com/int128/kubelogin#standalone-mode for more.
+
+  caveats: |
+    You need to setup the OIDC provider, Kubernetes API server, role binding and kubeconfig.
+  version: {{ .TagName }}
+  platforms:
+  - bin: kubelogin
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_linux_amd64.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: linux
+        arch: amd64
+  - bin: kubelogin
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_linux_arm64.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: linux
+        arch: arm64
+  - bin: kubelogin
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_linux_arm.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: linux
+        arch: arm
+  - bin: kubelogin
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_darwin_amd64.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: darwin
+        arch: amd64
+  - bin: kubelogin
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_darwin_arm64.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: darwin
+        arch: arm64
+  - bin: kubelogin.exe
+    {{ addURIAndSha "https://github.com/int128/kubelogin/releases/download/{{ .TagName }}/kubelogin_windows_amd64.zip" .TagName }}
+    selector:
+      matchLabels:
+        os: windows
+        arch: amd64

Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:1.17 as builder
+
+WORKDIR /builder
+COPY go.* .
+RUN go mod download
+COPY main.go .
+COPY pkg pkg
+RUN go build
+
+FROM gcr.io/distroless/base-debian10
+COPY --from=builder /builder/kubelogin /
+ENTRYPOINT ["/kubelogin"]

Makefile

@@ -1,44 +0,0 @@
-# CircleCI specific variables
-CIRCLE_TAG ?= latest
-GITHUB_USERNAME := $(CIRCLE_PROJECT_USERNAME)
-GITHUB_REPONAME := $(CIRCLE_PROJECT_REPONAME)
-
-TARGET := kubelogin
-TARGET_OSARCH := linux_amd64 darwin_amd64 windows_amd64 linux_arm linux_arm64
-VERSION ?= $(CIRCLE_TAG)
-LDFLAGS := -X main.version=$(VERSION)
-
-all: $(TARGET)
-
-$(TARGET): $(wildcard **/*.go)
-	go build -o $@ -ldflags "$(LDFLAGS)"
-
-.PHONY: dist
-dist: dist/output
-dist/output:
-	# make the zip files for GitHub Releases
-	VERSION=$(VERSION) goxzst -d dist/output -i "LICENSE" -o "$(TARGET)" -osarch "$(TARGET_OSARCH)" -t "dist/kubelogin.rb dist/oidc-login.yaml dist/Dockerfile" -- -ldflags "$(LDFLAGS)"
-	# test the zip file
-	zipinfo dist/output/kubelogin_linux_amd64.zip
-	# make the krew yaml structure
-	mkdir -p dist/output/plugins
-	mv dist/output/oidc-login.yaml dist/output/plugins/oidc-login.yaml
-
-.PHONY: release
-release: dist
-	# publish the binaries
-	ghcp release -u "$(GITHUB_USERNAME)" -r "$(GITHUB_REPONAME)" -t "$(VERSION)" dist/output/
-	# publish the Homebrew formula
-	ghcp commit -u "$(GITHUB_USERNAME)" -r "homebrew-$(GITHUB_REPONAME)" -b "bump-$(VERSION)" -m "Bump the version to $(VERSION)" -C dist/output/ kubelogin.rb
-	ghcp pull-request -u "$(GITHUB_USERNAME)" -r "homebrew-$(GITHUB_REPONAME)" -b "bump-$(VERSION)" --title "Bump the version to $(VERSION)"
-	# publish the Dockerfile
-	ghcp commit -u "$(GITHUB_USERNAME)" -r "$(GITHUB_REPONAME)-docker" -b "bump-$(VERSION)" -m "Bump the version to $(VERSION)" -C dist/output/ Dockerfile
-	ghcp pull-request -u "$(GITHUB_USERNAME)" -r "$(GITHUB_REPONAME)-docker" -b "bump-$(VERSION)" --title "Bump the version to $(VERSION)"
-	# publish the Krew manifest
-	ghcp fork-commit -u kubernetes-sigs -r krew-index -b "oidc-login-$(VERSION)" -m "Bump oidc-login to $(VERSION)" -C dist/output/ plugins/oidc-login.yaml
-
-.PHONY: clean
-clean:
-	-rm $(TARGET)
-	-rm -r dist/output/
-	-rm coverage.out gotest.log

README.md

@@ -1,4 +1,4 @@
-# kubelogin [![CircleCI](https://circleci.com/gh/int128/kubelogin.svg?style=shield)](https://circleci.com/gh/int128/kubelogin) [![Go Report Card](https://goreportcard.com/badge/github.com/int128/kubelogin)](https://goreportcard.com/report/github.com/int128/kubelogin)
+# kubelogin [![go](https://github.com/int128/kubelogin/actions/workflows/go.yaml/badge.svg)](https://github.com/int128/kubelogin/actions/workflows/go.yaml) [![Go Report Card](https://goreportcard.com/badge/github.com/int128/kubelogin)](https://goreportcard.com/report/github.com/int128/kubelogin)
 
 This is a kubectl plugin for [Kubernetes OpenID Connect (OIDC) authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens), also known as `kubectl oidc-login`.
 
@@ -31,6 +31,8 @@ kubectl krew install oidc-login
 choco install kubelogin
 ```
 
+If you install via GitHub releases, you need to put the `kubelogin` binary on your path under the name `kubectl-oidc_login` so that the [kubectl plugin mechanism](https://kubernetes.io/docs/tasks/extend-kubectl/kubectl-plugins/) can find it when you invoke `kubectl oidc-login`. The other install methods do this for you.
+
 You need to set up the OIDC provider, cluster role binding, Kubernetes API server and kubeconfig.
 The kubeconfig looks like:
 
@@ -65,7 +67,7 @@ Kubelogin automatically opens the browser, and you can log in to the provider.
 
 <img src="docs/keycloak-login.png" alt="keycloak-login" width="455" height="329">
 
-After authentication, kubelogin returns the credentials to kubectl and finally kubectl calls the Kubernetes APIs with the credential.
+After authentication, kubelogin returns the credentials to kubectl and kubectl then calls the Kubernetes APIs with these credentials.
 
 ```
 % kubectl get pods
@@ -78,13 +80,13 @@ Kubelogin writes the ID token and refresh token to the token cache file.
 
 If the cached ID token is valid, kubelogin just returns it.
 If the cached ID token has expired, kubelogin will refresh the token using the refresh token.
-If the refresh token has expired, kubelogin will perform reauthentication.
+If the refresh token has expired, kubelogin will perform re-authentication (you will have to login via browser again).
 
 
 ### Troubleshoot
 
 You can log out by removing the token cache directory (default `~/.kube/cache/oidc-login`).
-Kubelogin will perform authentication if the token cache file does not exist.
+Kubelogin will ask you to login via browser again if the token cache file does not exist i.e., it starts with a clean slate
 
 You can dump claims of an ID token by `setup` command.
 
@@ -123,7 +125,7 @@ You can verify kubelogin works with your provider using [acceptance test](accept
 
 - [Setup guide](docs/setup.md)
 - [Usage and options](docs/usage.md)
-- [Standalone mode](docs/standalone-mode.md) (deprecated)
+- [Standalone mode](docs/standalone-mode.md)
 
 
 ## Related works
@@ -142,7 +144,7 @@ Your pull request will be merged into master with squash.
 
 ### Development
 
-Go 1.15+ is required.
+Go 1.16+ is required.
 
 ```sh
 make

dist/Dockerfile

@@ -1,13 +0,0 @@
-FROM alpine:3.12
-
-ARG KUBELOGIN_VERSION="{{ env "VERSION" }}"
-ARG KUBELOGIN_SHA256="{{ sha256 .linux_amd64_archive }}"
-
-# Download the release and test the checksum
-RUN wget -O /kubelogin.zip "https://github.com/int128/kubelogin/releases/download/$KUBELOGIN_VERSION/kubelogin_linux_amd64.zip" && \
-    echo "$KUBELOGIN_SHA256  /kubelogin.zip" | sha256sum -c - && \
-    unzip /kubelogin.zip && \
-    rm /kubelogin.zip
-
-USER daemon
-ENTRYPOINT ["/kubelogin"]

dist/kubelogin.rb

@@ -1,27 +0,0 @@
-class Kubelogin < Formula
-  desc "A kubectl plugin for Kubernetes OpenID Connect authentication"
-  homepage "https://github.com/int128/kubelogin"
-  baseurl = "https://github.com/int128/kubelogin/releases/download"
-  version "{{ env "VERSION" }}"
-  
-  if OS.mac?
-    kernel = "darwin"
-    sha256 "{{ sha256 .darwin_amd64_archive }}"
-  elsif OS.linux?
-    kernel = "linux"
-    sha256 "{{ sha256 .linux_amd64_archive }}"
-  end 
-   
-  url baseurl + "/#{version}/kubelogin_#{kernel}_amd64.zip"
-    
-  def install
-    bin.install "kubelogin" => "kubelogin"
-    ln_s bin/"kubelogin", bin/"kubectl-oidc_login"
-  end
-  
-  test do
-    system "#{bin}/kubelogin -h"
-    system "#{bin}/kubectl-oidc_login -h"
-  end
-    
-end

dist/oidc-login.yaml

@@ -1,86 +0,0 @@
-apiVersion: krew.googlecontainertools.github.com/v1alpha2
-kind: Plugin
-metadata:
-  name: oidc-login
-spec:
-  homepage: https://github.com/int128/kubelogin
-  shortDescription: Log in to the OpenID Connect provider
-  description: |
-    This is a kubectl plugin for Kubernetes OpenID Connect (OIDC) authentication.
-
-    ## Credential plugin mode
-    kubectl executes oidc-login before calling the Kubernetes APIs.
-    oidc-login automatically opens the browser and you can log in to the provider.
-    After authentication, kubectl gets the token from oidc-login and you can access the cluster.
-    See https://github.com/int128/kubelogin#credential-plugin-mode for more.
-
-    ## Standalone mode
-    Run `kubectl oidc-login`.
-    It automatically opens the browser and you can log in to the provider.
-    After authentication, it writes the token to the kubeconfig and you can access the cluster.
-    See https://github.com/int128/kubelogin#standalone-mode for more.
-
-  caveats: |
-    You need to setup the OIDC provider, Kubernetes API server, role binding and kubeconfig.
-  version: {{ env "VERSION" }}
-  platforms:
-    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_linux_amd64.zip
-      sha256: "{{ sha256 .linux_amd64_archive }}"
-      bin: kubelogin
-      files:
-        - from: kubelogin
-          to: .
-        - from: LICENSE
-          to: .
-      selector:
-        matchLabels:
-          os: linux
-          arch: amd64
-    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_darwin_amd64.zip
-      sha256: "{{ sha256 .darwin_amd64_archive }}"
-      bin: kubelogin
-      files:
-        - from: kubelogin
-          to: .
-        - from: LICENSE
-          to: .
-      selector:
-        matchLabels:
-          os: darwin
-          arch: amd64
-    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_windows_amd64.zip
-      sha256: "{{ sha256 .windows_amd64_archive }}"
-      bin: kubelogin.exe
-      files:
-        - from: kubelogin.exe
-          to: .
-        - from: LICENSE
-          to: .
-      selector:
-        matchLabels:
-          os: windows
-          arch: amd64
-    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_linux_arm.zip
-      sha256: "{{ sha256 .linux_arm_archive }}"
-      bin: kubelogin
-      files:
-        - from: kubelogin
-          to: .
-        - from: LICENSE
-          to: .
-      selector:
-        matchLabels:
-          os: linux
-          arch: arm
-    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_linux_arm64.zip
-      sha256: "{{ sha256 .linux_arm64_archive }}"
-      bin: kubelogin
-      files:
-        - from: kubelogin
-          to: .
-        - from: LICENSE
-          to: .
-      selector:
-        matchLabels:
-          os: linux
-          arch: arm64

docs/setup.md

@@ -129,6 +129,25 @@ You do not need to set `YOUR_CLIENT_SECRET`.
 If you need `groups` claim for access control,
 see [jetstack/okta-kubectl-auth](https://github.com/jetstack/okta-kubectl-auth/blob/master/docs/okta-setup.md) and [#250](https://github.com/int128/kubelogin/issues/250).
 
+### Ping Identity
+
+Login with an account that has permissions to create applications.
+Create an OIDC application with the following configuration:
+
+- Redirect URIs:
+    - `http://localhost:8000`
+    - `http://localhost:18000` (used if the port 8000 is already in use)
+- Grant type: Authorization Code
+- PKCE Enforcement: Required
+
+Leverage the following variables in the next steps.
+
+Variable                | Value
+------------------------|------
+`ISSUER_URL`            | `https://auth.pingone.com/<PingOne Tenant Id>/as`
+`YOUR_CLIENT_ID`        |  random string
+
+`YOUR_CLIENT_SECRET` is not required for this configuration.
 
 ## 2. Verify authentication
 

docs/standalone-mode.md

@@ -1,9 +1,12 @@
 # Standalone mode
 
-You can run kubelogin as a standalone command.
-In this mode, you need to manually run the command before running kubectl.
+Kubelogin supports the standalone mode as well.
+It writes the token to the kubeconfig (typically `~/.kube/config`) after authentication.
 
-Configure the kubeconfig like:
+
+## Getting started
+
+Configure your kubeconfig like:
 
 ```yaml
 - name: keycloak
@@ -31,7 +34,7 @@ It automatically opens the browser and you can log in to the provider.
 
 After authentication, kubelogin writes the ID token and refresh token to the kubeconfig.
 
-```
+```console
 % kubelogin
 Open http://localhost:8000 for authentication
 You got a valid token until 2019-05-18 10:28:51 +0900 JST
@@ -40,7 +43,7 @@ Updated ~/.kubeconfig
 
 Now you can access the cluster.
 
-```
+```console
 % kubectl get pods
 NAME                          READY   STATUS    RESTARTS   AGE
 echoserver-86c78fdccd-nzmd5   1/1     Running   0          26d
@@ -64,7 +67,7 @@ users:
 
 If the ID token is valid, kubelogin does nothing.
 
-```
+```console
 % kubelogin
 You already have a valid token until 2019-05-18 10:28:51 +0900 JST
 ```
@@ -75,8 +78,6 @@ If the refresh token has expired, kubelogin will proceed the authentication.
 
 ## Usage
 
-### Kubeconfig
-
 You can set path to the kubeconfig file by the option or the environment variable just like kubectl.
 It defaults to `~/.kube/config`.
 
@@ -104,26 +105,4 @@ Key | Direction | Value
 `id-token`                        | Write | ID token got from the provider.
 `refresh-token`                   | Write | Refresh token got from the provider.
 
-### Extra scopes
-
-You can set the extra scopes to request to the provider by `extra-scopes` in the kubeconfig.
-
-```sh
-kubectl config set-credentials keycloak --auth-provider-arg extra-scopes=email
-```
-
-Currently kubectl does not accept multiple scopes, so you need to edit the kubeconfig as like:
-
-```sh
-kubectl config set-credentials keycloak --auth-provider-arg extra-scopes=SCOPES
-sed -i '' -e s/SCOPES/email,profile/ $KUBECONFIG
-```
-
-### CA Certificates
-
-You can use your self-signed certificates for the provider.
-
-```sh
-kubectl config set-credentials keycloak \
-  --auth-provider-arg idp-certificate-authority=$HOME/.kube/keycloak-ca.pem
-```
+See also [usage.md](usage.md).

docs/usage.md

@@ -11,6 +11,7 @@ Flags:
       --oidc-client-id string                           Client ID of the provider (mandatory)
       --oidc-client-secret string                       Client secret of the provider
       --oidc-extra-scope strings                        Scopes to request to the provider
+      --oidc-use-pkce                                   Force PKCE usage
       --token-cache-dir string                          Path to a directory for token cache (default "~/.kube/cache/oidc-login")
       --certificate-authority stringArray               Path to a cert file for the certificate authority
       --certificate-authority-data stringArray          Base64 encoded cert for the certificate authority
@@ -20,6 +21,7 @@ Flags:
       --grant-type string                               Authorization grant type to use. One of (auto|authcode|authcode-keyboard|password) (default "auto")
       --listen-address strings                          [authcode] Address to bind to the local server. If multiple addresses are set, it will try binding in order (default [127.0.0.1:8000,127.0.0.1:18000])
       --skip-open-browser                               [authcode] Do not open the browser automatically
+      --browser-command string                          [authcode] Command to open the browser
       --authentication-timeout-sec int                  [authcode] Timeout of authentication in seconds (default 180)
       --local-server-cert string                        [authcode] Certificate path for the local server
       --local-server-key string                         [authcode] Certificate key path for the local server
@@ -31,13 +33,14 @@ Flags:
   -h, --help                                            help for get-token
 
 Global Flags:
-      --add_dir_header                   If true, adds the file directory to the header
+      --add_dir_header                   If true, adds the file directory to the header of the log messages
       --alsologtostderr                  log to standard error as well as files
       --log_backtrace_at traceLocation   when logging hits line file:N, emit a stack trace (default :0)
       --log_dir string                   If non-empty, write log files in this directory
       --log_file string                  If non-empty, use this log file
       --log_file_max_size uint           Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited. (default 1800)
       --logtostderr                      log to standard error instead of files (default true)
+      --one_output                       If true, only write logs to their native severity level (vs also writing to each lower severity level)
       --skip_headers                     If true, avoid header prefixes in the log messages
       --skip_log_headers                 If true, avoid headers when opening log files
       --stderrthreshold severity         logs at or above this threshold go to stderr (default 2)
@@ -83,6 +86,16 @@ You can use your self-signed certificate for the provider.
 You can set the following environment variables if you are behind a proxy: `HTTP_PROXY`, `HTTPS_PROXY` and `NO_PROXY`.
 See also [net/http#ProxyFromEnvironment](https://golang.org/pkg/net/http/#ProxyFromEnvironment).
 
+### Home directory expansion
+
+If a value in the following options begins with a tilde character `~`, it is expanded to the home directory.
+
+- `--certificate-authority`
+- `--local-server-cert`
+- `--local-server-key`
+- `--token-cache-dir`
+
+
 ## Authentication flows
 
 Kubelogin support the following flows:
@@ -207,7 +220,7 @@ Password:
 
 ## Run in Docker
 
-You can run [the Docker image](https://quay.io/repository/int128/kubelogin) instead of the binary.
+You can run [the Docker image](https://ghcr.io/int128/kubelogin) instead of the binary.
 The kubeconfig looks like:
 
 ```yaml
@@ -224,7 +237,7 @@ users:
       - /tmp/.token-cache:/.token-cache
       - -p
       - 8000:8000
-      - quay.io/int128/kubelogin
+      - ghcr.io/int128/kubelogin
       - get-token
       - --token-cache-dir=/.token-cache
       - --listen-address=0.0.0.0:8000

go.mod

@@ -1,28 +1,25 @@
 module github.com/int128/kubelogin
 
-go 1.12
+go 1.16
 
 require (
 	github.com/alexflint/go-filemutex v1.1.0
-	github.com/chromedp/chromedp v0.5.3
-	github.com/coreos/go-oidc v2.2.1+incompatible
-	github.com/dgrijalva/jwt-go v3.2.0+incompatible
-	github.com/golang/mock v1.4.4
-	github.com/google/go-cmp v0.5.2
-	github.com/google/wire v0.4.0
-	github.com/int128/oauth2cli v1.13.0
-	github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4
-	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 // indirect
-	github.com/spf13/cobra v1.1.1
+	github.com/chromedp/chromedp v0.7.6
+	github.com/coreos/go-oidc/v3 v3.1.0
+	github.com/golang-jwt/jwt/v4 v4.2.0
+	github.com/golang/mock v1.6.0
+	github.com/google/go-cmp v0.5.6
+	github.com/google/wire v0.5.0
+	github.com/int128/oauth2cli v1.14.0
+	github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8
+	github.com/spf13/cobra v1.3.0
 	github.com/spf13/pflag v1.0.5
-	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
-	golang.org/x/net v0.0.0-20200822124328-c89045814202
-	golang.org/x/oauth2 v0.0.0-20200902213428-5d25da1a8d43
-	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208
-	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
-	gopkg.in/square/go-jose.v2 v2.3.1 // indirect
-	gopkg.in/yaml.v2 v2.3.0
-	k8s.io/apimachinery v0.19.3
-	k8s.io/client-go v0.19.3
-	k8s.io/klog v1.0.0
+	golang.org/x/net v0.0.0-20211123203042-d83791d6bcd9
+	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211
+	gopkg.in/yaml.v2 v2.4.0
+	k8s.io/apimachinery v0.22.4
+	k8s.io/client-go v0.22.4
+	k8s.io/klog/v2 v2.40.1
 )

integration_test/credetial_plugin_test.go

@@ -13,8 +13,8 @@ import (
 	"github.com/int128/kubelogin/integration_test/httpdriver"
 	"github.com/int128/kubelogin/integration_test/keypair"
 	"github.com/int128/kubelogin/integration_test/oidcserver"
-	"github.com/int128/kubelogin/pkg/adaptors/browser"
 	"github.com/int128/kubelogin/pkg/di"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser"
 	"github.com/int128/kubelogin/pkg/testing/clock"
 	"github.com/int128/kubelogin/pkg/testing/logger"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

integration_test/httpdriver/http_driver.go

@@ -60,6 +60,10 @@ func (c *client) Open(url string) error {
 	return nil
 }
 
+func (c *client) OpenCommand(_ context.Context, url, _ string) error {
+	return c.Open(url)
+}
+
 type zeroClient struct {
 	t *testing.T
 }
@@ -68,3 +72,7 @@ func (c *zeroClient) Open(url string) error {
 	c.t.Errorf("unexpected function call Open(%s)", url)
 	return nil
 }
+
+func (c *zeroClient) OpenCommand(_ context.Context, url, _ string) error {
+	return c.Open(url)
+}

integration_test/oidcserver/handler/handler.go

@@ -3,11 +3,10 @@ package handler
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"testing"
-
-	"golang.org/x/xerrors"
 )
 
 func New(t *testing.T, provider Provider) *Handler {
@@ -29,7 +28,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.t.Logf("%d %s %s", wr.statusCode, r.Method, r.RequestURI)
 		return
 	}
-	if errResp := new(ErrorResponse); xerrors.As(err, &errResp) {
+	if errResp := new(ErrorResponse); errors.As(err, &errResp) {
 		h.t.Logf("400 %s %s: %s", r.Method, r.RequestURI, err)
 		w.Header().Add("Content-Type", "application/json")
 		w.WriteHeader(400)
@@ -62,14 +61,14 @@ func (h *Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 		w.Header().Add("Content-Type", "application/json")
 		e := json.NewEncoder(w)
 		if err := e.Encode(discoveryResponse); err != nil {
-			return xerrors.Errorf("could not render json: %w", err)
+			return fmt.Errorf("could not render json: %w", err)
 		}
 	case m == "GET" && p == "/certs":
 		certificatesResponse := h.provider.GetCertificates()
 		w.Header().Add("Content-Type", "application/json")
 		e := json.NewEncoder(w)
 		if err := e.Encode(certificatesResponse); err != nil {
-			return xerrors.Errorf("could not render json: %w", err)
+			return fmt.Errorf("could not render json: %w", err)
 		}
 	case m == "GET" && p == "/auth":
 		q := r.URL.Query()
@@ -84,13 +83,13 @@ func (h *Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 			RawQuery:            q,
 		})
 		if err != nil {
-			return xerrors.Errorf("authentication error: %w", err)
+			return fmt.Errorf("authentication error: %w", err)
 		}
 		to := fmt.Sprintf("%s?state=%s&code=%s", redirectURI, state, code)
 		http.Redirect(w, r, to, 302)
 	case m == "POST" && p == "/token":
 		if err := r.ParseForm(); err != nil {
-			return xerrors.Errorf("could not parse the form: %w", err)
+			return fmt.Errorf("could not parse the form: %w", err)
 		}
 		grantType := r.Form.Get("grant_type")
 		switch grantType {
@@ -100,12 +99,12 @@ func (h *Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 				CodeVerifier: r.Form.Get("code_verifier"),
 			})
 			if err != nil {
-				return xerrors.Errorf("token request error: %w", err)
+				return fmt.Errorf("token request error: %w", err)
 			}
 			w.Header().Add("Content-Type", "application/json")
 			e := json.NewEncoder(w)
 			if err := e.Encode(tokenResponse); err != nil {
-				return xerrors.Errorf("could not render json: %w", err)
+				return fmt.Errorf("could not render json: %w", err)
 			}
 		case "password":
 			// 4.3. Resource Owner Password Credentials Grant
@@ -113,12 +112,12 @@ func (h *Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 			username, password, scope := r.Form.Get("username"), r.Form.Get("password"), r.Form.Get("scope")
 			tokenResponse, err := h.provider.AuthenticatePassword(username, password, scope)
 			if err != nil {
-				return xerrors.Errorf("authentication error: %w", err)
+				return fmt.Errorf("authentication error: %w", err)
 			}
 			w.Header().Add("Content-Type", "application/json")
 			e := json.NewEncoder(w)
 			if err := e.Encode(tokenResponse); err != nil {
-				return xerrors.Errorf("could not render json: %w", err)
+				return fmt.Errorf("could not render json: %w", err)
 			}
 		case "refresh_token":
 			// 12.1. Refresh Request
@@ -126,12 +125,12 @@ func (h *Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 			refreshToken := r.Form.Get("refresh_token")
 			tokenResponse, err := h.provider.Refresh(refreshToken)
 			if err != nil {
-				return xerrors.Errorf("token refresh error: %w", err)
+				return fmt.Errorf("token refresh error: %w", err)
 			}
 			w.Header().Add("Content-Type", "application/json")
 			e := json.NewEncoder(w)
 			if err := e.Encode(tokenResponse); err != nil {
-				return xerrors.Errorf("could not render json: %w", err)
+				return fmt.Errorf("could not render json: %w", err)
 			}
 		default:
 			// 5.2. Error Response

integration_test/oidcserver/server.go

@@ -4,6 +4,7 @@ package oidcserver
 import (
 	"crypto/sha256"
 	"encoding/base64"
+	"fmt"
 	"math/big"
 	"strings"
 	"testing"
@@ -13,7 +14,6 @@ import (
 	"github.com/int128/kubelogin/integration_test/oidcserver/handler"
 	"github.com/int128/kubelogin/integration_test/oidcserver/http"
 	"github.com/int128/kubelogin/pkg/testing/jwt"
-	"golang.org/x/xerrors"
 )
 
 type Server interface {
@@ -133,7 +133,7 @@ func (sv *server) AuthenticateCode(req handler.AuthenticationRequest) (code stri
 
 func (sv *server) Exchange(req handler.TokenRequest) (*handler.TokenResponse, error) {
 	if req.Code != "YOUR_AUTH_CODE" {
-		return nil, xerrors.Errorf("code wants %s but was %s", "YOUR_AUTH_CODE", req.Code)
+		return nil, fmt.Errorf("code wants %s but was %s", "YOUR_AUTH_CODE", req.Code)
 	}
 	if sv.lastAuthenticationRequest.CodeChallengeMethod == "S256" {
 		// https://tools.ietf.org/html/rfc7636#section-4.6

integration_test/standalone_test.go

@@ -10,8 +10,8 @@ import (
 	"github.com/int128/kubelogin/integration_test/keypair"
 	"github.com/int128/kubelogin/integration_test/kubeconfig"
 	"github.com/int128/kubelogin/integration_test/oidcserver"
-	"github.com/int128/kubelogin/pkg/adaptors/browser"
 	"github.com/int128/kubelogin/pkg/di"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser"
 	"github.com/int128/kubelogin/pkg/testing/clock"
 	"github.com/int128/kubelogin/pkg/testing/logger"
 )

pkg/adaptors/cmd/cmd_test.go

@@ -1,404 +0,0 @@
-package cmd
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	"github.com/golang/mock/gomock"
-	"github.com/int128/kubelogin/pkg/testing/logger"
-	"github.com/int128/kubelogin/pkg/tlsclientconfig"
-	"github.com/int128/kubelogin/pkg/usecases/authentication"
-	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
-	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
-	"github.com/int128/kubelogin/pkg/usecases/credentialplugin"
-	"github.com/int128/kubelogin/pkg/usecases/credentialplugin/mock_credentialplugin"
-	"github.com/int128/kubelogin/pkg/usecases/standalone"
-	"github.com/int128/kubelogin/pkg/usecases/standalone/mock_standalone"
-)
-
-func TestCmd_Run(t *testing.T) {
-	const executable = "kubelogin"
-	const version = "HEAD"
-
-	t.Run("root", func(t *testing.T) {
-		tests := map[string]struct {
-			args []string
-			in   standalone.Input
-		}{
-			"Defaults": {
-				args: []string{executable},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:           defaultListenAddress,
-							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
-							RedirectURLHostname:   "localhost",
-						},
-					},
-				},
-			},
-			"when --listen-port is set, it should convert the port to address": {
-				args: []string{
-					executable,
-					"--listen-port", "10080",
-					"--listen-port", "20080",
-				},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:           []string{"127.0.0.1:10080", "127.0.0.1:20080"},
-							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
-							RedirectURLHostname:   "localhost",
-						},
-					},
-				},
-			},
-			"when --listen-port is set, it should ignore --listen-address flags": {
-				args: []string{
-					executable,
-					"--listen-port", "10080",
-					"--listen-port", "20080",
-					"--listen-address", "127.0.0.1:30080",
-					"--listen-address", "127.0.0.1:40080",
-				},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:           []string{"127.0.0.1:10080", "127.0.0.1:20080"},
-							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
-							RedirectURLHostname:   "localhost",
-						},
-					},
-				},
-			},
-			"FullOptions": {
-				args: []string{executable,
-					"--kubeconfig", "/path/to/kubeconfig",
-					"--context", "hello.k8s.local",
-					"--user", "google",
-					"--certificate-authority", "/path/to/cacert",
-					"--certificate-authority-data", "BASE64ENCODED",
-					"--insecure-skip-tls-verify",
-					"-v1",
-					"--grant-type", "authcode",
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--skip-open-browser",
-					"--authentication-timeout-sec", "10",
-					"--local-server-cert", "/path/to/local-server-cert",
-					"--local-server-key", "/path/to/local-server-key",
-					"--open-url-after-authentication", "https://example.com/success.html",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: standalone.Input{
-					KubeconfigFilename: "/path/to/kubeconfig",
-					KubeconfigContext:  "hello.k8s.local",
-					KubeconfigUser:     "google",
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:                []string{"127.0.0.1:10080", "127.0.0.1:20080"},
-							SkipOpenBrowser:            true,
-							AuthenticationTimeout:      10 * time.Second,
-							LocalServerCertFile:        "/path/to/local-server-cert",
-							LocalServerKeyFile:         "/path/to/local-server-key",
-							OpenURLAfterAuthentication: "https://example.com/success.html",
-							RedirectURLHostname:        "localhost",
-						},
-					},
-					TLSClientConfig: tlsclientconfig.Config{
-						CACertFilename: []string{"/path/to/cacert"},
-						CACertData:     []string{"BASE64ENCODED"},
-						SkipTLSVerify:  true,
-					},
-				},
-			},
-			"GrantType=authcode-keyboard": {
-				args: []string{executable,
-					"--grant-type", "authcode-keyboard",
-				},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeKeyboardOption: &authcode.KeyboardOption{},
-					},
-				},
-			},
-			"GrantType=password": {
-				args: []string{executable,
-					"--grant-type", "password",
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						ROPCOption: &ropc.Option{
-							Username: "USER",
-							Password: "PASS",
-						},
-					},
-				},
-			},
-			"GrantType=auto": {
-				args: []string{executable,
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: standalone.Input{
-					GrantOptionSet: authentication.GrantOptionSet{
-						ROPCOption: &ropc.Option{
-							Username: "USER",
-							Password: "PASS",
-						},
-					},
-				},
-			},
-		}
-		for name, c := range tests {
-			t.Run(name, func(t *testing.T) {
-				ctrl := gomock.NewController(t)
-				defer ctrl.Finish()
-				ctx := context.TODO()
-				mockStandalone := mock_standalone.NewMockInterface(ctrl)
-				mockStandalone.EXPECT().
-					Do(ctx, c.in)
-				cmd := Cmd{
-					Root: &Root{
-						Standalone: mockStandalone,
-						Logger:     logger.New(t),
-					},
-					Logger: logger.New(t),
-				}
-				exitCode := cmd.Run(ctx, c.args, version)
-				if exitCode != 0 {
-					t.Errorf("exitCode wants 0 but %d", exitCode)
-				}
-			})
-		}
-
-		t.Run("TooManyArgs", func(t *testing.T) {
-			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
-			cmd := Cmd{
-				Root: &Root{
-					Standalone: mock_standalone.NewMockInterface(ctrl),
-					Logger:     logger.New(t),
-				},
-				Logger: logger.New(t),
-			}
-			exitCode := cmd.Run(context.TODO(), []string{executable, "some"}, version)
-			if exitCode != 1 {
-				t.Errorf("exitCode wants 1 but %d", exitCode)
-			}
-		})
-	})
-
-	t.Run("get-token", func(t *testing.T) {
-		tests := map[string]struct {
-			args []string
-			in   credentialplugin.Input
-		}{
-			"Defaults": {
-				args: []string{executable,
-					"get-token",
-					"--oidc-issuer-url", "https://issuer.example.com",
-					"--oidc-client-id", "YOUR_CLIENT_ID",
-				},
-				in: credentialplugin.Input{
-					TokenCacheDir: defaultTokenCacheDir,
-					IssuerURL:     "https://issuer.example.com",
-					ClientID:      "YOUR_CLIENT_ID",
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:           []string{"127.0.0.1:8000", "127.0.0.1:18000"},
-							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
-							RedirectURLHostname:   "localhost",
-						},
-					},
-				},
-			},
-			"FullOptions": {
-				args: []string{executable,
-					"get-token",
-					"--oidc-issuer-url", "https://issuer.example.com",
-					"--oidc-client-id", "YOUR_CLIENT_ID",
-					"--oidc-client-secret", "YOUR_CLIENT_SECRET",
-					"--oidc-extra-scope", "email",
-					"--oidc-extra-scope", "profile",
-					"--certificate-authority", "/path/to/cacert",
-					"--certificate-authority-data", "BASE64ENCODED",
-					"--insecure-skip-tls-verify",
-					"-v1",
-					"--grant-type", "authcode",
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--skip-open-browser",
-					"--authentication-timeout-sec", "10",
-					"--local-server-cert", "/path/to/local-server-cert",
-					"--local-server-key", "/path/to/local-server-key",
-					"--open-url-after-authentication", "https://example.com/success.html",
-					"--oidc-auth-request-extra-params", "ttl=86400",
-					"--oidc-auth-request-extra-params", "reauth=true",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: credentialplugin.Input{
-					TokenCacheDir: defaultTokenCacheDir,
-					IssuerURL:     "https://issuer.example.com",
-					ClientID:      "YOUR_CLIENT_ID",
-					ClientSecret:  "YOUR_CLIENT_SECRET",
-					ExtraScopes:   []string{"email", "profile"},
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeBrowserOption: &authcode.BrowserOption{
-							BindAddress:                []string{"127.0.0.1:10080", "127.0.0.1:20080"},
-							SkipOpenBrowser:            true,
-							AuthenticationTimeout:      10 * time.Second,
-							LocalServerCertFile:        "/path/to/local-server-cert",
-							LocalServerKeyFile:         "/path/to/local-server-key",
-							OpenURLAfterAuthentication: "https://example.com/success.html",
-							RedirectURLHostname:        "localhost",
-							AuthRequestExtraParams:     map[string]string{"ttl": "86400", "reauth": "true"},
-						},
-					},
-					TLSClientConfig: tlsclientconfig.Config{
-						CACertFilename: []string{"/path/to/cacert"},
-						CACertData:     []string{"BASE64ENCODED"},
-						SkipTLSVerify:  true,
-					},
-				},
-			},
-			"GrantType=authcode-keyboard": {
-				args: []string{executable,
-					"get-token",
-					"--oidc-issuer-url", "https://issuer.example.com",
-					"--oidc-client-id", "YOUR_CLIENT_ID",
-					"--grant-type", "authcode-keyboard",
-					"--oidc-auth-request-extra-params", "ttl=86400",
-				},
-				in: credentialplugin.Input{
-					TokenCacheDir: defaultTokenCacheDir,
-					IssuerURL:     "https://issuer.example.com",
-					ClientID:      "YOUR_CLIENT_ID",
-					GrantOptionSet: authentication.GrantOptionSet{
-						AuthCodeKeyboardOption: &authcode.KeyboardOption{
-							AuthRequestExtraParams: map[string]string{"ttl": "86400"},
-						},
-					},
-				},
-			},
-			"GrantType=password": {
-				args: []string{executable,
-					"get-token",
-					"--oidc-issuer-url", "https://issuer.example.com",
-					"--oidc-client-id", "YOUR_CLIENT_ID",
-					"--grant-type", "password",
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: credentialplugin.Input{
-					TokenCacheDir: defaultTokenCacheDir,
-					IssuerURL:     "https://issuer.example.com",
-					ClientID:      "YOUR_CLIENT_ID",
-					GrantOptionSet: authentication.GrantOptionSet{
-						ROPCOption: &ropc.Option{
-							Username: "USER",
-							Password: "PASS",
-						},
-					},
-				},
-			},
-			"GrantType=auto": {
-				args: []string{executable,
-					"get-token",
-					"--oidc-issuer-url", "https://issuer.example.com",
-					"--oidc-client-id", "YOUR_CLIENT_ID",
-					"--listen-address", "127.0.0.1:10080",
-					"--listen-address", "127.0.0.1:20080",
-					"--username", "USER",
-					"--password", "PASS",
-				},
-				in: credentialplugin.Input{
-					TokenCacheDir: defaultTokenCacheDir,
-					IssuerURL:     "https://issuer.example.com",
-					ClientID:      "YOUR_CLIENT_ID",
-					GrantOptionSet: authentication.GrantOptionSet{
-						ROPCOption: &ropc.Option{
-							Username: "USER",
-							Password: "PASS",
-						},
-					},
-				},
-			},
-		}
-		for name, c := range tests {
-			t.Run(name, func(t *testing.T) {
-				ctrl := gomock.NewController(t)
-				defer ctrl.Finish()
-				ctx := context.TODO()
-				getToken := mock_credentialplugin.NewMockInterface(ctrl)
-				getToken.EXPECT().
-					Do(ctx, c.in)
-				cmd := Cmd{
-					Root: &Root{
-						Logger: logger.New(t),
-					},
-					GetToken: &GetToken{
-						GetToken: getToken,
-						Logger:   logger.New(t),
-					},
-					Logger: logger.New(t),
-				}
-				exitCode := cmd.Run(ctx, c.args, version)
-				if exitCode != 0 {
-					t.Errorf("exitCode wants 0 but %d", exitCode)
-				}
-			})
-		}
-
-		t.Run("MissingMandatoryOptions", func(t *testing.T) {
-			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
-			ctx := context.TODO()
-			cmd := Cmd{
-				Root: &Root{
-					Logger: logger.New(t),
-				},
-				GetToken: &GetToken{
-					GetToken: mock_credentialplugin.NewMockInterface(ctrl),
-					Logger:   logger.New(t),
-				},
-				Logger: logger.New(t),
-			}
-			exitCode := cmd.Run(ctx, []string{executable, "get-token"}, version)
-			if exitCode != 1 {
-				t.Errorf("exitCode wants 1 but %d", exitCode)
-			}
-		})
-
-		t.Run("TooManyArgs", func(t *testing.T) {
-			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
-			ctx := context.TODO()
-			cmd := Cmd{
-				Root: &Root{
-					Logger: logger.New(t),
-				},
-				GetToken: &GetToken{
-					GetToken: mock_credentialplugin.NewMockInterface(ctrl),
-					Logger:   logger.New(t),
-				},
-				Logger: logger.New(t),
-			}
-			exitCode := cmd.Run(ctx, []string{executable, "get-token", "foo"}, version)
-			if exitCode != 1 {
-				t.Errorf("exitCode wants 1 but %d", exitCode)
-			}
-		})
-	})
-}

pkg/cmd/authentication.go

@@ -9,7 +9,6 @@ import (
 	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
 	"github.com/spf13/pflag"
-	"golang.org/x/xerrors"
 )
 
 type authenticationOptions struct {
@@ -18,6 +17,7 @@ type authenticationOptions struct {
 	ListenPort                 []int // deprecated
 	AuthenticationTimeoutSec   int
 	SkipOpenBrowser            bool
+	BrowserCommand             string
 	LocalServerCertFile        string
 	LocalServerKeyFile         string
 	OpenURLAfterAuthentication string
@@ -58,6 +58,7 @@ func (o *authenticationOptions) addFlags(f *pflag.FlagSet) {
 		panic(err)
 	}
 	f.BoolVar(&o.SkipOpenBrowser, "skip-open-browser", false, "[authcode] Do not open the browser automatically")
+	f.StringVar(&o.BrowserCommand, "browser-command", "", "[authcode] Command to open the browser")
 	f.IntVar(&o.AuthenticationTimeoutSec, "authentication-timeout-sec", defaultAuthenticationTimeoutSec, "[authcode] Timeout of authentication in seconds")
 	f.StringVar(&o.LocalServerCertFile, "local-server-cert", "", "[authcode] Certificate path for the local server")
 	f.StringVar(&o.LocalServerKeyFile, "local-server-key", "", "[authcode] Certificate key path for the local server")
@@ -68,12 +69,18 @@ func (o *authenticationOptions) addFlags(f *pflag.FlagSet) {
 	f.StringVar(&o.Password, "password", "", "[password] Password for resource owner password credentials grant")
 }
 
+func (o *authenticationOptions) expandHomedir() {
+	o.LocalServerCertFile = expandHomedir(o.LocalServerCertFile)
+	o.LocalServerKeyFile = expandHomedir(o.LocalServerKeyFile)
+}
+
 func (o *authenticationOptions) grantOptionSet() (s authentication.GrantOptionSet, err error) {
 	switch {
 	case o.GrantType == "authcode" || (o.GrantType == "auto" && o.Username == ""):
 		s.AuthCodeBrowserOption = &authcode.BrowserOption{
 			BindAddress:                o.determineListenAddress(),
 			SkipOpenBrowser:            o.SkipOpenBrowser,
+			BrowserCommand:             o.BrowserCommand,
 			AuthenticationTimeout:      time.Duration(o.AuthenticationTimeoutSec) * time.Second,
 			LocalServerCertFile:        o.LocalServerCertFile,
 			LocalServerKeyFile:         o.LocalServerKeyFile,
@@ -91,7 +98,7 @@ func (o *authenticationOptions) grantOptionSet() (s authentication.GrantOptionSe
 			Password: o.Password,
 		}
 	default:
-		err = xerrors.Errorf("grant-type must be one of (%s)", allGrantType)
+		err = fmt.Errorf("grant-type must be one of (%s)", allGrantType)
 	}
 	return
 }

pkg/cmd/authentication_test.go

@@ -0,0 +1,143 @@
+package cmd
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/int128/kubelogin/pkg/usecases/authentication"
+	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
+	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
+	"github.com/spf13/pflag"
+)
+
+func Test_authenticationOptions_grantOptionSet(t *testing.T) {
+	tests := map[string]struct {
+		args []string
+		want authentication.GrantOptionSet
+	}{
+		"NoFlag": {
+			want: authentication.GrantOptionSet{
+				AuthCodeBrowserOption: &authcode.BrowserOption{
+					BindAddress:           defaultListenAddress,
+					AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+					RedirectURLHostname:   "localhost",
+				},
+			},
+		},
+		"FullOptions": {
+			args: []string{
+				"--grant-type", "authcode",
+				"--listen-address", "127.0.0.1:10080",
+				"--listen-address", "127.0.0.1:20080",
+				"--skip-open-browser",
+				"--browser-command", "firefox",
+				"--authentication-timeout-sec", "10",
+				"--local-server-cert", "/path/to/local-server-cert",
+				"--local-server-key", "/path/to/local-server-key",
+				"--open-url-after-authentication", "https://example.com/success.html",
+				"--oidc-redirect-url-hostname", "example",
+				"--oidc-auth-request-extra-params", "ttl=86400",
+				"--oidc-auth-request-extra-params", "reauth=true",
+				"--username", "USER",
+				"--password", "PASS",
+			},
+			want: authentication.GrantOptionSet{
+				AuthCodeBrowserOption: &authcode.BrowserOption{
+					BindAddress:                []string{"127.0.0.1:10080", "127.0.0.1:20080"},
+					SkipOpenBrowser:            true,
+					BrowserCommand:             "firefox",
+					AuthenticationTimeout:      10 * time.Second,
+					LocalServerCertFile:        "/path/to/local-server-cert",
+					LocalServerKeyFile:         "/path/to/local-server-key",
+					OpenURLAfterAuthentication: "https://example.com/success.html",
+					RedirectURLHostname:        "example",
+					AuthRequestExtraParams:     map[string]string{"ttl": "86400", "reauth": "true"},
+				},
+			},
+		},
+		"when --listen-port is set, it should convert the port to address": {
+			args: []string{
+				"--listen-port", "10080",
+				"--listen-port", "20080",
+			},
+			want: authentication.GrantOptionSet{
+				AuthCodeBrowserOption: &authcode.BrowserOption{
+					BindAddress:           []string{"127.0.0.1:10080", "127.0.0.1:20080"},
+					AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+					RedirectURLHostname:   "localhost",
+				},
+			},
+		},
+		"when --listen-port is set, it should ignore --listen-address flags": {
+			args: []string{
+				"--listen-port", "10080",
+				"--listen-port", "20080",
+				"--listen-address", "127.0.0.1:30080",
+				"--listen-address", "127.0.0.1:40080",
+			},
+			want: authentication.GrantOptionSet{
+				AuthCodeBrowserOption: &authcode.BrowserOption{
+					BindAddress:           []string{"127.0.0.1:10080", "127.0.0.1:20080"},
+					AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+					RedirectURLHostname:   "localhost",
+				},
+			},
+		},
+		"GrantType=authcode-keyboard": {
+			args: []string{
+				"--grant-type", "authcode-keyboard",
+			},
+			want: authentication.GrantOptionSet{
+				AuthCodeKeyboardOption: &authcode.KeyboardOption{},
+			},
+		},
+		"GrantType=password": {
+			args: []string{
+				"--grant-type", "password",
+				"--listen-address", "127.0.0.1:10080",
+				"--listen-address", "127.0.0.1:20080",
+				"--username", "USER",
+				"--password", "PASS",
+			},
+			want: authentication.GrantOptionSet{
+				ROPCOption: &ropc.Option{
+					Username: "USER",
+					Password: "PASS",
+				},
+			},
+		},
+		"GrantType=auto": {
+			args: []string{
+				"--listen-address", "127.0.0.1:10080",
+				"--listen-address", "127.0.0.1:20080",
+				"--username", "USER",
+				"--password", "PASS",
+			},
+			want: authentication.GrantOptionSet{
+				ROPCOption: &ropc.Option{
+					Username: "USER",
+					Password: "PASS",
+				},
+			},
+		},
+	}
+
+	for name, c := range tests {
+		t.Run(name, func(t *testing.T) {
+			var o authenticationOptions
+			f := pflag.NewFlagSet("", pflag.ContinueOnError)
+			o.addFlags(f)
+			if err := f.Parse(c.args); err != nil {
+				t.Fatalf("Parse error: %s", err)
+			}
+			got, err := o.grantOptionSet()
+			if err != nil {
+				t.Fatalf("grantOptionSet error: %s", err)
+			}
+			if diff := cmp.Diff(c.want, got); diff != "" {
+				t.Errorf("mismatch (-want +got):\n%s", diff)
+			}
+		})
+	}
+}

pkg/cmd/cmd.go

@@ -2,12 +2,12 @@ package cmd
 
 import (
 	"context"
+	"path/filepath"
 	"runtime"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/spf13/cobra"
-	"k8s.io/client-go/util/homedir"
 )
 
 // Set provides an implementation and interface for Cmd.
@@ -24,7 +24,7 @@ type Interface interface {
 }
 
 var defaultListenAddress = []string{"127.0.0.1:8000", "127.0.0.1:18000"}
-var defaultTokenCacheDir = homedir.HomeDir() + "/.kube/cache/oidc-login"
+var defaultTokenCacheDir = filepath.Join("~", ".kube", "cache", "oidc-login")
 
 const defaultAuthenticationTimeoutSec = 180
 

pkg/cmd/cmd_test.go

@@ -0,0 +1,257 @@
+package cmd
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/golang/mock/gomock"
+	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/testing/logger"
+	"github.com/int128/kubelogin/pkg/tlsclientconfig"
+	"github.com/int128/kubelogin/pkg/usecases/authentication"
+	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
+	"github.com/int128/kubelogin/pkg/usecases/credentialplugin"
+	"github.com/int128/kubelogin/pkg/usecases/credentialplugin/mock_credentialplugin"
+	"github.com/int128/kubelogin/pkg/usecases/standalone"
+	"github.com/int128/kubelogin/pkg/usecases/standalone/mock_standalone"
+)
+
+func TestCmd_Run(t *testing.T) {
+	const executable = "kubelogin"
+	const version = "HEAD"
+
+	t.Run("root", func(t *testing.T) {
+		tests := map[string]struct {
+			args []string
+			in   standalone.Input
+		}{
+			"Defaults": {
+				args: []string{executable},
+				in: standalone.Input{
+					GrantOptionSet: authentication.GrantOptionSet{
+						AuthCodeBrowserOption: &authcode.BrowserOption{
+							BindAddress:           defaultListenAddress,
+							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+							RedirectURLHostname:   "localhost",
+						},
+					},
+				},
+			},
+			"FullOptions": {
+				args: []string{executable,
+					"--kubeconfig", "/path/to/kubeconfig",
+					"--context", "hello.k8s.local",
+					"--user", "google",
+					"-v1",
+				},
+				in: standalone.Input{
+					KubeconfigFilename: "/path/to/kubeconfig",
+					KubeconfigContext:  "hello.k8s.local",
+					KubeconfigUser:     "google",
+					GrantOptionSet: authentication.GrantOptionSet{
+						AuthCodeBrowserOption: &authcode.BrowserOption{
+							BindAddress:           defaultListenAddress,
+							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+							RedirectURLHostname:   "localhost",
+						},
+					},
+				},
+			},
+		}
+		for name, c := range tests {
+			t.Run(name, func(t *testing.T) {
+				ctrl := gomock.NewController(t)
+				defer ctrl.Finish()
+				ctx := context.TODO()
+				mockStandalone := mock_standalone.NewMockInterface(ctrl)
+				mockStandalone.EXPECT().
+					Do(ctx, c.in)
+				cmd := Cmd{
+					Root: &Root{
+						Standalone: mockStandalone,
+						Logger:     logger.New(t),
+					},
+					Logger: logger.New(t),
+				}
+				exitCode := cmd.Run(ctx, c.args, version)
+				if exitCode != 0 {
+					t.Errorf("exitCode wants 0 but %d", exitCode)
+				}
+			})
+		}
+
+		t.Run("TooManyArgs", func(t *testing.T) {
+			ctrl := gomock.NewController(t)
+			defer ctrl.Finish()
+			cmd := Cmd{
+				Root: &Root{
+					Standalone: mock_standalone.NewMockInterface(ctrl),
+					Logger:     logger.New(t),
+				},
+				Logger: logger.New(t),
+			}
+			exitCode := cmd.Run(context.TODO(), []string{executable, "some"}, version)
+			if exitCode != 1 {
+				t.Errorf("exitCode wants 1 but %d", exitCode)
+			}
+		})
+	})
+
+	t.Run("get-token", func(t *testing.T) {
+		userHomeDir, err := os.UserHomeDir()
+		if err != nil {
+			t.Fatalf("os.UserHomeDir error: %s", err)
+		}
+
+		tests := map[string]struct {
+			args []string
+			in   credentialplugin.Input
+		}{
+			"Defaults": {
+				args: []string{executable,
+					"get-token",
+					"--oidc-issuer-url", "https://issuer.example.com",
+					"--oidc-client-id", "YOUR_CLIENT_ID",
+				},
+				in: credentialplugin.Input{
+					TokenCacheDir: filepath.Join(userHomeDir, ".kube/cache/oidc-login"),
+					Provider: oidc.Provider{
+						IssuerURL: "https://issuer.example.com",
+						ClientID:  "YOUR_CLIENT_ID",
+					},
+					GrantOptionSet: authentication.GrantOptionSet{
+						AuthCodeBrowserOption: &authcode.BrowserOption{
+							BindAddress:           defaultListenAddress,
+							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+							RedirectURLHostname:   "localhost",
+						},
+					},
+				},
+			},
+			"FullOptions": {
+				args: []string{executable,
+					"get-token",
+					"--oidc-issuer-url", "https://issuer.example.com",
+					"--oidc-client-id", "YOUR_CLIENT_ID",
+					"--oidc-client-secret", "YOUR_CLIENT_SECRET",
+					"--oidc-extra-scope", "email",
+					"--oidc-extra-scope", "profile",
+					"-v1",
+				},
+				in: credentialplugin.Input{
+					TokenCacheDir: filepath.Join(userHomeDir, ".kube/cache/oidc-login"),
+					Provider: oidc.Provider{
+						IssuerURL:    "https://issuer.example.com",
+						ClientID:     "YOUR_CLIENT_ID",
+						ClientSecret: "YOUR_CLIENT_SECRET",
+						ExtraScopes:  []string{"email", "profile"},
+					},
+					GrantOptionSet: authentication.GrantOptionSet{
+						AuthCodeBrowserOption: &authcode.BrowserOption{
+							BindAddress:           defaultListenAddress,
+							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+							RedirectURLHostname:   "localhost",
+						},
+					},
+				},
+			},
+			"HomedirExpansion": {
+				args: []string{executable,
+					"get-token",
+					"--oidc-issuer-url", "https://issuer.example.com",
+					"--oidc-client-id", "YOUR_CLIENT_ID",
+					"--certificate-authority", "~/.kube/ca.crt",
+					"--local-server-cert", "~/.kube/oidc-server.crt",
+					"--local-server-key", "~/.kube/oidc-server.key",
+					"--token-cache-dir", "~/.kube/oidc-cache",
+				},
+				in: credentialplugin.Input{
+					TokenCacheDir: filepath.Join(userHomeDir, ".kube/oidc-cache"),
+					Provider: oidc.Provider{
+						IssuerURL: "https://issuer.example.com",
+						ClientID:  "YOUR_CLIENT_ID",
+					},
+					GrantOptionSet: authentication.GrantOptionSet{
+						AuthCodeBrowserOption: &authcode.BrowserOption{
+							BindAddress:           defaultListenAddress,
+							AuthenticationTimeout: defaultAuthenticationTimeoutSec * time.Second,
+							RedirectURLHostname:   "localhost",
+							LocalServerCertFile:   filepath.Join(userHomeDir, ".kube/oidc-server.crt"),
+							LocalServerKeyFile:    filepath.Join(userHomeDir, ".kube/oidc-server.key"),
+						},
+					},
+					TLSClientConfig: tlsclientconfig.Config{
+						CACertFilename: []string{filepath.Join(userHomeDir, ".kube/ca.crt")},
+					},
+				},
+			},
+		}
+		for name, c := range tests {
+			t.Run(name, func(t *testing.T) {
+				ctrl := gomock.NewController(t)
+				defer ctrl.Finish()
+				ctx := context.TODO()
+				getToken := mock_credentialplugin.NewMockInterface(ctrl)
+				getToken.EXPECT().
+					Do(ctx, c.in)
+				cmd := Cmd{
+					Root: &Root{
+						Logger: logger.New(t),
+					},
+					GetToken: &GetToken{
+						GetToken: getToken,
+						Logger:   logger.New(t),
+					},
+					Logger: logger.New(t),
+				}
+				exitCode := cmd.Run(ctx, c.args, version)
+				if exitCode != 0 {
+					t.Errorf("exitCode wants 0 but %d", exitCode)
+				}
+			})
+		}
+
+		t.Run("MissingMandatoryOptions", func(t *testing.T) {
+			ctrl := gomock.NewController(t)
+			defer ctrl.Finish()
+			ctx := context.TODO()
+			cmd := Cmd{
+				Root: &Root{
+					Logger: logger.New(t),
+				},
+				GetToken: &GetToken{
+					GetToken: mock_credentialplugin.NewMockInterface(ctrl),
+					Logger:   logger.New(t),
+				},
+				Logger: logger.New(t),
+			}
+			exitCode := cmd.Run(ctx, []string{executable, "get-token"}, version)
+			if exitCode != 1 {
+				t.Errorf("exitCode wants 1 but %d", exitCode)
+			}
+		})
+
+		t.Run("TooManyArgs", func(t *testing.T) {
+			ctrl := gomock.NewController(t)
+			defer ctrl.Finish()
+			ctx := context.TODO()
+			cmd := Cmd{
+				Root: &Root{
+					Logger: logger.New(t),
+				},
+				GetToken: &GetToken{
+					GetToken: mock_credentialplugin.NewMockInterface(ctrl),
+					Logger:   logger.New(t),
+				},
+				Logger: logger.New(t),
+			}
+			exitCode := cmd.Run(ctx, []string{executable, "get-token", "foo"}, version)
+			if exitCode != 1 {
+				t.Errorf("exitCode wants 1 but %d", exitCode)
+			}
+		})
+	})
+}

pkg/cmd/get_token.go

@@ -1,11 +1,14 @@
 package cmd
 
 import (
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"errors"
+	"fmt"
+
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/oidc"
 	"github.com/int128/kubelogin/pkg/usecases/credentialplugin"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
-	"golang.org/x/xerrors"
 )
 
 // getTokenOptions represents the options for get-token command.
@@ -14,6 +17,7 @@ type getTokenOptions struct {
 	ClientID              string
 	ClientSecret          string
 	ExtraScopes           []string
+	UsePKCE               bool
 	TokenCacheDir         string
 	tlsOptions            tlsOptions
 	authenticationOptions authenticationOptions
@@ -24,11 +28,19 @@ func (o *getTokenOptions) addFlags(f *pflag.FlagSet) {
 	f.StringVar(&o.ClientID, "oidc-client-id", "", "Client ID of the provider (mandatory)")
 	f.StringVar(&o.ClientSecret, "oidc-client-secret", "", "Client secret of the provider")
 	f.StringSliceVar(&o.ExtraScopes, "oidc-extra-scope", nil, "Scopes to request to the provider")
+	f.BoolVar(&o.UsePKCE, "oidc-use-pkce", false, "Force PKCE usage")
 	f.StringVar(&o.TokenCacheDir, "token-cache-dir", defaultTokenCacheDir, "Path to a directory for token cache")
 	o.tlsOptions.addFlags(f)
 	o.authenticationOptions.addFlags(f)
 }
 
+func (o *getTokenOptions) expandHomedir() error {
+	o.TokenCacheDir = expandHomedir(o.TokenCacheDir)
+	o.authenticationOptions.expandHomedir()
+	o.tlsOptions.expandHomedir()
+	return nil
+}
+
 type GetToken struct {
 	GetToken credentialplugin.Interface
 	Logger   logger.Interface
@@ -44,29 +56,35 @@ func (cmd *GetToken) New() *cobra.Command {
 				return err
 			}
 			if o.IssuerURL == "" {
-				return xerrors.New("--oidc-issuer-url is missing")
+				return errors.New("--oidc-issuer-url is missing")
 			}
 			if o.ClientID == "" {
-				return xerrors.New("--oidc-client-id is missing")
+				return errors.New("--oidc-client-id is missing")
 			}
 			return nil
 		},
 		RunE: func(c *cobra.Command, _ []string) error {
+			if err := o.expandHomedir(); err != nil {
+				return err
+			}
 			grantOptionSet, err := o.authenticationOptions.grantOptionSet()
 			if err != nil {
-				return xerrors.Errorf("get-token: %w", err)
+				return fmt.Errorf("get-token: %w", err)
 			}
 			in := credentialplugin.Input{
-				IssuerURL:       o.IssuerURL,
-				ClientID:        o.ClientID,
-				ClientSecret:    o.ClientSecret,
-				ExtraScopes:     o.ExtraScopes,
+				Provider: oidc.Provider{
+					IssuerURL:    o.IssuerURL,
+					ClientID:     o.ClientID,
+					ClientSecret: o.ClientSecret,
+					UsePKCE:      o.UsePKCE,
+					ExtraScopes:  o.ExtraScopes,
+				},
 				TokenCacheDir:   o.TokenCacheDir,
 				GrantOptionSet:  grantOptionSet,
 				TLSClientConfig: o.tlsOptions.tlsClientConfig(),
 			}
 			if err := cmd.GetToken.Do(c.Context(), in); err != nil {
-				return xerrors.Errorf("get-token: %w", err)
+				return fmt.Errorf("get-token: %w", err)
 			}
 			return nil
 		},

pkg/cmd/homedir.go

@@ -0,0 +1,15 @@
+package cmd
+
+import (
+	"path/filepath"
+	"strings"
+
+	"k8s.io/client-go/util/homedir"
+)
+
+func expandHomedir(s string) string {
+	if !strings.HasPrefix(s, "~") {
+		return s
+	}
+	return filepath.Join(homedir.HomeDir(), strings.TrimPrefix(s, "~"))
+}

pkg/cmd/root.go

@@ -1,12 +1,12 @@
 package cmd
 
 import (
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"fmt"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
 	"github.com/int128/kubelogin/pkg/usecases/standalone"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
-	"golang.org/x/xerrors"
 )
 
 const rootDescription = `Log in to the OpenID Connect provider.
@@ -51,7 +51,7 @@ func (cmd *Root) New() *cobra.Command {
 		RunE: func(c *cobra.Command, _ []string) error {
 			grantOptionSet, err := o.authenticationOptions.grantOptionSet()
 			if err != nil {
-				return xerrors.Errorf("invalid option: %w", err)
+				return fmt.Errorf("invalid option: %w", err)
 			}
 			in := standalone.Input{
 				KubeconfigFilename: o.Kubeconfig,
@@ -61,7 +61,7 @@ func (cmd *Root) New() *cobra.Command {
 				TLSClientConfig:    o.tlsOptions.tlsClientConfig(),
 			}
 			if err := cmd.Standalone.Do(c.Context(), in); err != nil {
-				return xerrors.Errorf("login: %w", err)
+				return fmt.Errorf("login: %w", err)
 			}
 			return nil
 		},

pkg/cmd/setup.go

@@ -1,10 +1,11 @@
 package cmd
 
 import (
+	"fmt"
+
 	"github.com/int128/kubelogin/pkg/usecases/setup"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
-	"golang.org/x/xerrors"
 )
 
 // setupOptions represents the options for setup command.
@@ -13,6 +14,7 @@ type setupOptions struct {
 	ClientID              string
 	ClientSecret          string
 	ExtraScopes           []string
+	UsePKCE               bool
 	tlsOptions            tlsOptions
 	authenticationOptions authenticationOptions
 }
@@ -22,6 +24,7 @@ func (o *setupOptions) addFlags(f *pflag.FlagSet) {
 	f.StringVar(&o.ClientID, "oidc-client-id", "", "Client ID of the provider")
 	f.StringVar(&o.ClientSecret, "oidc-client-secret", "", "Client secret of the provider")
 	f.StringSliceVar(&o.ExtraScopes, "oidc-extra-scope", nil, "Scopes to request to the provider")
+	f.BoolVar(&o.UsePKCE, "oidc-use-pkce", false, "Force PKCE usage")
 	o.tlsOptions.addFlags(f)
 	o.authenticationOptions.addFlags(f)
 }
@@ -39,13 +42,14 @@ func (cmd *Setup) New() *cobra.Command {
 		RunE: func(c *cobra.Command, _ []string) error {
 			grantOptionSet, err := o.authenticationOptions.grantOptionSet()
 			if err != nil {
-				return xerrors.Errorf("setup: %w", err)
+				return fmt.Errorf("setup: %w", err)
 			}
 			in := setup.Stage2Input{
 				IssuerURL:       o.IssuerURL,
 				ClientID:        o.ClientID,
 				ClientSecret:    o.ClientSecret,
 				ExtraScopes:     o.ExtraScopes,
+				UsePKCE:         o.UsePKCE,
 				GrantOptionSet:  grantOptionSet,
 				TLSClientConfig: o.tlsOptions.tlsClientConfig(),
 			}
@@ -57,7 +61,7 @@ func (cmd *Setup) New() *cobra.Command {
 				return nil
 			}
 			if err := cmd.Setup.DoStage2(c.Context(), in); err != nil {
-				return xerrors.Errorf("setup: %w", err)
+				return fmt.Errorf("setup: %w", err)
 			}
 			return nil
 		},

pkg/cmd/tls.go

@@ -23,6 +23,15 @@ func (o *tlsOptions) addFlags(f *pflag.FlagSet) {
 	f.BoolVar(&o.RenegotiateFreelyAsClient, "tls-renegotiation-freely", false, "If set, allow a remote server to repeatedly request renegotiation")
 }
 
+func (o *tlsOptions) expandHomedir() {
+	var caCertFilenames []string
+	for _, caCertFilename := range o.CACertFilename {
+		expanded := expandHomedir(caCertFilename)
+		caCertFilenames = append(caCertFilenames, expanded)
+	}
+	o.CACertFilename = caCertFilenames
+}
+
 func (o tlsOptions) tlsClientConfig() tlsclientconfig.Config {
 	return tlsclientconfig.Config{
 		CACertFilename: o.CACertFilename,

pkg/credentialplugin/types.go

@@ -0,0 +1,10 @@
+// Package credentialplugin provides the types for client-go credential plugins.
+package credentialplugin
+
+import "time"
+
+// Output represents an output object of the credential plugin.
+type Output struct {
+	Token  string
+	Expiry time.Time
+}

pkg/credentialplugin/writer/credential_plugin.go

@@ -1,18 +1,18 @@
-// Package credentialpluginwriter provides a writer for a credential plugin.
-package credentialpluginwriter
+// Package writer provides a writer for a credential plugin.
+package writer
 
 import (
 	"encoding/json"
-	"time"
+	"fmt"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/stdio"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/credentialplugin"
+	"github.com/int128/kubelogin/pkg/infrastructure/stdio"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	clientauthenticationv1beta1 "k8s.io/client-go/pkg/apis/clientauthentication/v1beta1"
 )
 
-//go:generate mockgen -destination mock_credentialpluginwriter/mock_credentialpluginwriter.go github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter Interface
+//go:generate mockgen -destination mock_writer/mock_writer.go github.com/int128/kubelogin/pkg/credentialplugin/writer Interface
 
 var Set = wire.NewSet(
 	wire.Struct(new(Writer), "*"),
@@ -20,13 +20,7 @@ var Set = wire.NewSet(
 )
 
 type Interface interface {
-	Write(out Output) error
-}
-
-// Output represents an output object of the credential plugin.
-type Output struct {
-	Token  string
-	Expiry time.Time
+	Write(out credentialplugin.Output) error
 }
 
 type Writer struct {
@@ -34,7 +28,7 @@ type Writer struct {
 }
 
 // Write writes the ExecCredential to standard output for kubectl.
-func (w *Writer) Write(out Output) error {
+func (w *Writer) Write(out credentialplugin.Output) error {
 	ec := &clientauthenticationv1beta1.ExecCredential{
 		TypeMeta: metav1.TypeMeta{
 			APIVersion: "client.authentication.k8s.io/v1beta1",
@@ -47,7 +41,7 @@ func (w *Writer) Write(out Output) error {
 	}
 	e := json.NewEncoder(w.Stdout)
 	if err := e.Encode(ec); err != nil {
-		return xerrors.Errorf("could not write the ExecCredential: %w", err)
+		return fmt.Errorf("could not write the ExecCredential: %w", err)
 	}
 	return nil
 }

pkg/credentialplugin/writer/mock_writer/mock_writer.go

@@ -1,47 +1,47 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/credentialplugin/writer (interfaces: Interface)
 
-// Package mock_credentialpluginwriter is a generated GoMock package.
-package mock_credentialpluginwriter
+// Package mock_writer is a generated GoMock package.
+package mock_writer
 
 import (
 	gomock "github.com/golang/mock/gomock"
-	credentialpluginwriter "github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter"
+	credentialplugin "github.com/int128/kubelogin/pkg/credentialplugin"
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// Write mocks base method.
-func (m *MockInterface) Write(arg0 credentialpluginwriter.Output) error {
+// Write mocks base method
+func (m *MockInterface) Write(arg0 credentialplugin.Output) error {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Write", arg0)
 	ret0, _ := ret[0].(error)
 	return ret0
 }
 
-// Write indicates an expected call of Write.
+// Write indicates an expected call of Write
 func (mr *MockInterfaceMockRecorder) Write(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Write", reflect.TypeOf((*MockInterface)(nil).Write), arg0)

pkg/di/di.go

@@ -5,25 +5,26 @@ package di
 
 import (
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/browser"
-	"github.com/int128/kubelogin/pkg/adaptors/clock"
-	"github.com/int128/kubelogin/pkg/adaptors/cmd"
-	"github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter"
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/mutex"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader"
-	"github.com/int128/kubelogin/pkg/adaptors/stdio"
-	"github.com/int128/kubelogin/pkg/adaptors/tokencache"
+	"github.com/int128/kubelogin/pkg/cmd"
+	"github.com/int128/kubelogin/pkg/credentialplugin/writer"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser"
+	"github.com/int128/kubelogin/pkg/infrastructure/clock"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/mutex"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/stdio"
+	kubeconfigLoader "github.com/int128/kubelogin/pkg/kubeconfig/loader"
+	kubeconfigWriter "github.com/int128/kubelogin/pkg/kubeconfig/writer"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig/loader"
+	"github.com/int128/kubelogin/pkg/tokencache/repository"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
 	"github.com/int128/kubelogin/pkg/usecases/credentialplugin"
 	"github.com/int128/kubelogin/pkg/usecases/setup"
 	"github.com/int128/kubelogin/pkg/usecases/standalone"
 )
 
-// NewCmd returns an instance of adaptors.Cmd.
+// NewCmd returns an instance of infrastructure.Cmd.
 func NewCmd() cmd.Interface {
 	wire.Build(
 		NewCmdForHeadless,
@@ -37,7 +38,7 @@ func NewCmd() cmd.Interface {
 	return nil
 }
 
-// NewCmdForHeadless returns an instance of adaptors.Cmd for headless testing.
+// NewCmdForHeadless returns an instance of infrastructure.Cmd for headless testing.
 func NewCmdForHeadless(clock.Interface, stdio.Stdin, stdio.Stdout, logger.Interface, browser.Interface) cmd.Interface {
 	wire.Build(
 		// use-cases
@@ -46,14 +47,15 @@ func NewCmdForHeadless(clock.Interface, stdio.Stdin, stdio.Stdout, logger.Interf
 		credentialplugin.Set,
 		setup.Set,
 
-		// adaptors
+		// infrastructure
 		cmd.Set,
 		reader.Set,
-		kubeconfig.Set,
-		tokencache.Set,
-		oidcclient.Set,
+		kubeconfigLoader.Set,
+		kubeconfigWriter.Set,
+		repository.Set,
+		client.Set,
 		loader.Set,
-		credentialpluginwriter.Set,
+		writer.Set,
 		mutex.Set,
 	)
 	return nil

pkg/di/wire_gen.go

@@ -6,18 +6,19 @@
 package di
 
 import (
-	"github.com/int128/kubelogin/pkg/adaptors/browser"
-	"github.com/int128/kubelogin/pkg/adaptors/clock"
-	"github.com/int128/kubelogin/pkg/adaptors/cmd"
-	"github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter"
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/mutex"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader"
-	"github.com/int128/kubelogin/pkg/adaptors/stdio"
-	"github.com/int128/kubelogin/pkg/adaptors/tokencache"
+	"github.com/int128/kubelogin/pkg/cmd"
+	writer2 "github.com/int128/kubelogin/pkg/credentialplugin/writer"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser"
+	"github.com/int128/kubelogin/pkg/infrastructure/clock"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/mutex"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/stdio"
+	loader2 "github.com/int128/kubelogin/pkg/kubeconfig/loader"
+	"github.com/int128/kubelogin/pkg/kubeconfig/writer"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig/loader"
+	"github.com/int128/kubelogin/pkg/tokencache/repository"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
@@ -29,7 +30,6 @@ import (
 
 // Injectors from di.go:
 
-// NewCmd returns an instance of adaptors.Cmd.
 func NewCmd() cmd.Interface {
 	clockReal := &clock.Real{}
 	stdin := _wireFileValue
@@ -45,10 +45,9 @@ var (
 	_wireOsFileValue = os.Stdout
 )
 
-// NewCmdForHeadless returns an instance of adaptors.Cmd for headless testing.
 func NewCmdForHeadless(clockInterface clock.Interface, stdin stdio.Stdin, stdout stdio.Stdout, loggerInterface logger.Interface, browserInterface browser.Interface) cmd.Interface {
 	loaderLoader := loader.Loader{}
-	factory := &oidcclient.Factory{
+	factory := &client.Factory{
 		Loader: loaderLoader,
 		Clock:  clockInterface,
 		Logger: loggerInterface,
@@ -69,27 +68,27 @@ func NewCmdForHeadless(clockInterface clock.Interface, stdin stdio.Stdin, stdout
 		Logger: loggerInterface,
 	}
 	authenticationAuthentication := &authentication.Authentication{
-		OIDCClient:       factory,
+		ClientFactory:    factory,
 		Logger:           loggerInterface,
 		Clock:            clockInterface,
 		AuthCodeBrowser:  authcodeBrowser,
 		AuthCodeKeyboard: keyboard,
 		ROPC:             ropcROPC,
 	}
-	kubeconfigKubeconfig := &kubeconfig.Kubeconfig{
-		Logger: loggerInterface,
-	}
+	loader3 := &loader2.Loader{}
+	writerWriter := &writer.Writer{}
 	standaloneStandalone := &standalone.Standalone{
-		Authentication: authenticationAuthentication,
-		Kubeconfig:     kubeconfigKubeconfig,
-		Logger:         loggerInterface,
+		Authentication:   authenticationAuthentication,
+		KubeconfigLoader: loader3,
+		KubeconfigWriter: writerWriter,
+		Logger:           loggerInterface,
 	}
 	root := &cmd.Root{
 		Standalone: standaloneStandalone,
 		Logger:     loggerInterface,
 	}
-	repository := &tokencache.Repository{}
-	writer := &credentialpluginwriter.Writer{
+	repositoryRepository := &repository.Repository{}
+	writer3 := &writer2.Writer{
 		Stdout: stdout,
 	}
 	mutexMutex := &mutex.Mutex{
@@ -97,8 +96,8 @@ func NewCmdForHeadless(clockInterface clock.Interface, stdin stdio.Stdin, stdout
 	}
 	getToken := &credentialplugin.GetToken{
 		Authentication:       authenticationAuthentication,
-		TokenCacheRepository: repository,
-		Writer:               writer,
+		TokenCacheRepository: repositoryRepository,
+		Writer:               writer3,
 		Mutex:                mutexMutex,
 		Logger:               loggerInterface,
 	}

pkg/infrastructure/browser/browser.go

@@ -1,13 +1,15 @@
 package browser
 
 import (
+	"context"
 	"os"
+	"os/exec"
 
 	"github.com/google/wire"
 	"github.com/pkg/browser"
 )
 
-//go:generate mockgen -destination mock_browser/mock_browser.go github.com/int128/kubelogin/pkg/adaptors/browser Interface
+//go:generate mockgen -destination mock_browser/mock_browser.go github.com/int128/kubelogin/pkg/infrastructure/browser Interface
 
 func init() {
 	// In credential plugin mode, some browser launcher writes a message to stdout
@@ -23,6 +25,7 @@ var Set = wire.NewSet(
 
 type Interface interface {
 	Open(url string) error
+	OpenCommand(ctx context.Context, url, command string) error
 }
 
 type Browser struct{}
@@ -31,3 +34,11 @@ type Browser struct{}
 func (*Browser) Open(url string) error {
 	return browser.OpenURL(url)
 }
+
+// OpenCommand opens the browser using the command.
+func (*Browser) OpenCommand(ctx context.Context, url, command string) error {
+	c := exec.CommandContext(ctx, command, url)
+	c.Stdout = os.Stderr // see above
+	c.Stderr = os.Stderr
+	return c.Run()
+}

pkg/infrastructure/browser/mock_browser/mock_browser.go

@@ -1,38 +1,39 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/browser (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/infrastructure/browser (interfaces: Interface)
 
 // Package mock_browser is a generated GoMock package.
 package mock_browser
 
 import (
+	context "context"
 	gomock "github.com/golang/mock/gomock"
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// Open mocks base method.
+// Open mocks base method
 func (m *MockInterface) Open(arg0 string) error {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Open", arg0)
@@ -40,8 +41,22 @@ func (m *MockInterface) Open(arg0 string) error {
 	return ret0
 }
 
-// Open indicates an expected call of Open.
+// Open indicates an expected call of Open
 func (mr *MockInterfaceMockRecorder) Open(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Open", reflect.TypeOf((*MockInterface)(nil).Open), arg0)
 }
+
+// OpenCommand mocks base method
+func (m *MockInterface) OpenCommand(arg0 context.Context, arg1, arg2 string) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "OpenCommand", arg0, arg1, arg2)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// OpenCommand indicates an expected call of OpenCommand
+func (mr *MockInterfaceMockRecorder) OpenCommand(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "OpenCommand", reflect.TypeOf((*MockInterface)(nil).OpenCommand), arg0, arg1, arg2)
+}

pkg/infrastructure/logger/logger.go

@@ -7,7 +7,7 @@ import (
 
 	"github.com/google/wire"
 	"github.com/spf13/pflag"
-	"k8s.io/klog"
+	"k8s.io/klog/v2"
 )
 
 // Set provides an implementation and interface for Logger.
@@ -56,5 +56,5 @@ func (*Logger) V(level int) Verbose {
 
 // IsEnabled returns true if the level is enabled.
 func (*Logger) IsEnabled(level int) bool {
-	return bool(klog.V(klog.Level(level)))
+	return klog.V(klog.Level(level)).Enabled()
 }

pkg/infrastructure/mutex/mock_mutex/mock_mutex.go

@@ -1,5 +1,5 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/mutex (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/infrastructure/mutex (interfaces: Interface)
 
 // Package mock_mutex is a generated GoMock package.
 package mock_mutex
@@ -7,7 +7,7 @@ package mock_mutex
 import (
 	context "context"
 	gomock "github.com/golang/mock/gomock"
-	mutex "github.com/int128/kubelogin/pkg/adaptors/mutex"
+	mutex "github.com/int128/kubelogin/pkg/infrastructure/mutex"
 	reflect "reflect"
 )
 

pkg/infrastructure/mutex/mutex.go

@@ -5,13 +5,12 @@ import (
 	"fmt"
 	"github.com/alexflint/go-filemutex"
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"os"
 	"path"
 )
 
-//go:generate mockgen -destination mock_mutex/mock_mutex.go github.com/int128/kubelogin/pkg/adaptors/mutex Interface
+//go:generate mockgen -destination mock_mutex/mock_mutex.go github.com/int128/kubelogin/pkg/infrastructure/mutex Interface
 
 var Set = wire.NewSet(
 	wire.Struct(new(Mutex), "*"),
@@ -64,7 +63,7 @@ func (m *Mutex) Acquire(ctx context.Context, name string) (*Lock, error) {
 	lfn := LockFileName(name)
 	fm, err := filemutex.New(lfn)
 	if err != nil {
-		return nil, xerrors.Errorf("error creating mutex file %s: %w", lfn, err)
+		return nil, fmt.Errorf("error creating mutex file %s: %w", lfn, err)
 	}
 
 	lockChan := internalAcquire(fm)
@@ -75,7 +74,7 @@ func (m *Mutex) Acquire(ctx context.Context, name string) (*Lock, error) {
 	case err := <-lockChan:
 		if err != nil {
 			_ = internalRelease(fm, lfn, m.Logger)
-			return nil, xerrors.Errorf("error acquiring lock on file %s: %w", lfn, err)
+			return nil, fmt.Errorf("error acquiring lock on file %s: %w", lfn, err)
 		}
 		return &Lock{Data: fm, Name: name}, nil
 	}

pkg/infrastructure/mutex/mutex_test.go

@@ -1,9 +1,9 @@
 package mutex
 
 import (
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"fmt"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"golang.org/x/net/context"
-	"golang.org/x/xerrors"
 	"math/rand"
 	"sync"
 	"testing"
@@ -33,10 +33,10 @@ func TestMutex(t *testing.T) {
 				time.Sleep(dur * time.Microsecond)
 				events <- -1
 				if err := m.Release(mutex); err != nil {
-					errors <- xerrors.Errorf("Release error: %w", err)
+					errors <- fmt.Errorf("Release error: %w", err)
 				}
 			} else {
-				errors <- xerrors.Errorf("Acquire error: %w", err)
+				errors <- fmt.Errorf("Acquire error: %w", err)
 			}
 		}
 

pkg/infrastructure/reader/mock_reader/mock_reader.go

@@ -1,5 +1,5 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/reader (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/infrastructure/reader (interfaces: Interface)
 
 // Package mock_reader is a generated GoMock package.
 package mock_reader
@@ -9,30 +9,30 @@ import (
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// ReadPassword mocks base method.
+// ReadPassword mocks base method
 func (m *MockInterface) ReadPassword(arg0 string) (string, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "ReadPassword", arg0)
@@ -41,13 +41,13 @@ func (m *MockInterface) ReadPassword(arg0 string) (string, error) {
 	return ret0, ret1
 }
 
-// ReadPassword indicates an expected call of ReadPassword.
+// ReadPassword indicates an expected call of ReadPassword
 func (mr *MockInterfaceMockRecorder) ReadPassword(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ReadPassword", reflect.TypeOf((*MockInterface)(nil).ReadPassword), arg0)
 }
 
-// ReadString mocks base method.
+// ReadString mocks base method
 func (m *MockInterface) ReadString(arg0 string) (string, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "ReadString", arg0)
@@ -56,7 +56,7 @@ func (m *MockInterface) ReadString(arg0 string) (string, error) {
 	return ret0, ret1
 }
 
-// ReadString indicates an expected call of ReadString.
+// ReadString indicates an expected call of ReadString
 func (mr *MockInterfaceMockRecorder) ReadString(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ReadString", reflect.TypeOf((*MockInterface)(nil).ReadString), arg0)

pkg/infrastructure/reader/reader.go

@@ -9,12 +9,11 @@ import (
 	"syscall"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/stdio"
-	"golang.org/x/crypto/ssh/terminal"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/infrastructure/stdio"
+	"golang.org/x/term"
 )
 
-//go:generate mockgen -destination mock_reader/mock_reader.go github.com/int128/kubelogin/pkg/adaptors/reader Interface
+//go:generate mockgen -destination mock_reader/mock_reader.go github.com/int128/kubelogin/pkg/infrastructure/reader Interface
 
 // Set provides an implementation and interface for Reader.
 var Set = wire.NewSet(
@@ -34,12 +33,12 @@ type Reader struct {
 // ReadString reads a string from the stdin.
 func (x *Reader) ReadString(prompt string) (string, error) {
 	if _, err := fmt.Fprint(os.Stderr, prompt); err != nil {
-		return "", xerrors.Errorf("write error: %w", err)
+		return "", fmt.Errorf("write error: %w", err)
 	}
 	r := bufio.NewReader(x.Stdin)
 	s, err := r.ReadString('\n')
 	if err != nil {
-		return "", xerrors.Errorf("read error: %w", err)
+		return "", fmt.Errorf("read error: %w", err)
 	}
 	s = strings.TrimRight(s, "\r\n")
 	return s, nil
@@ -48,14 +47,14 @@ func (x *Reader) ReadString(prompt string) (string, error) {
 // ReadPassword reads a password from the stdin without echo back.
 func (*Reader) ReadPassword(prompt string) (string, error) {
 	if _, err := fmt.Fprint(os.Stderr, prompt); err != nil {
-		return "", xerrors.Errorf("write error: %w", err)
+		return "", fmt.Errorf("write error: %w", err)
 	}
-	b, err := terminal.ReadPassword(int(syscall.Stdin))
+	b, err := term.ReadPassword(int(syscall.Stdin))
 	if err != nil {
-		return "", xerrors.Errorf("read error: %w", err)
+		return "", fmt.Errorf("read error: %w", err)
 	}
 	if _, err := fmt.Fprintln(os.Stderr); err != nil {
-		return "", xerrors.Errorf("write error: %w", err)
+		return "", fmt.Errorf("write error: %w", err)
 	}
 	return string(b), nil
 }

pkg/jwt/decode.go

@@ -6,10 +6,9 @@ import (
 	"bytes"
 	"encoding/base64"
 	"encoding/json"
+	"fmt"
 	"strings"
 	"time"
-
-	"golang.org/x/xerrors"
 )
 
 // DecodeWithoutVerify decodes the JWT string and returns the claims.
@@ -17,18 +16,18 @@ import (
 func DecodeWithoutVerify(s string) (*Claims, error) {
 	payload, err := DecodePayloadAsRawJSON(s)
 	if err != nil {
-		return nil, xerrors.Errorf("could not decode the payload: %w", err)
+		return nil, fmt.Errorf("could not decode the payload: %w", err)
 	}
 	var claims struct {
 		Subject   string `json:"sub,omitempty"`
 		ExpiresAt int64  `json:"exp,omitempty"`
 	}
 	if err := json.NewDecoder(bytes.NewReader(payload)).Decode(&claims); err != nil {
-		return nil, xerrors.Errorf("could not decode the json of token: %w", err)
+		return nil, fmt.Errorf("could not decode the json of token: %w", err)
 	}
 	var prettyJson bytes.Buffer
 	if err := json.Indent(&prettyJson, payload, "", "  "); err != nil {
-		return nil, xerrors.Errorf("could not indent the json of token: %w", err)
+		return nil, fmt.Errorf("could not indent the json of token: %w", err)
 	}
 	return &Claims{
 		Subject: claims.Subject,
@@ -41,11 +40,11 @@ func DecodeWithoutVerify(s string) (*Claims, error) {
 func DecodePayloadAsPrettyJSON(s string) (string, error) {
 	payload, err := DecodePayloadAsRawJSON(s)
 	if err != nil {
-		return "", xerrors.Errorf("could not decode the payload: %w", err)
+		return "", fmt.Errorf("could not decode the payload: %w", err)
 	}
 	var prettyJson bytes.Buffer
 	if err := json.Indent(&prettyJson, payload, "", "  "); err != nil {
-		return "", xerrors.Errorf("could not indent the json of token: %w", err)
+		return "", fmt.Errorf("could not indent the json of token: %w", err)
 	}
 	return prettyJson.String(), nil
 }
@@ -54,11 +53,11 @@ func DecodePayloadAsPrettyJSON(s string) (string, error) {
 func DecodePayloadAsRawJSON(s string) ([]byte, error) {
 	parts := strings.SplitN(s, ".", 3)
 	if len(parts) != 3 {
-		return nil, xerrors.Errorf("wants %d segments but got %d segments", 3, len(parts))
+		return nil, fmt.Errorf("wants %d segments but got %d segments", 3, len(parts))
 	}
 	payloadJSON, err := decodePayload(parts[1])
 	if err != nil {
-		return nil, xerrors.Errorf("could not decode the payload: %w", err)
+		return nil, fmt.Errorf("could not decode the payload: %w", err)
 	}
 	return payloadJSON, nil
 }
@@ -66,7 +65,7 @@ func DecodePayloadAsRawJSON(s string) ([]byte, error) {
 func decodePayload(payload string) ([]byte, error) {
 	b, err := base64.URLEncoding.WithPadding(base64.NoPadding).DecodeString(payload)
 	if err != nil {
-		return nil, xerrors.Errorf("invalid base64: %w", err)
+		return nil, fmt.Errorf("invalid base64: %w", err)
 	}
 	return b, nil
 }

pkg/kubeconfig/loader/load.go

@@ -1,21 +1,37 @@
-package kubeconfig
+package loader
 
 import (
+	"errors"
+	"fmt"
 	"strings"
 
-	"golang.org/x/xerrors"
+	"github.com/google/wire"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
 	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/client-go/tools/clientcmd/api"
 )
 
-func (*Kubeconfig) GetCurrentAuthProvider(explicitFilename string, contextName ContextName, userName UserName) (*AuthProvider, error) {
+//go:generate mockgen -destination mock_loader/mock_loader.go github.com/int128/kubelogin/pkg/kubeconfig/loader Interface
+
+var Set = wire.NewSet(
+	wire.Struct(new(Loader), "*"),
+	wire.Bind(new(Interface), new(*Loader)),
+)
+
+type Interface interface {
+	GetCurrentAuthProvider(explicitFilename string, contextName kubeconfig.ContextName, userName kubeconfig.UserName) (*kubeconfig.AuthProvider, error)
+}
+
+type Loader struct{}
+
+func (Loader) GetCurrentAuthProvider(explicitFilename string, contextName kubeconfig.ContextName, userName kubeconfig.UserName) (*kubeconfig.AuthProvider, error) {
 	config, err := loadByDefaultRules(explicitFilename)
 	if err != nil {
-		return nil, xerrors.Errorf("could not load the kubeconfig: %w", err)
+		return nil, fmt.Errorf("could not load the kubeconfig: %w", err)
 	}
 	auth, err := findCurrentAuthProvider(config, contextName, userName)
 	if err != nil {
-		return nil, xerrors.Errorf("could not find the current auth provider: %w", err)
+		return nil, fmt.Errorf("could not find the current auth provider: %w", err)
 	}
 	return auth, nil
 }
@@ -25,7 +41,7 @@ func loadByDefaultRules(explicitFilename string) (*api.Config, error) {
 	rules.ExplicitPath = explicitFilename
 	config, err := rules.Load()
 	if err != nil {
-		return nil, xerrors.Errorf("load error: %w", err)
+		return nil, fmt.Errorf("load error: %w", err)
 	}
 	return config, err
 }
@@ -34,29 +50,29 @@ func loadByDefaultRules(explicitFilename string) (*api.Config, error) {
 // If contextName is given, this returns the user of the context.
 // If userName is given, this ignores the context and returns the user.
 // If any context or user is not found, this returns an error.
-func findCurrentAuthProvider(config *api.Config, contextName ContextName, userName UserName) (*AuthProvider, error) {
+func findCurrentAuthProvider(config *api.Config, contextName kubeconfig.ContextName, userName kubeconfig.UserName) (*kubeconfig.AuthProvider, error) {
 	if userName == "" {
 		if contextName == "" {
-			contextName = ContextName(config.CurrentContext)
+			contextName = kubeconfig.ContextName(config.CurrentContext)
 		}
 		contextNode, ok := config.Contexts[string(contextName)]
 		if !ok {
-			return nil, xerrors.Errorf("context %s does not exist", contextName)
+			return nil, fmt.Errorf("context %s does not exist", contextName)
 		}
-		userName = UserName(contextNode.AuthInfo)
+		userName = kubeconfig.UserName(contextNode.AuthInfo)
 	}
 	userNode, ok := config.AuthInfos[string(userName)]
 	if !ok {
-		return nil, xerrors.Errorf("user %s does not exist", userName)
+		return nil, fmt.Errorf("user %s does not exist", userName)
 	}
 	if userNode.AuthProvider == nil {
-		return nil, xerrors.New("auth-provider is missing")
+		return nil, errors.New("auth-provider is missing")
 	}
 	if userNode.AuthProvider.Name != "oidc" {
-		return nil, xerrors.Errorf("auth-provider.name must be oidc but is %s", userNode.AuthProvider.Name)
+		return nil, fmt.Errorf("auth-provider.name must be oidc but is %s", userNode.AuthProvider.Name)
 	}
 	if userNode.AuthProvider.Config == nil {
-		return nil, xerrors.New("auth-provider.config is missing")
+		return nil, errors.New("auth-provider.config is missing")
 	}
 
 	m := userNode.AuthProvider.Config
@@ -64,7 +80,7 @@ func findCurrentAuthProvider(config *api.Config, contextName ContextName, userNa
 	if m["extra-scopes"] != "" {
 		extraScopes = strings.Split(m["extra-scopes"], ",")
 	}
-	return &AuthProvider{
+	return &kubeconfig.AuthProvider{
 		LocationOfOrigin:            userNode.LocationOfOrigin,
 		UserName:                    userName,
 		ContextName:                 contextName,

pkg/kubeconfig/loader/load_test.go

@@ -1,10 +1,11 @@
-package kubeconfig
+package loader
 
 import (
 	"os"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
 	"k8s.io/client-go/tools/clientcmd/api"
 )
 
@@ -105,7 +106,7 @@ func Test_findCurrentAuthProvider(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Could not find the current auth: %s", err)
 		}
-		want := &AuthProvider{
+		want := &kubeconfig.AuthProvider{
 			LocationOfOrigin:            "/path/to/kubeconfig",
 			UserName:                    "theUser",
 			ContextName:                 "theContext",
@@ -145,7 +146,7 @@ func Test_findCurrentAuthProvider(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Could not find the current auth: %s", err)
 		}
-		want := &AuthProvider{
+		want := &kubeconfig.AuthProvider{
 			LocationOfOrigin: "/path/to/kubeconfig",
 			UserName:         "theUser",
 			ContextName:      "theContext",
@@ -173,7 +174,7 @@ func Test_findCurrentAuthProvider(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Could not find the current auth: %s", err)
 		}
-		want := &AuthProvider{
+		want := &kubeconfig.AuthProvider{
 			LocationOfOrigin: "/path/to/kubeconfig",
 			UserName:         "theUser",
 			IDPIssuerURL:     "https://accounts.google.com",

pkg/kubeconfig/loader/mock_loader/mock_loader.go

@@ -1,39 +1,39 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/kubeconfig (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/kubeconfig/loader (interfaces: Interface)
 
-// Package mock_kubeconfig is a generated GoMock package.
-package mock_kubeconfig
+// Package mock_loader is a generated GoMock package.
+package mock_loader
 
 import (
 	gomock "github.com/golang/mock/gomock"
-	kubeconfig "github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
+	kubeconfig "github.com/int128/kubelogin/pkg/kubeconfig"
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// GetCurrentAuthProvider mocks base method.
+// GetCurrentAuthProvider mocks base method
 func (m *MockInterface) GetCurrentAuthProvider(arg0 string, arg1 kubeconfig.ContextName, arg2 kubeconfig.UserName) (*kubeconfig.AuthProvider, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "GetCurrentAuthProvider", arg0, arg1, arg2)
@@ -42,22 +42,8 @@ func (m *MockInterface) GetCurrentAuthProvider(arg0 string, arg1 kubeconfig.Cont
 	return ret0, ret1
 }
 
-// GetCurrentAuthProvider indicates an expected call of GetCurrentAuthProvider.
+// GetCurrentAuthProvider indicates an expected call of GetCurrentAuthProvider
 func (mr *MockInterfaceMockRecorder) GetCurrentAuthProvider(arg0, arg1, arg2 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetCurrentAuthProvider", reflect.TypeOf((*MockInterface)(nil).GetCurrentAuthProvider), arg0, arg1, arg2)
 }
-
-// UpdateAuthProvider mocks base method.
-func (m *MockInterface) UpdateAuthProvider(arg0 *kubeconfig.AuthProvider) error {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "UpdateAuthProvider", arg0)
-	ret0, _ := ret[0].(error)
-	return ret0
-}
-
-// UpdateAuthProvider indicates an expected call of UpdateAuthProvider.
-func (mr *MockInterfaceMockRecorder) UpdateAuthProvider(arg0 interface{}) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateAuthProvider", reflect.TypeOf((*MockInterface)(nil).UpdateAuthProvider), arg0)
-}

pkg/kubeconfig/types.go

@@ -1,23 +1,5 @@
 package kubeconfig
 
-import (
-	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-)
-
-//go:generate mockgen -destination mock_kubeconfig/mock_kubeconfig.go github.com/int128/kubelogin/pkg/adaptors/kubeconfig Interface
-
-// Set provides an implementation and interface for Kubeconfig.
-var Set = wire.NewSet(
-	wire.Struct(new(Kubeconfig), "*"),
-	wire.Bind(new(Interface), new(*Kubeconfig)),
-)
-
-type Interface interface {
-	GetCurrentAuthProvider(explicitFilename string, contextName ContextName, userName UserName) (*AuthProvider, error)
-	UpdateAuthProvider(auth *AuthProvider) error
-}
-
 // ContextName represents name of a context.
 type ContextName string
 
@@ -39,7 +21,3 @@ type AuthProvider struct {
 	IDToken                     string      // (optional) id-token
 	RefreshToken                string      // (optional) refresh-token
 }
-
-type Kubeconfig struct {
-	Logger logger.Interface
-}

pkg/kubeconfig/writer/mock_writer/mock_writer.go

@@ -0,0 +1,48 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/int128/kubelogin/pkg/kubeconfig/writer (interfaces: Interface)
+
+// Package mock_writer is a generated GoMock package.
+package mock_writer
+
+import (
+	gomock "github.com/golang/mock/gomock"
+	kubeconfig "github.com/int128/kubelogin/pkg/kubeconfig"
+	reflect "reflect"
+)
+
+// MockInterface is a mock of Interface interface
+type MockInterface struct {
+	ctrl     *gomock.Controller
+	recorder *MockInterfaceMockRecorder
+}
+
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
+type MockInterfaceMockRecorder struct {
+	mock *MockInterface
+}
+
+// NewMockInterface creates a new mock instance
+func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
+	mock := &MockInterface{ctrl: ctrl}
+	mock.recorder = &MockInterfaceMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
+	return m.recorder
+}
+
+// UpdateAuthProvider mocks base method
+func (m *MockInterface) UpdateAuthProvider(arg0 kubeconfig.AuthProvider) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "UpdateAuthProvider", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// UpdateAuthProvider indicates an expected call of UpdateAuthProvider
+func (mr *MockInterfaceMockRecorder) UpdateAuthProvider(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateAuthProvider", reflect.TypeOf((*MockInterface)(nil).UpdateAuthProvider), arg0)
+}

pkg/kubeconfig/writer/write.go

@@ -1,35 +1,50 @@
-package kubeconfig
+package writer
 
 import (
+	"fmt"
 	"strings"
 
-	"golang.org/x/xerrors"
+	"github.com/google/wire"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
 	"k8s.io/client-go/tools/clientcmd"
 )
 
-func (*Kubeconfig) UpdateAuthProvider(p *AuthProvider) error {
+//go:generate mockgen -destination mock_writer/mock_writer.go github.com/int128/kubelogin/pkg/kubeconfig/writer Interface
+
+var Set = wire.NewSet(
+	wire.Struct(new(Writer), "*"),
+	wire.Bind(new(Interface), new(*Writer)),
+)
+
+type Interface interface {
+	UpdateAuthProvider(p kubeconfig.AuthProvider) error
+}
+
+type Writer struct{}
+
+func (Writer) UpdateAuthProvider(p kubeconfig.AuthProvider) error {
 	config, err := clientcmd.LoadFromFile(p.LocationOfOrigin)
 	if err != nil {
-		return xerrors.Errorf("could not load %s: %w", p.LocationOfOrigin, err)
+		return fmt.Errorf("could not load %s: %w", p.LocationOfOrigin, err)
 	}
 	userNode, ok := config.AuthInfos[string(p.UserName)]
 	if !ok {
-		return xerrors.Errorf("user %s does not exist", p.UserName)
+		return fmt.Errorf("user %s does not exist", p.UserName)
 	}
 	if userNode.AuthProvider == nil {
-		return xerrors.Errorf("auth-provider is missing")
+		return fmt.Errorf("auth-provider is missing")
 	}
 	if userNode.AuthProvider.Name != "oidc" {
-		return xerrors.Errorf("auth-provider must be oidc but is %s", userNode.AuthProvider.Name)
+		return fmt.Errorf("auth-provider must be oidc but is %s", userNode.AuthProvider.Name)
 	}
 	copyAuthProviderConfig(p, userNode.AuthProvider.Config)
 	if err := clientcmd.WriteToFile(*config, p.LocationOfOrigin); err != nil {
-		return xerrors.Errorf("could not update %s: %w", p.LocationOfOrigin, err)
+		return fmt.Errorf("could not update %s: %w", p.LocationOfOrigin, err)
 	}
 	return nil
 }
 
-func copyAuthProviderConfig(p *AuthProvider, m map[string]string) {
+func copyAuthProviderConfig(p kubeconfig.AuthProvider, m map[string]string) {
 	setOrDeleteKey(m, "idp-issuer-url", p.IDPIssuerURL)
 	setOrDeleteKey(m, "client-id", p.ClientID)
 	setOrDeleteKey(m, "client-secret", p.ClientSecret)

pkg/kubeconfig/writer/write_test.go

@@ -1,4 +1,4 @@
-package kubeconfig
+package writer
 
 import (
 	"io/ioutil"
@@ -6,10 +6,11 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
 )
 
 func TestKubeconfig_UpdateAuth(t *testing.T) {
-	var k Kubeconfig
+	var w Writer
 
 	t.Run("MinimumKeys", func(t *testing.T) {
 		f := newKubeconfigFile(t)
@@ -18,7 +19,7 @@ func TestKubeconfig_UpdateAuth(t *testing.T) {
 				t.Errorf("Could not remove the temp file: %s", err)
 			}
 		}()
-		if err := k.UpdateAuthProvider(&AuthProvider{
+		if err := w.UpdateAuthProvider(kubeconfig.AuthProvider{
 			LocationOfOrigin: f.Name(),
 			UserName:         "google",
 			IDPIssuerURL:     "https://accounts.google.com",
@@ -65,7 +66,7 @@ users:
 				t.Errorf("Could not remove the temp file: %s", err)
 			}
 		}()
-		if err := k.UpdateAuthProvider(&AuthProvider{
+		if err := w.UpdateAuthProvider(kubeconfig.AuthProvider{
 			LocationOfOrigin:            f.Name(),
 			UserName:                    "google",
 			IDPIssuerURL:                "https://accounts.google.com",

pkg/oidc/client/client.go

@@ -1,21 +1,21 @@
-package oidcclient
+package client
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"time"
 
-	gooidc "github.com/coreos/go-oidc"
-	"github.com/int128/kubelogin/pkg/adaptors/clock"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	gooidc "github.com/coreos/go-oidc/v3/oidc"
+	"github.com/int128/kubelogin/pkg/infrastructure/clock"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/int128/kubelogin/pkg/oidc"
 	"github.com/int128/kubelogin/pkg/pkce"
 	"github.com/int128/oauth2cli"
 	"golang.org/x/oauth2"
-	"golang.org/x/xerrors"
 )
 
-//go:generate mockgen -destination mock_oidcclient/mock_oidcclient.go github.com/int128/kubelogin/pkg/adaptors/oidcclient Interface
+//go:generate mockgen -destination mock_client/mock_client.go github.com/int128/kubelogin/pkg/oidc/client Interface
 
 type Interface interface {
 	GetAuthCodeURL(in AuthCodeURLInput) string
@@ -87,7 +87,7 @@ func (c *client) GetTokenByAuthCode(ctx context.Context, in GetTokenByAuthCodeIn
 	}
 	token, err := oauth2cli.GetToken(ctx, config)
 	if err != nil {
-		return nil, xerrors.Errorf("oauth2 error: %w", err)
+		return nil, fmt.Errorf("oauth2 error: %w", err)
 	}
 	return c.verifyToken(ctx, token, in.Nonce)
 }
@@ -108,7 +108,7 @@ func (c *client) ExchangeAuthCode(ctx context.Context, in ExchangeAuthCodeInput)
 	opts := tokenRequestOptions(in.PKCEParams)
 	token, err := cfg.Exchange(ctx, in.Code, opts...)
 	if err != nil {
-		return nil, xerrors.Errorf("exchange error: %w", err)
+		return nil, fmt.Errorf("exchange error: %w", err)
 	}
 	return c.verifyToken(ctx, token, in.Nonce)
 }
@@ -148,7 +148,7 @@ func (c *client) GetTokenByROPC(ctx context.Context, username, password string)
 	ctx = c.wrapContext(ctx)
 	token, err := c.oauth2Config.PasswordCredentialsToken(ctx, username, password)
 	if err != nil {
-		return nil, xerrors.Errorf("resource owner password credentials flow error: %w", err)
+		return nil, fmt.Errorf("resource owner password credentials flow error: %w", err)
 	}
 	return c.verifyToken(ctx, token, "")
 }
@@ -163,7 +163,7 @@ func (c *client) Refresh(ctx context.Context, refreshToken string) (*oidc.TokenS
 	source := c.oauth2Config.TokenSource(ctx, currentToken)
 	token, err := source.Token()
 	if err != nil {
-		return nil, xerrors.Errorf("could not refresh the token: %w", err)
+		return nil, fmt.Errorf("could not refresh the token: %w", err)
 	}
 	return c.verifyToken(ctx, token, "")
 }
@@ -173,15 +173,15 @@ func (c *client) Refresh(ctx context.Context, refreshToken string) (*oidc.TokenS
 func (c *client) verifyToken(ctx context.Context, token *oauth2.Token, nonce string) (*oidc.TokenSet, error) {
 	idToken, ok := token.Extra("id_token").(string)
 	if !ok {
-		return nil, xerrors.Errorf("id_token is missing in the token response: %s", token)
+		return nil, fmt.Errorf("id_token is missing in the token response: %s", token)
 	}
 	verifier := c.provider.Verifier(&gooidc.Config{ClientID: c.oauth2Config.ClientID, Now: c.clock.Now})
 	verifiedIDToken, err := verifier.Verify(ctx, idToken)
 	if err != nil {
-		return nil, xerrors.Errorf("could not verify the ID token: %w", err)
+		return nil, fmt.Errorf("could not verify the ID token: %w", err)
 	}
 	if nonce != "" && nonce != verifiedIDToken.Nonce {
-		return nil, xerrors.Errorf("nonce did not match (wants %s but got %s)", nonce, verifiedIDToken.Nonce)
+		return nil, fmt.Errorf("nonce did not match (wants %s but got %s)", nonce, verifiedIDToken.Nonce)
 	}
 	return &oidc.TokenSet{
 		IDToken:      idToken,

pkg/oidc/client/factory.go

@@ -1,24 +1,24 @@
-// Package oidcclient provides a client of OpenID Connect.
-package oidcclient
+// Package client provides a client of OpenID Connect.
+package client
 
 import (
 	"context"
 	"fmt"
 	"net/http"
 
-	gooidc "github.com/coreos/go-oidc"
+	gooidc "github.com/coreos/go-oidc/v3/oidc"
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/clock"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient/logging"
+	"github.com/int128/kubelogin/pkg/infrastructure/clock"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client/logging"
+	"github.com/int128/kubelogin/pkg/pkce"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig/loader"
 	"golang.org/x/oauth2"
-	"golang.org/x/xerrors"
 )
 
-//go:generate mockgen -destination mock_oidcclient/mock_factory.go github.com/int128/kubelogin/pkg/adaptors/oidcclient FactoryInterface
+//go:generate mockgen -destination mock_client/mock_factory.go github.com/int128/kubelogin/pkg/oidc/client FactoryInterface
 
 var Set = wire.NewSet(
 	wire.Struct(new(Factory), "*"),
@@ -35,11 +35,11 @@ type Factory struct {
 	Logger logger.Interface
 }
 
-// New returns an instance of adaptors.Interface with the given configuration.
+// New returns an instance of infrastructure.Interface with the given configuration.
 func (f *Factory) New(ctx context.Context, p oidc.Provider, tlsClientConfig tlsclientconfig.Config) (Interface, error) {
 	rawTLSClientConfig, err := f.Loader.Load(tlsClientConfig)
 	if err != nil {
-		return nil, xerrors.Errorf("could not load the TLS client config: %w", err)
+		return nil, fmt.Errorf("could not load the TLS client config: %w", err)
 	}
 	baseTransport := &http.Transport{
 		TLSClientConfig: rawTLSClientConfig,
@@ -56,11 +56,14 @@ func (f *Factory) New(ctx context.Context, p oidc.Provider, tlsClientConfig tlsc
 	ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient)
 	provider, err := gooidc.NewProvider(ctx, p.IssuerURL)
 	if err != nil {
-		return nil, xerrors.Errorf("oidc discovery error: %w", err)
+		return nil, fmt.Errorf("oidc discovery error: %w", err)
 	}
 	supportedPKCEMethods, err := extractSupportedPKCEMethods(provider)
 	if err != nil {
-		return nil, xerrors.Errorf("could not determine supported PKCE methods: %w", err)
+		return nil, fmt.Errorf("could not determine supported PKCE methods: %w", err)
+	}
+	if len(supportedPKCEMethods) == 0 && p.UsePKCE {
+		supportedPKCEMethods = []string{pkce.MethodS256}
 	}
 	return &client{
 		httpClient: httpClient,

pkg/oidc/client/logging/transport.go

@@ -4,7 +4,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 )
 
 const (

pkg/oidc/client/mock_client/mock_client.go

@@ -1,42 +1,42 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/oidcclient (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/oidc/client (interfaces: Interface)
 
-// Package mock_oidcclient is a generated GoMock package.
-package mock_oidcclient
+// Package mock_client is a generated GoMock package.
+package mock_client
 
 import (
 	context "context"
 	gomock "github.com/golang/mock/gomock"
-	oidcclient "github.com/int128/kubelogin/pkg/adaptors/oidcclient"
 	oidc "github.com/int128/kubelogin/pkg/oidc"
+	client "github.com/int128/kubelogin/pkg/oidc/client"
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// ExchangeAuthCode mocks base method.
-func (m *MockInterface) ExchangeAuthCode(arg0 context.Context, arg1 oidcclient.ExchangeAuthCodeInput) (*oidc.TokenSet, error) {
+// ExchangeAuthCode mocks base method
+func (m *MockInterface) ExchangeAuthCode(arg0 context.Context, arg1 client.ExchangeAuthCodeInput) (*oidc.TokenSet, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "ExchangeAuthCode", arg0, arg1)
 	ret0, _ := ret[0].(*oidc.TokenSet)
@@ -44,28 +44,28 @@ func (m *MockInterface) ExchangeAuthCode(arg0 context.Context, arg1 oidcclient.E
 	return ret0, ret1
 }
 
-// ExchangeAuthCode indicates an expected call of ExchangeAuthCode.
+// ExchangeAuthCode indicates an expected call of ExchangeAuthCode
 func (mr *MockInterfaceMockRecorder) ExchangeAuthCode(arg0, arg1 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ExchangeAuthCode", reflect.TypeOf((*MockInterface)(nil).ExchangeAuthCode), arg0, arg1)
 }
 
-// GetAuthCodeURL mocks base method.
-func (m *MockInterface) GetAuthCodeURL(arg0 oidcclient.AuthCodeURLInput) string {
+// GetAuthCodeURL mocks base method
+func (m *MockInterface) GetAuthCodeURL(arg0 client.AuthCodeURLInput) string {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "GetAuthCodeURL", arg0)
 	ret0, _ := ret[0].(string)
 	return ret0
 }
 
-// GetAuthCodeURL indicates an expected call of GetAuthCodeURL.
+// GetAuthCodeURL indicates an expected call of GetAuthCodeURL
 func (mr *MockInterfaceMockRecorder) GetAuthCodeURL(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetAuthCodeURL", reflect.TypeOf((*MockInterface)(nil).GetAuthCodeURL), arg0)
 }
 
-// GetTokenByAuthCode mocks base method.
-func (m *MockInterface) GetTokenByAuthCode(arg0 context.Context, arg1 oidcclient.GetTokenByAuthCodeInput, arg2 chan<- string) (*oidc.TokenSet, error) {
+// GetTokenByAuthCode mocks base method
+func (m *MockInterface) GetTokenByAuthCode(arg0 context.Context, arg1 client.GetTokenByAuthCodeInput, arg2 chan<- string) (*oidc.TokenSet, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "GetTokenByAuthCode", arg0, arg1, arg2)
 	ret0, _ := ret[0].(*oidc.TokenSet)
@@ -73,13 +73,13 @@ func (m *MockInterface) GetTokenByAuthCode(arg0 context.Context, arg1 oidcclient
 	return ret0, ret1
 }
 
-// GetTokenByAuthCode indicates an expected call of GetTokenByAuthCode.
+// GetTokenByAuthCode indicates an expected call of GetTokenByAuthCode
 func (mr *MockInterfaceMockRecorder) GetTokenByAuthCode(arg0, arg1, arg2 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetTokenByAuthCode", reflect.TypeOf((*MockInterface)(nil).GetTokenByAuthCode), arg0, arg1, arg2)
 }
 
-// GetTokenByROPC mocks base method.
+// GetTokenByROPC mocks base method
 func (m *MockInterface) GetTokenByROPC(arg0 context.Context, arg1, arg2 string) (*oidc.TokenSet, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "GetTokenByROPC", arg0, arg1, arg2)
@@ -88,13 +88,13 @@ func (m *MockInterface) GetTokenByROPC(arg0 context.Context, arg1, arg2 string)
 	return ret0, ret1
 }
 
-// GetTokenByROPC indicates an expected call of GetTokenByROPC.
+// GetTokenByROPC indicates an expected call of GetTokenByROPC
 func (mr *MockInterfaceMockRecorder) GetTokenByROPC(arg0, arg1, arg2 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetTokenByROPC", reflect.TypeOf((*MockInterface)(nil).GetTokenByROPC), arg0, arg1, arg2)
 }
 
-// Refresh mocks base method.
+// Refresh mocks base method
 func (m *MockInterface) Refresh(arg0 context.Context, arg1 string) (*oidc.TokenSet, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Refresh", arg0, arg1)
@@ -103,13 +103,13 @@ func (m *MockInterface) Refresh(arg0 context.Context, arg1 string) (*oidc.TokenS
 	return ret0, ret1
 }
 
-// Refresh indicates an expected call of Refresh.
+// Refresh indicates an expected call of Refresh
 func (mr *MockInterfaceMockRecorder) Refresh(arg0, arg1 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Refresh", reflect.TypeOf((*MockInterface)(nil).Refresh), arg0, arg1)
 }
 
-// SupportedPKCEMethods mocks base method.
+// SupportedPKCEMethods mocks base method
 func (m *MockInterface) SupportedPKCEMethods() []string {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "SupportedPKCEMethods")
@@ -117,7 +117,7 @@ func (m *MockInterface) SupportedPKCEMethods() []string {
 	return ret0
 }
 
-// SupportedPKCEMethods indicates an expected call of SupportedPKCEMethods.
+// SupportedPKCEMethods indicates an expected call of SupportedPKCEMethods
 func (mr *MockInterfaceMockRecorder) SupportedPKCEMethods() *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SupportedPKCEMethods", reflect.TypeOf((*MockInterface)(nil).SupportedPKCEMethods))

pkg/oidc/client/mock_client/mock_factory.go

@@ -1,51 +1,51 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/oidcclient (interfaces: FactoryInterface)
+// Source: github.com/int128/kubelogin/pkg/oidc/client (interfaces: FactoryInterface)
 
-// Package mock_oidcclient is a generated GoMock package.
-package mock_oidcclient
+// Package mock_client is a generated GoMock package.
+package mock_client
 
 import (
 	context "context"
 	gomock "github.com/golang/mock/gomock"
-	oidcclient "github.com/int128/kubelogin/pkg/adaptors/oidcclient"
 	oidc "github.com/int128/kubelogin/pkg/oidc"
+	client "github.com/int128/kubelogin/pkg/oidc/client"
 	tlsclientconfig "github.com/int128/kubelogin/pkg/tlsclientconfig"
 	reflect "reflect"
 )
 
-// MockFactoryInterface is a mock of FactoryInterface interface.
+// MockFactoryInterface is a mock of FactoryInterface interface
 type MockFactoryInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockFactoryInterfaceMockRecorder
 }
 
-// MockFactoryInterfaceMockRecorder is the mock recorder for MockFactoryInterface.
+// MockFactoryInterfaceMockRecorder is the mock recorder for MockFactoryInterface
 type MockFactoryInterfaceMockRecorder struct {
 	mock *MockFactoryInterface
 }
 
-// NewMockFactoryInterface creates a new mock instance.
+// NewMockFactoryInterface creates a new mock instance
 func NewMockFactoryInterface(ctrl *gomock.Controller) *MockFactoryInterface {
 	mock := &MockFactoryInterface{ctrl: ctrl}
 	mock.recorder = &MockFactoryInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockFactoryInterface) EXPECT() *MockFactoryInterfaceMockRecorder {
 	return m.recorder
 }
 
-// New mocks base method.
-func (m *MockFactoryInterface) New(arg0 context.Context, arg1 oidc.Provider, arg2 tlsclientconfig.Config) (oidcclient.Interface, error) {
+// New mocks base method
+func (m *MockFactoryInterface) New(arg0 context.Context, arg1 oidc.Provider, arg2 tlsclientconfig.Config) (client.Interface, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "New", arg0, arg1, arg2)
-	ret0, _ := ret[0].(oidcclient.Interface)
+	ret0, _ := ret[0].(client.Interface)
 	ret1, _ := ret[1].(error)
 	return ret0, ret1
 }
 
-// New indicates an expected call of New.
+// New indicates an expected call of New
 func (mr *MockFactoryInterfaceMockRecorder) New(arg0, arg1, arg2 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "New", reflect.TypeOf((*MockFactoryInterface)(nil).New), arg0, arg1, arg2)

pkg/oidc/oidc.go

@@ -4,9 +4,9 @@ import (
 	"crypto/rand"
 	"encoding/base64"
 	"encoding/binary"
+	"fmt"
 
 	"github.com/int128/kubelogin/pkg/jwt"
-	"golang.org/x/xerrors"
 )
 
 // Provider represents an OIDC provider.
@@ -15,6 +15,7 @@ type Provider struct {
 	ClientID     string
 	ClientSecret string   // optional
 	ExtraScopes  []string // optional
+	UsePKCE      bool     // optional
 }
 
 // TokenSet represents a set of ID token and refresh token.
@@ -30,7 +31,7 @@ func (ts TokenSet) DecodeWithoutVerify() (*jwt.Claims, error) {
 func NewState() (string, error) {
 	b, err := random32()
 	if err != nil {
-		return "", xerrors.Errorf("could not generate a random: %w", err)
+		return "", fmt.Errorf("could not generate a random: %w", err)
 	}
 	return base64URLEncode(b), nil
 }
@@ -38,7 +39,7 @@ func NewState() (string, error) {
 func NewNonce() (string, error) {
 	b, err := random32()
 	if err != nil {
-		return "", xerrors.Errorf("could not generate a random: %w", err)
+		return "", fmt.Errorf("could not generate a random: %w", err)
 	}
 	return base64URLEncode(b), nil
 }
@@ -46,7 +47,7 @@ func NewNonce() (string, error) {
 func random32() ([]byte, error) {
 	b := make([]byte, 32)
 	if err := binary.Read(rand.Reader, binary.LittleEndian, b); err != nil {
-		return nil, xerrors.Errorf("read error: %w", err)
+		return nil, fmt.Errorf("read error: %w", err)
 	}
 	return b, nil
 }

pkg/pkce/pkce.go

@@ -7,15 +7,14 @@ import (
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/binary"
-
-	"golang.org/x/xerrors"
+	"fmt"
 )
 
 var Plain Params
 
 const (
 	// code challenge methods defined as https://tools.ietf.org/html/rfc7636#section-4.3
-	methodS256 = "S256"
+	MethodS256 = "S256"
 )
 
 // Params represents a set of the PKCE parameters.
@@ -34,7 +33,7 @@ func (p Params) IsZero() bool {
 // It returns Plain if no method is available.
 func New(methods []string) (Params, error) {
 	for _, method := range methods {
-		if method == methodS256 {
+		if method == MethodS256 {
 			return NewS256()
 		}
 	}
@@ -45,7 +44,7 @@ func New(methods []string) (Params, error) {
 func NewS256() (Params, error) {
 	b, err := random32()
 	if err != nil {
-		return Plain, xerrors.Errorf("could not generate a random: %w", err)
+		return Plain, fmt.Errorf("could not generate a random: %w", err)
 	}
 	return computeS256(b), nil
 }
@@ -53,7 +52,7 @@ func NewS256() (Params, error) {
 func random32() ([]byte, error) {
 	b := make([]byte, 32)
 	if err := binary.Read(rand.Reader, binary.LittleEndian, b); err != nil {
-		return nil, xerrors.Errorf("read error: %w", err)
+		return nil, fmt.Errorf("read error: %w", err)
 	}
 	return b, nil
 }
@@ -64,7 +63,7 @@ func computeS256(b []byte) Params {
 	_, _ = s.Write([]byte(v))
 	return Params{
 		CodeChallenge:       base64URLEncode(s.Sum(nil)),
-		CodeChallengeMethod: methodS256,
+		CodeChallengeMethod: MethodS256,
 		CodeVerifier:        v,
 	}
 }

pkg/testing/jwt/encode.go

@@ -5,7 +5,7 @@ import (
 	"crypto/rsa"
 	"testing"
 
-	"github.com/dgrijalva/jwt-go"
+	"github.com/golang-jwt/jwt/v4"
 )
 
 var PrivateKey = generateKey(1024)

pkg/testing/logger/logger.go

@@ -3,7 +3,7 @@ package logger
 import (
 	"fmt"
 
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/spf13/pflag"
 )
 

pkg/tlsclientconfig/loader/load.go

@@ -5,11 +5,12 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/base64"
+	"errors"
+	"fmt"
 	"io/ioutil"
 
 	"github.com/google/wire"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
-	"golang.org/x/xerrors"
 )
 
 // Set provides an implementation and interface.
@@ -29,12 +30,12 @@ func (l *Loader) Load(config tlsclientconfig.Config) (*tls.Config, error) {
 	rootCAs := x509.NewCertPool()
 	for _, f := range config.CACertFilename {
 		if err := addFile(rootCAs, f); err != nil {
-			return nil, xerrors.Errorf("could not load the certificate from %s: %w", f, err)
+			return nil, fmt.Errorf("could not load the certificate from %s: %w", f, err)
 		}
 	}
 	for _, d := range config.CACertData {
 		if err := addBase64Encoded(rootCAs, d); err != nil {
-			return nil, xerrors.Errorf("could not load the certificate: %w", err)
+			return nil, fmt.Errorf("could not load the certificate: %w", err)
 		}
 	}
 	if len(rootCAs.Subjects()) == 0 {
@@ -51,10 +52,10 @@ func (l *Loader) Load(config tlsclientconfig.Config) (*tls.Config, error) {
 func addFile(p *x509.CertPool, filename string) error {
 	b, err := ioutil.ReadFile(filename)
 	if err != nil {
-		return xerrors.Errorf("could not read: %w", err)
+		return fmt.Errorf("could not read: %w", err)
 	}
 	if !p.AppendCertsFromPEM(b) {
-		return xerrors.New("invalid certificate")
+		return errors.New("invalid certificate")
 	}
 	return nil
 }
@@ -62,10 +63,10 @@ func addFile(p *x509.CertPool, filename string) error {
 func addBase64Encoded(p *x509.CertPool, s string) error {
 	b, err := base64.StdEncoding.DecodeString(s)
 	if err != nil {
-		return xerrors.Errorf("could not decode base64: %w", err)
+		return fmt.Errorf("could not decode base64: %w", err)
 	}
 	if !p.AppendCertsFromPEM(b) {
-		return xerrors.New("invalid certificate")
+		return errors.New("invalid certificate")
 	}
 	return nil
 }

pkg/tokencache/repository/mock_repository/mock_repository.go

@@ -1,40 +1,40 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/int128/kubelogin/pkg/adaptors/tokencache (interfaces: Interface)
+// Source: github.com/int128/kubelogin/pkg/tokencache/repository (interfaces: Interface)
 
-// Package mock_tokencache is a generated GoMock package.
-package mock_tokencache
+// Package mock_repository is a generated GoMock package.
+package mock_repository
 
 import (
 	gomock "github.com/golang/mock/gomock"
-	tokencache "github.com/int128/kubelogin/pkg/adaptors/tokencache"
 	oidc "github.com/int128/kubelogin/pkg/oidc"
+	tokencache "github.com/int128/kubelogin/pkg/tokencache"
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// FindByKey mocks base method.
+// FindByKey mocks base method
 func (m *MockInterface) FindByKey(arg0 string, arg1 tokencache.Key) (*oidc.TokenSet, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "FindByKey", arg0, arg1)
@@ -43,13 +43,13 @@ func (m *MockInterface) FindByKey(arg0 string, arg1 tokencache.Key) (*oidc.Token
 	return ret0, ret1
 }
 
-// FindByKey indicates an expected call of FindByKey.
+// FindByKey indicates an expected call of FindByKey
 func (mr *MockInterfaceMockRecorder) FindByKey(arg0, arg1 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "FindByKey", reflect.TypeOf((*MockInterface)(nil).FindByKey), arg0, arg1)
 }
 
-// Save mocks base method.
+// Save mocks base method
 func (m *MockInterface) Save(arg0 string, arg1 tokencache.Key, arg2 oidc.TokenSet) error {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Save", arg0, arg1, arg2)
@@ -57,7 +57,7 @@ func (m *MockInterface) Save(arg0 string, arg1 tokencache.Key, arg2 oidc.TokenSe
 	return ret0
 }
 
-// Save indicates an expected call of Save.
+// Save indicates an expected call of Save
 func (mr *MockInterfaceMockRecorder) Save(arg0, arg1, arg2 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Save", reflect.TypeOf((*MockInterface)(nil).Save), arg0, arg1, arg2)

pkg/tokencache/repository/repository.go

@@ -1,19 +1,20 @@
-package tokencache
+package repository
 
 import (
 	"crypto/sha256"
 	"encoding/gob"
 	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"os"
 	"path/filepath"
 
 	"github.com/google/wire"
 	"github.com/int128/kubelogin/pkg/oidc"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/tokencache"
 )
 
-//go:generate mockgen -destination mock_tokencache/mock_tokencache.go github.com/int128/kubelogin/pkg/adaptors/tokencache Interface
+//go:generate mockgen -destination mock_repository/mock_repository.go github.com/int128/kubelogin/pkg/tokencache/repository Interface
 
 // Set provides an implementation and interface for Kubeconfig.
 var Set = wire.NewSet(
@@ -22,20 +23,8 @@ var Set = wire.NewSet(
 )
 
 type Interface interface {
-	FindByKey(dir string, key Key) (*oidc.TokenSet, error)
-	Save(dir string, key Key, tokenSet oidc.TokenSet) error
-}
-
-// Key represents a key of a token cache.
-type Key struct {
-	IssuerURL      string
-	ClientID       string
-	ClientSecret   string
-	Username       string
-	ExtraScopes    []string
-	CACertFilename string
-	CACertData     string
-	SkipTLSVerify  bool
+	FindByKey(dir string, key tokencache.Key) (*oidc.TokenSet, error)
+	Save(dir string, key tokencache.Key, tokenSet oidc.TokenSet) error
 }
 
 type entity struct {
@@ -47,21 +36,21 @@ type entity struct {
 // Filename of a token cache is sha256 digest of the issuer, zero-character and client ID.
 type Repository struct{}
 
-func (r *Repository) FindByKey(dir string, key Key) (*oidc.TokenSet, error) {
+func (r *Repository) FindByKey(dir string, key tokencache.Key) (*oidc.TokenSet, error) {
 	filename, err := computeFilename(key)
 	if err != nil {
-		return nil, xerrors.Errorf("could not compute the key: %w", err)
+		return nil, fmt.Errorf("could not compute the key: %w", err)
 	}
 	p := filepath.Join(dir, filename)
 	f, err := os.Open(p)
 	if err != nil {
-		return nil, xerrors.Errorf("could not open file %s: %w", p, err)
+		return nil, fmt.Errorf("could not open file %s: %w", p, err)
 	}
 	defer f.Close()
 	d := json.NewDecoder(f)
 	var e entity
 	if err := d.Decode(&e); err != nil {
-		return nil, xerrors.Errorf("invalid json file %s: %w", p, err)
+		return nil, fmt.Errorf("invalid json file %s: %w", p, err)
 	}
 	return &oidc.TokenSet{
 		IDToken:      e.IDToken,
@@ -69,18 +58,18 @@ func (r *Repository) FindByKey(dir string, key Key) (*oidc.TokenSet, error) {
 	}, nil
 }
 
-func (r *Repository) Save(dir string, key Key, tokenSet oidc.TokenSet) error {
+func (r *Repository) Save(dir string, key tokencache.Key, tokenSet oidc.TokenSet) error {
 	if err := os.MkdirAll(dir, 0700); err != nil {
-		return xerrors.Errorf("could not create directory %s: %w", dir, err)
+		return fmt.Errorf("could not create directory %s: %w", dir, err)
 	}
 	filename, err := computeFilename(key)
 	if err != nil {
-		return xerrors.Errorf("could not compute the key: %w", err)
+		return fmt.Errorf("could not compute the key: %w", err)
 	}
 	p := filepath.Join(dir, filename)
 	f, err := os.OpenFile(p, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
 	if err != nil {
-		return xerrors.Errorf("could not create file %s: %w", p, err)
+		return fmt.Errorf("could not create file %s: %w", p, err)
 	}
 	defer f.Close()
 	e := entity{
@@ -88,16 +77,16 @@ func (r *Repository) Save(dir string, key Key, tokenSet oidc.TokenSet) error {
 		RefreshToken: tokenSet.RefreshToken,
 	}
 	if err := json.NewEncoder(f).Encode(&e); err != nil {
-		return xerrors.Errorf("json encode error: %w", err)
+		return fmt.Errorf("json encode error: %w", err)
 	}
 	return nil
 }
 
-func computeFilename(key Key) (string, error) {
+func computeFilename(key tokencache.Key) (string, error) {
 	s := sha256.New()
 	e := gob.NewEncoder(s)
 	if err := e.Encode(&key); err != nil {
-		return "", xerrors.Errorf("could not encode the key: %w", err)
+		return "", fmt.Errorf("could not encode the key: %w", err)
 	}
 	h := hex.EncodeToString(s.Sum(nil))
 	return h, nil

pkg/tokencache/repository/repository_test.go

@@ -1,4 +1,4 @@
-package tokencache
+package repository
 
 import (
 	"io/ioutil"
@@ -7,6 +7,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/tokencache"
 )
 
 func TestRepository_FindByKey(t *testing.T) {
@@ -14,7 +15,7 @@ func TestRepository_FindByKey(t *testing.T) {
 
 	t.Run("Success", func(t *testing.T) {
 		dir := t.TempDir()
-		key := Key{
+		key := tokencache.Key{
 			IssuerURL:      "YOUR_ISSUER",
 			ClientID:       "YOUR_CLIENT_ID",
 			ClientSecret:   "YOUR_CLIENT_SECRET",
@@ -48,7 +49,7 @@ func TestRepository_Save(t *testing.T) {
 
 	t.Run("Success", func(t *testing.T) {
 		dir := t.TempDir()
-		key := Key{
+		key := tokencache.Key{
 			IssuerURL:      "YOUR_ISSUER",
 			ClientID:       "YOUR_CLIENT_ID",
 			ClientSecret:   "YOUR_CLIENT_SECRET",

pkg/tokencache/types.go

@@ -0,0 +1,13 @@
+package tokencache
+
+// Key represents a key of a token cache.
+type Key struct {
+	IssuerURL      string
+	ClientID       string
+	ClientSecret   string
+	Username       string
+	ExtraScopes    []string
+	CACertFilename string
+	CACertData     string
+	SkipTLSVerify  bool
+}

pkg/usecases/authentication/authcode/browser.go

@@ -2,19 +2,20 @@ package authcode
 
 import (
 	"context"
+	"fmt"
 	"time"
 
-	"github.com/int128/kubelogin/pkg/adaptors/browser"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 	"github.com/int128/kubelogin/pkg/pkce"
 	"golang.org/x/sync/errgroup"
-	"golang.org/x/xerrors"
 )
 
 type BrowserOption struct {
 	SkipOpenBrowser            bool
+	BrowserCommand             string
 	BindAddress                []string
 	AuthenticationTimeout      time.Duration
 	OpenURLAfterAuthentication string
@@ -30,25 +31,25 @@ type Browser struct {
 	Logger  logger.Interface
 }
 
-func (u *Browser) Do(ctx context.Context, o *BrowserOption, client oidcclient.Interface) (*oidc.TokenSet, error) {
+func (u *Browser) Do(ctx context.Context, o *BrowserOption, oidcClient client.Interface) (*oidc.TokenSet, error) {
 	u.Logger.V(1).Infof("starting the authentication code flow using the browser")
 	state, err := oidc.NewState()
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate a state: %w", err)
+		return nil, fmt.Errorf("could not generate a state: %w", err)
 	}
 	nonce, err := oidc.NewNonce()
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate a nonce: %w", err)
+		return nil, fmt.Errorf("could not generate a nonce: %w", err)
 	}
-	p, err := pkce.New(client.SupportedPKCEMethods())
+	p, err := pkce.New(oidcClient.SupportedPKCEMethods())
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate PKCE parameters: %w", err)
+		return nil, fmt.Errorf("could not generate PKCE parameters: %w", err)
 	}
 	successHTML := BrowserSuccessHTML
 	if o.OpenURLAfterAuthentication != "" {
 		successHTML = BrowserRedirectHTML(o.OpenURLAfterAuthentication)
 	}
-	in := oidcclient.GetTokenByAuthCodeInput{
+	in := client.GetTokenByAuthCodeInput{
 		BindAddress:            o.BindAddress,
 		State:                  state,
 		Nonce:                  nonce,
@@ -71,35 +72,47 @@ func (u *Browser) Do(ctx context.Context, o *BrowserOption, client oidcclient.In
 			if !ok {
 				return nil
 			}
-			if o.SkipOpenBrowser {
-				u.Logger.Printf("Please visit the following URL in your browser: %s", url)
-				return nil
-			}
-			u.Logger.V(1).Infof("opening %s in the browser", url)
-			if err := u.Browser.Open(url); err != nil {
-				u.Logger.Printf(`error: could not open the browser: %s
-
-Please visit the following URL in your browser manually: %s`, err, url)
-				return nil
-			}
+			u.openURL(ctx, o, url)
 			return nil
 		case <-ctx.Done():
-			return xerrors.Errorf("context cancelled while waiting for the local server: %w", ctx.Err())
+			return fmt.Errorf("context cancelled while waiting for the local server: %w", ctx.Err())
 		}
 	})
 	eg.Go(func() error {
 		defer close(readyChan)
-		tokenSet, err := client.GetTokenByAuthCode(ctx, in, readyChan)
+		tokenSet, err := oidcClient.GetTokenByAuthCode(ctx, in, readyChan)
 		if err != nil {
-			return xerrors.Errorf("authorization code flow error: %w", err)
+			return fmt.Errorf("authorization code flow error: %w", err)
 		}
 		out = tokenSet
 		u.Logger.V(1).Infof("got a token set by the authorization code flow")
 		return nil
 	})
 	if err := eg.Wait(); err != nil {
-		return nil, xerrors.Errorf("authentication error: %w", err)
+		return nil, fmt.Errorf("authentication error: %w", err)
 	}
 	u.Logger.V(1).Infof("finished the authorization code flow via the browser")
 	return out, nil
 }
+
+func (u *Browser) openURL(ctx context.Context, o *BrowserOption, url string) {
+	if o.SkipOpenBrowser {
+		u.Logger.Printf("Please visit the following URL in your browser: %s", url)
+		return
+	}
+
+	u.Logger.V(1).Infof("opening %s in the browser", url)
+	if o.BrowserCommand != "" {
+		if err := u.Browser.OpenCommand(ctx, url, o.BrowserCommand); err != nil {
+			u.Logger.Printf(`error: could not open the browser: %s
+
+Please visit the following URL in your browser manually: %s`, err, url)
+		}
+		return
+	}
+	if err := u.Browser.Open(url); err != nil {
+		u.Logger.Printf(`error: could not open the browser: %s
+
+Please visit the following URL in your browser manually: %s`, err, url)
+	}
+}

pkg/usecases/authentication/authcode/browser_test.go

@@ -7,10 +7,10 @@ import (
 
 	"github.com/golang/mock/gomock"
 	"github.com/google/go-cmp/cmp"
-	"github.com/int128/kubelogin/pkg/adaptors/browser/mock_browser"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient/mock_oidcclient"
+	"github.com/int128/kubelogin/pkg/infrastructure/browser/mock_browser"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
+	"github.com/int128/kubelogin/pkg/oidc/client/mock_client"
 	"github.com/int128/kubelogin/pkg/testing/logger"
 )
 
@@ -32,11 +32,11 @@ func TestBrowser_Do(t *testing.T) {
 			RedirectURLHostname:        "localhost",
 			AuthRequestExtraParams:     map[string]string{"ttl": "86400", "reauth": "true"},
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().SupportedPKCEMethods()
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().SupportedPKCEMethods()
+		mockClient.EXPECT().
 			GetTokenByAuthCode(gomock.Any(), gomock.Any(), gomock.Any()).
-			Do(func(_ context.Context, in oidcclient.GetTokenByAuthCodeInput, readyChan chan<- string) {
+			Do(func(_ context.Context, in client.GetTokenByAuthCodeInput, readyChan chan<- string) {
 				if diff := cmp.Diff(o.BindAddress, in.BindAddress); diff != "" {
 					t.Errorf("BindAddress mismatch (-want +got):\n%s", diff)
 				}
@@ -64,7 +64,7 @@ func TestBrowser_Do(t *testing.T) {
 		u := Browser{
 			Logger: logger.New(t),
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}
@@ -86,11 +86,11 @@ func TestBrowser_Do(t *testing.T) {
 			BindAddress:           []string{"127.0.0.1:8000"},
 			AuthenticationTimeout: 10 * time.Second,
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().SupportedPKCEMethods()
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().SupportedPKCEMethods()
+		mockClient.EXPECT().
 			GetTokenByAuthCode(gomock.Any(), gomock.Any(), gomock.Any()).
-			Do(func(_ context.Context, _ oidcclient.GetTokenByAuthCodeInput, readyChan chan<- string) {
+			Do(func(_ context.Context, _ client.GetTokenByAuthCodeInput, readyChan chan<- string) {
 				readyChan <- "LOCAL_SERVER_URL"
 			}).
 			Return(&oidc.TokenSet{
@@ -104,7 +104,48 @@ func TestBrowser_Do(t *testing.T) {
 			Logger:  logger.New(t),
 			Browser: mockBrowser,
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
+		if err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+		want := &oidc.TokenSet{
+			IDToken:      "YOUR_ID_TOKEN",
+			RefreshToken: "YOUR_REFRESH_TOKEN",
+		}
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("mismatch (-want +got):\n%s", diff)
+		}
+	})
+
+	t.Run("OpenBrowserCommand", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx, cancel := context.WithTimeout(context.TODO(), timeout)
+		defer cancel()
+		o := &BrowserOption{
+			BindAddress:           []string{"127.0.0.1:8000"},
+			BrowserCommand:        "firefox",
+			AuthenticationTimeout: 10 * time.Second,
+		}
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().SupportedPKCEMethods()
+		mockClient.EXPECT().
+			GetTokenByAuthCode(gomock.Any(), gomock.Any(), gomock.Any()).
+			Do(func(_ context.Context, _ client.GetTokenByAuthCodeInput, readyChan chan<- string) {
+				readyChan <- "LOCAL_SERVER_URL"
+			}).
+			Return(&oidc.TokenSet{
+				IDToken:      "YOUR_ID_TOKEN",
+				RefreshToken: "YOUR_REFRESH_TOKEN",
+			}, nil)
+		mockBrowser := mock_browser.NewMockInterface(ctrl)
+		mockBrowser.EXPECT().
+			OpenCommand(gomock.Any(), "LOCAL_SERVER_URL", "firefox")
+		u := Browser{
+			Logger:  logger.New(t),
+			Browser: mockBrowser,
+		}
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}

pkg/usecases/authentication/authcode/keyboard.go

@@ -2,13 +2,13 @@ package authcode
 
 import (
 	"context"
+	"fmt"
 
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 	"github.com/int128/kubelogin/pkg/pkce"
-	"golang.org/x/xerrors"
 )
 
 const keyboardPrompt = "Enter code: "
@@ -24,21 +24,21 @@ type Keyboard struct {
 	Logger logger.Interface
 }
 
-func (u *Keyboard) Do(ctx context.Context, o *KeyboardOption, client oidcclient.Interface) (*oidc.TokenSet, error) {
+func (u *Keyboard) Do(ctx context.Context, o *KeyboardOption, oidcClient client.Interface) (*oidc.TokenSet, error) {
 	u.Logger.V(1).Infof("starting the authorization code flow with keyboard interactive")
 	state, err := oidc.NewState()
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate a state: %w", err)
+		return nil, fmt.Errorf("could not generate a state: %w", err)
 	}
 	nonce, err := oidc.NewNonce()
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate a nonce: %w", err)
+		return nil, fmt.Errorf("could not generate a nonce: %w", err)
 	}
-	p, err := pkce.New(client.SupportedPKCEMethods())
+	p, err := pkce.New(oidcClient.SupportedPKCEMethods())
 	if err != nil {
-		return nil, xerrors.Errorf("could not generate PKCE parameters: %w", err)
+		return nil, fmt.Errorf("could not generate PKCE parameters: %w", err)
 	}
-	authCodeURL := client.GetAuthCodeURL(oidcclient.AuthCodeURLInput{
+	authCodeURL := oidcClient.GetAuthCodeURL(client.AuthCodeURLInput{
 		State:                  state,
 		Nonce:                  nonce,
 		PKCEParams:             p,
@@ -48,18 +48,18 @@ func (u *Keyboard) Do(ctx context.Context, o *KeyboardOption, client oidcclient.
 	u.Logger.Printf("Please visit the following URL in your browser: %s", authCodeURL)
 	code, err := u.Reader.ReadString(keyboardPrompt)
 	if err != nil {
-		return nil, xerrors.Errorf("could not read an authorization code: %w", err)
+		return nil, fmt.Errorf("could not read an authorization code: %w", err)
 	}
 
 	u.Logger.V(1).Infof("exchanging the code and token")
-	tokenSet, err := client.ExchangeAuthCode(ctx, oidcclient.ExchangeAuthCodeInput{
+	tokenSet, err := oidcClient.ExchangeAuthCode(ctx, client.ExchangeAuthCodeInput{
 		Code:        code,
 		PKCEParams:  p,
 		Nonce:       nonce,
 		RedirectURI: oobRedirectURI,
 	})
 	if err != nil {
-		return nil, xerrors.Errorf("could not exchange the authorization code: %w", err)
+		return nil, fmt.Errorf("could not exchange the authorization code: %w", err)
 	}
 	u.Logger.V(1).Infof("finished the authorization code flow with keyboard interactive")
 	return tokenSet, nil

pkg/usecases/authentication/authcode/keyboard_test.go

@@ -7,10 +7,10 @@ import (
 
 	"github.com/golang/mock/gomock"
 	"github.com/google/go-cmp/cmp"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient/mock_oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader/mock_reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader/mock_reader"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
+	"github.com/int128/kubelogin/pkg/oidc/client/mock_client"
 	"github.com/int128/kubelogin/pkg/testing/logger"
 )
 
@@ -27,19 +27,19 @@ func TestKeyboard_Do(t *testing.T) {
 		o := &KeyboardOption{
 			AuthRequestExtraParams: map[string]string{"ttl": "86400", "reauth": "true"},
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().SupportedPKCEMethods()
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().SupportedPKCEMethods()
+		mockClient.EXPECT().
 			GetAuthCodeURL(nonNil).
-			Do(func(in oidcclient.AuthCodeURLInput) {
+			Do(func(in client.AuthCodeURLInput) {
 				if diff := cmp.Diff(o.AuthRequestExtraParams, in.AuthRequestExtraParams); diff != "" {
 					t.Errorf("AuthRequestExtraParams mismatch (-want +got):\n%s", diff)
 				}
 			}).
 			Return("https://issuer.example.com/auth")
-		mockOIDCClient.EXPECT().
+		mockClient.EXPECT().
 			ExchangeAuthCode(nonNil, nonNil).
-			Do(func(_ context.Context, in oidcclient.ExchangeAuthCodeInput) {
+			Do(func(_ context.Context, in client.ExchangeAuthCodeInput) {
 				if in.Code != "YOUR_AUTH_CODE" {
 					t.Errorf("Code wants YOUR_AUTH_CODE but was %s", in.Code)
 				}
@@ -56,7 +56,7 @@ func TestKeyboard_Do(t *testing.T) {
 			Reader: mockReader,
 			Logger: logger.New(t),
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}

pkg/usecases/authentication/authentication.go

@@ -2,16 +2,16 @@ package authentication
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/clock"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
+	"github.com/int128/kubelogin/pkg/infrastructure/clock"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
-	"golang.org/x/xerrors"
 )
 
 //go:generate mockgen -destination mock_authentication/mock_authentication.go github.com/int128/kubelogin/pkg/usecases/authentication Interface
@@ -63,7 +63,7 @@ type Output struct {
 // If the Password is not set, it asks a password by the prompt.
 //
 type Authentication struct {
-	OIDCClient       oidcclient.FactoryInterface
+	ClientFactory    client.FactoryInterface
 	Logger           logger.Interface
 	Clock            clock.Interface
 	AuthCodeBrowser  *authcode.Browser
@@ -79,7 +79,7 @@ func (u *Authentication) Do(ctx context.Context, in Input) (*Output, error) {
 		// because the token has been verified before caching.
 		claims, err := in.CachedTokenSet.DecodeWithoutVerify()
 		if err != nil {
-			return nil, xerrors.Errorf("invalid token cache (you may need to remove): %w", err)
+			return nil, fmt.Errorf("invalid token cache (you may need to remove): %w", err)
 		}
 		if !claims.IsExpired(u.Clock) {
 			u.Logger.V(1).Infof("you already have a valid token until %s", claims.Expiry)
@@ -92,14 +92,14 @@ func (u *Authentication) Do(ctx context.Context, in Input) (*Output, error) {
 	}
 
 	u.Logger.V(1).Infof("initializing an OpenID Connect client")
-	client, err := u.OIDCClient.New(ctx, in.Provider, in.TLSClientConfig)
+	oidcClient, err := u.ClientFactory.New(ctx, in.Provider, in.TLSClientConfig)
 	if err != nil {
-		return nil, xerrors.Errorf("oidc error: %w", err)
+		return nil, fmt.Errorf("oidc error: %w", err)
 	}
 
 	if in.CachedTokenSet != nil && in.CachedTokenSet.RefreshToken != "" {
 		u.Logger.V(1).Infof("refreshing the token")
-		tokenSet, err := client.Refresh(ctx, in.CachedTokenSet.RefreshToken)
+		tokenSet, err := oidcClient.Refresh(ctx, in.CachedTokenSet.RefreshToken)
 		if err == nil {
 			return &Output{TokenSet: *tokenSet}, nil
 		}
@@ -107,25 +107,25 @@ func (u *Authentication) Do(ctx context.Context, in Input) (*Output, error) {
 	}
 
 	if in.GrantOptionSet.AuthCodeBrowserOption != nil {
-		tokenSet, err := u.AuthCodeBrowser.Do(ctx, in.GrantOptionSet.AuthCodeBrowserOption, client)
+		tokenSet, err := u.AuthCodeBrowser.Do(ctx, in.GrantOptionSet.AuthCodeBrowserOption, oidcClient)
 		if err != nil {
-			return nil, xerrors.Errorf("authcode-browser error: %w", err)
+			return nil, fmt.Errorf("authcode-browser error: %w", err)
 		}
 		return &Output{TokenSet: *tokenSet}, nil
 	}
 	if in.GrantOptionSet.AuthCodeKeyboardOption != nil {
-		tokenSet, err := u.AuthCodeKeyboard.Do(ctx, in.GrantOptionSet.AuthCodeKeyboardOption, client)
+		tokenSet, err := u.AuthCodeKeyboard.Do(ctx, in.GrantOptionSet.AuthCodeKeyboardOption, oidcClient)
 		if err != nil {
-			return nil, xerrors.Errorf("authcode-keyboard error: %w", err)
+			return nil, fmt.Errorf("authcode-keyboard error: %w", err)
 		}
 		return &Output{TokenSet: *tokenSet}, nil
 	}
 	if in.GrantOptionSet.ROPCOption != nil {
-		tokenSet, err := u.ROPC.Do(ctx, in.GrantOptionSet.ROPCOption, client)
+		tokenSet, err := u.ROPC.Do(ctx, in.GrantOptionSet.ROPCOption, oidcClient)
 		if err != nil {
-			return nil, xerrors.Errorf("ropc error: %w", err)
+			return nil, fmt.Errorf("ropc error: %w", err)
 		}
 		return &Output{TokenSet: *tokenSet}, nil
 	}
-	return nil, xerrors.Errorf("any authorization grant must be set")
+	return nil, fmt.Errorf("any authorization grant must be set")
 }

pkg/usecases/authentication/authentication_test.go

@@ -2,21 +2,21 @@ package authentication
 
 import (
 	"context"
+	"errors"
 	"testing"
 	"time"
 
 	"github.com/golang/mock/gomock"
 	"github.com/google/go-cmp/cmp"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient/mock_oidcclient"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client"
+	"github.com/int128/kubelogin/pkg/oidc/client/mock_client"
 	"github.com/int128/kubelogin/pkg/testing/clock"
 	testingJWT "github.com/int128/kubelogin/pkg/testing/jwt"
 	testingLogger "github.com/int128/kubelogin/pkg/testing/logger"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
-	"golang.org/x/xerrors"
 )
 
 func TestAuthentication_Do(t *testing.T) {
@@ -80,21 +80,21 @@ func TestAuthentication_Do(t *testing.T) {
 				RefreshToken: "VALID_REFRESH_TOKEN",
 			},
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().
 			Refresh(ctx, "VALID_REFRESH_TOKEN").
 			Return(&oidc.TokenSet{
 				IDToken:      "NEW_ID_TOKEN",
 				RefreshToken: "NEW_REFRESH_TOKEN",
 			}, nil)
-		mockOIDCClientFactory := mock_oidcclient.NewMockFactoryInterface(ctrl)
-		mockOIDCClientFactory.EXPECT().
+		mockClientFactory := mock_client.NewMockFactoryInterface(ctrl)
+		mockClientFactory.EXPECT().
 			New(ctx, dummyProvider, dummyTLSClientConfig).
-			Return(mockOIDCClient, nil)
+			Return(mockClient, nil)
 		u := Authentication{
-			OIDCClient: mockOIDCClientFactory,
-			Logger:     testingLogger.New(t),
-			Clock:      clock.Fake(expiryTime.Add(+time.Hour)),
+			ClientFactory: mockClientFactory,
+			Logger:        testingLogger.New(t),
+			Clock:         clock.Fake(expiryTime.Add(+time.Hour)),
 		}
 		got, err := u.Do(ctx, in)
 		if err != nil {
@@ -131,28 +131,28 @@ func TestAuthentication_Do(t *testing.T) {
 				RefreshToken: "EXPIRED_REFRESH_TOKEN",
 			},
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().SupportedPKCEMethods()
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().SupportedPKCEMethods()
+		mockClient.EXPECT().
 			Refresh(ctx, "EXPIRED_REFRESH_TOKEN").
-			Return(nil, xerrors.New("token has expired"))
-		mockOIDCClient.EXPECT().
+			Return(nil, errors.New("token has expired"))
+		mockClient.EXPECT().
 			GetTokenByAuthCode(gomock.Any(), gomock.Any(), gomock.Any()).
-			Do(func(_ context.Context, _ oidcclient.GetTokenByAuthCodeInput, readyChan chan<- string) {
+			Do(func(_ context.Context, _ client.GetTokenByAuthCodeInput, readyChan chan<- string) {
 				readyChan <- "LOCAL_SERVER_URL"
 			}).
 			Return(&oidc.TokenSet{
 				IDToken:      "NEW_ID_TOKEN",
 				RefreshToken: "NEW_REFRESH_TOKEN",
 			}, nil)
-		mockOIDCClientFactory := mock_oidcclient.NewMockFactoryInterface(ctrl)
-		mockOIDCClientFactory.EXPECT().
+		mockClientFactory := mock_client.NewMockFactoryInterface(ctrl)
+		mockClientFactory.EXPECT().
 			New(ctx, dummyProvider, dummyTLSClientConfig).
-			Return(mockOIDCClient, nil)
+			Return(mockClient, nil)
 		u := Authentication{
-			OIDCClient: mockOIDCClientFactory,
-			Logger:     testingLogger.New(t),
-			Clock:      clock.Fake(expiryTime.Add(+time.Hour)),
+			ClientFactory: mockClientFactory,
+			Logger:        testingLogger.New(t),
+			Clock:         clock.Fake(expiryTime.Add(+time.Hour)),
 			AuthCodeBrowser: &authcode.Browser{
 				Logger: testingLogger.New(t),
 			},
@@ -187,20 +187,20 @@ func TestAuthentication_Do(t *testing.T) {
 				},
 			},
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().
 			GetTokenByROPC(gomock.Any(), "USER", "PASS").
 			Return(&oidc.TokenSet{
 				IDToken:      "YOUR_ID_TOKEN",
 				RefreshToken: "YOUR_REFRESH_TOKEN",
 			}, nil)
-		mockOIDCClientFactory := mock_oidcclient.NewMockFactoryInterface(ctrl)
-		mockOIDCClientFactory.EXPECT().
+		mockClientFactory := mock_client.NewMockFactoryInterface(ctrl)
+		mockClientFactory.EXPECT().
 			New(ctx, dummyProvider, dummyTLSClientConfig).
-			Return(mockOIDCClient, nil)
+			Return(mockClient, nil)
 		u := Authentication{
-			OIDCClient: mockOIDCClientFactory,
-			Logger:     testingLogger.New(t),
+			ClientFactory: mockClientFactory,
+			Logger:        testingLogger.New(t),
 			ROPC: &ropc.ROPC{
 				Logger: testingLogger.New(t),
 			},

pkg/usecases/authentication/mock_authentication/mock_authentication.go

@@ -11,30 +11,30 @@ import (
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// Do mocks base method.
+// Do mocks base method
 func (m *MockInterface) Do(arg0 context.Context, arg1 authentication.Input) (*authentication.Output, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Do", arg0, arg1)
@@ -43,7 +43,7 @@ func (m *MockInterface) Do(arg0 context.Context, arg1 authentication.Input) (*au
 	return ret0, ret1
 }
 
-// Do indicates an expected call of Do.
+// Do indicates an expected call of Do
 func (mr *MockInterfaceMockRecorder) Do(arg0, arg1 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Do", reflect.TypeOf((*MockInterface)(nil).Do), arg0, arg1)

pkg/usecases/authentication/ropc/ropc.go

@@ -2,12 +2,12 @@ package ropc
 
 import (
 	"context"
+	"fmt"
 
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader"
 	"github.com/int128/kubelogin/pkg/oidc"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/oidc/client"
 )
 
 const usernamePrompt = "Username: "
@@ -24,25 +24,25 @@ type ROPC struct {
 	Logger logger.Interface
 }
 
-func (u *ROPC) Do(ctx context.Context, in *Option, client oidcclient.Interface) (*oidc.TokenSet, error) {
+func (u *ROPC) Do(ctx context.Context, in *Option, oidcClient client.Interface) (*oidc.TokenSet, error) {
 	u.Logger.V(1).Infof("starting the resource owner password credentials flow")
 	if in.Username == "" {
 		var err error
 		in.Username, err = u.Reader.ReadString(usernamePrompt)
 		if err != nil {
-			return nil, xerrors.Errorf("could not read a username: %w", err)
+			return nil, fmt.Errorf("could not read a username: %w", err)
 		}
 	}
 	if in.Password == "" {
 		var err error
 		in.Password, err = u.Reader.ReadPassword(passwordPrompt)
 		if err != nil {
-			return nil, xerrors.Errorf("could not read a password: %w", err)
+			return nil, fmt.Errorf("could not read a password: %w", err)
 		}
 	}
-	tokenSet, err := client.GetTokenByROPC(ctx, in.Username, in.Password)
+	tokenSet, err := oidcClient.GetTokenByROPC(ctx, in.Username, in.Password)
 	if err != nil {
-		return nil, xerrors.Errorf("resource owner password credentials flow error: %w", err)
+		return nil, fmt.Errorf("resource owner password credentials flow error: %w", err)
 	}
 	u.Logger.V(1).Infof("finished the resource owner password credentials flow")
 	return tokenSet, nil

pkg/usecases/authentication/ropc/ropc_test.go

@@ -2,16 +2,16 @@ package ropc
 
 import (
 	"context"
+	"errors"
 	"testing"
 	"time"
 
 	"github.com/golang/mock/gomock"
 	"github.com/google/go-cmp/cmp"
-	"github.com/int128/kubelogin/pkg/adaptors/oidcclient/mock_oidcclient"
-	"github.com/int128/kubelogin/pkg/adaptors/reader/mock_reader"
+	"github.com/int128/kubelogin/pkg/infrastructure/reader/mock_reader"
 	"github.com/int128/kubelogin/pkg/oidc"
+	"github.com/int128/kubelogin/pkg/oidc/client/mock_client"
 	"github.com/int128/kubelogin/pkg/testing/logger"
-	"golang.org/x/xerrors"
 )
 
 func TestROPC_Do(t *testing.T) {
@@ -23,8 +23,8 @@ func TestROPC_Do(t *testing.T) {
 		ctx, cancel := context.WithTimeout(context.TODO(), timeout)
 		defer cancel()
 		o := &Option{}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().
 			GetTokenByROPC(gomock.Any(), "USER", "PASS").
 			Return(&oidc.TokenSet{
 				IDToken:      "YOUR_ID_TOKEN",
@@ -37,7 +37,7 @@ func TestROPC_Do(t *testing.T) {
 			Reader: mockReader,
 			Logger: logger.New(t),
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}
@@ -59,8 +59,8 @@ func TestROPC_Do(t *testing.T) {
 			Username: "USER",
 			Password: "PASS",
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().
 			GetTokenByROPC(gomock.Any(), "USER", "PASS").
 			Return(&oidc.TokenSet{
 				IDToken:      "YOUR_ID_TOKEN",
@@ -69,7 +69,7 @@ func TestROPC_Do(t *testing.T) {
 		u := ROPC{
 			Logger: logger.New(t),
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}
@@ -90,8 +90,8 @@ func TestROPC_Do(t *testing.T) {
 		o := &Option{
 			Username: "USER",
 		}
-		mockOIDCClient := mock_oidcclient.NewMockInterface(ctrl)
-		mockOIDCClient.EXPECT().
+		mockClient := mock_client.NewMockInterface(ctrl)
+		mockClient.EXPECT().
 			GetTokenByROPC(gomock.Any(), "USER", "PASS").
 			Return(&oidc.TokenSet{
 				IDToken:      "YOUR_ID_TOKEN",
@@ -103,7 +103,7 @@ func TestROPC_Do(t *testing.T) {
 			Reader: mockEnv,
 			Logger: logger.New(t),
 		}
-		got, err := u.Do(ctx, o, mockOIDCClient)
+		got, err := u.Do(ctx, o, mockClient)
 		if err != nil {
 			t.Errorf("Do returned error: %+v", err)
 		}
@@ -125,12 +125,12 @@ func TestROPC_Do(t *testing.T) {
 			Username: "USER",
 		}
 		mockEnv := mock_reader.NewMockInterface(ctrl)
-		mockEnv.EXPECT().ReadPassword(passwordPrompt).Return("", xerrors.New("error"))
+		mockEnv.EXPECT().ReadPassword(passwordPrompt).Return("", errors.New("error"))
 		u := ROPC{
 			Reader: mockEnv,
 			Logger: logger.New(t),
 		}
-		out, err := u.Do(ctx, o, mock_oidcclient.NewMockInterface(ctrl))
+		out, err := u.Do(ctx, o, mock_client.NewMockInterface(ctrl))
 		if err == nil {
 			t.Errorf("err wants non-nil but nil")
 		}

pkg/usecases/credentialplugin/get_token.go

@@ -5,18 +5,21 @@ package credentialplugin
 
 import (
 	"context"
+	"fmt"
+	"net"
 	"strings"
 
-	"github.com/int128/kubelogin/pkg/adaptors/mutex"
-
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
-	"github.com/int128/kubelogin/pkg/adaptors/tokencache"
+	"github.com/int128/kubelogin/pkg/credentialplugin"
+	"github.com/int128/kubelogin/pkg/credentialplugin/writer"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/mutex"
 	"github.com/int128/kubelogin/pkg/oidc"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
+	"github.com/int128/kubelogin/pkg/tokencache"
+	"github.com/int128/kubelogin/pkg/tokencache/repository"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
-	"golang.org/x/xerrors"
+	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 )
 
 //go:generate mockgen -destination mock_credentialplugin/mock_credentialplugin.go github.com/int128/kubelogin/pkg/usecases/credentialplugin Interface
@@ -32,10 +35,7 @@ type Interface interface {
 
 // Input represents an input DTO of the GetToken use-case.
 type Input struct {
-	IssuerURL       string
-	ClientID        string
-	ClientSecret    string
-	ExtraScopes     []string // optional
+	Provider        oidc.Provider
 	TokenCacheDir   string
 	GrantOptionSet  authentication.GrantOptionSet
 	TLSClientConfig tlsclientconfig.Config
@@ -43,8 +43,8 @@ type Input struct {
 
 type GetToken struct {
 	Authentication       authentication.Interface
-	TokenCacheRepository tokencache.Interface
-	Writer               credentialpluginwriter.Interface
+	TokenCacheRepository repository.Interface
+	Writer               writer.Interface
 	Mutex                mutex.Interface
 	Logger               logger.Interface
 }
@@ -52,21 +52,29 @@ type GetToken struct {
 func (u *GetToken) Do(ctx context.Context, in Input) error {
 	u.Logger.V(1).Infof("WARNING: log may contain your secrets such as token or password")
 
-	// Prevent multiple concurrent token query using a file mutex. See https://github.com/int128/kubelogin/issues/389
-	lock, err := u.Mutex.Acquire(ctx, "get-token")
-	if err != nil {
-		return err
+	// Prevent multiple concurrent port binding using a file mutex.
+	// See https://github.com/int128/kubelogin/issues/389
+	bindPorts := extractBindAddressPorts(in.GrantOptionSet.AuthCodeBrowserOption)
+	if bindPorts != nil {
+		key := fmt.Sprintf("get-token-%s", strings.Join(bindPorts, "-"))
+		u.Logger.V(1).Infof("acquiring a lock %s", key)
+		lock, err := u.Mutex.Acquire(ctx, key)
+		if err != nil {
+			return fmt.Errorf("could not acquire a lock: %w", err)
+		}
+		defer func() {
+			if err := u.Mutex.Release(lock); err != nil {
+				u.Logger.V(1).Infof("could not release the lock: %s", err)
+			}
+		}()
 	}
-	defer func() {
-		_ = u.Mutex.Release(lock)
-	}()
 
 	u.Logger.V(1).Infof("finding a token from cache directory %s", in.TokenCacheDir)
 	tokenCacheKey := tokencache.Key{
-		IssuerURL:      in.IssuerURL,
-		ClientID:       in.ClientID,
-		ClientSecret:   in.ClientSecret,
-		ExtraScopes:    in.ExtraScopes,
+		IssuerURL:      in.Provider.IssuerURL,
+		ClientID:       in.Provider.ClientID,
+		ClientSecret:   in.Provider.ClientSecret,
+		ExtraScopes:    in.Provider.ExtraScopes,
 		CACertFilename: strings.Join(in.TLSClientConfig.CACertFilename, ","),
 		CACertData:     strings.Join(in.TLSClientConfig.CACertData, ","),
 		SkipTLSVerify:  in.TLSClientConfig.SkipTLSVerify,
@@ -80,23 +88,18 @@ func (u *GetToken) Do(ctx context.Context, in Input) error {
 	}
 
 	authenticationInput := authentication.Input{
-		Provider: oidc.Provider{
-			IssuerURL:    in.IssuerURL,
-			ClientID:     in.ClientID,
-			ClientSecret: in.ClientSecret,
-			ExtraScopes:  in.ExtraScopes,
-		},
+		Provider:        in.Provider,
 		GrantOptionSet:  in.GrantOptionSet,
 		CachedTokenSet:  cachedTokenSet,
 		TLSClientConfig: in.TLSClientConfig,
 	}
 	authenticationOutput, err := u.Authentication.Do(ctx, authenticationInput)
 	if err != nil {
-		return xerrors.Errorf("authentication error: %w", err)
+		return fmt.Errorf("authentication error: %w", err)
 	}
 	idTokenClaims, err := authenticationOutput.TokenSet.DecodeWithoutVerify()
 	if err != nil {
-		return xerrors.Errorf("you got an invalid token: %w", err)
+		return fmt.Errorf("you got an invalid token: %w", err)
 	}
 	u.Logger.V(1).Infof("you got a token: %s", idTokenClaims.Pretty)
 
@@ -105,16 +108,34 @@ func (u *GetToken) Do(ctx context.Context, in Input) error {
 	} else {
 		u.Logger.V(1).Infof("you got a valid token until %s", idTokenClaims.Expiry)
 		if err := u.TokenCacheRepository.Save(in.TokenCacheDir, tokenCacheKey, authenticationOutput.TokenSet); err != nil {
-			return xerrors.Errorf("could not write the token cache: %w", err)
+			return fmt.Errorf("could not write the token cache: %w", err)
 		}
 	}
 	u.Logger.V(1).Infof("writing the token to client-go")
-	out := credentialpluginwriter.Output{
+	out := credentialplugin.Output{
 		Token:  authenticationOutput.TokenSet.IDToken,
 		Expiry: idTokenClaims.Expiry,
 	}
 	if err := u.Writer.Write(out); err != nil {
-		return xerrors.Errorf("could not write the token to client-go: %w", err)
+		return fmt.Errorf("could not write the token to client-go: %w", err)
 	}
 	return nil
 }
+
+func extractBindAddressPorts(o *authcode.BrowserOption) []string {
+	if o == nil {
+		return nil
+	}
+	var ports []string
+	for _, addr := range o.BindAddress {
+		_, port, err := net.SplitHostPort(addr)
+		if err != nil {
+			return nil // invalid address
+		}
+		if port == "0" {
+			return nil // any port
+		}
+		ports = append(ports, port)
+	}
+	return ports
+}

pkg/usecases/credentialplugin/get_token_test.go

@@ -2,82 +2,87 @@ package credentialplugin
 
 import (
 	"context"
+	"errors"
 	"testing"
 	"time"
 
-	"github.com/int128/kubelogin/pkg/adaptors/mutex"
-	"github.com/int128/kubelogin/pkg/adaptors/mutex/mock_mutex"
+	"github.com/int128/kubelogin/pkg/credentialplugin"
+	"github.com/int128/kubelogin/pkg/infrastructure/mutex"
+	"github.com/int128/kubelogin/pkg/infrastructure/mutex/mock_mutex"
+	"github.com/int128/kubelogin/pkg/usecases/authentication/authcode"
 
 	"github.com/golang/mock/gomock"
-	"github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter"
-	"github.com/int128/kubelogin/pkg/adaptors/credentialpluginwriter/mock_credentialpluginwriter"
-	"github.com/int128/kubelogin/pkg/adaptors/tokencache"
-	"github.com/int128/kubelogin/pkg/adaptors/tokencache/mock_tokencache"
+	"github.com/int128/kubelogin/pkg/credentialplugin/writer/mock_writer"
 	"github.com/int128/kubelogin/pkg/oidc"
 	testingJWT "github.com/int128/kubelogin/pkg/testing/jwt"
 	"github.com/int128/kubelogin/pkg/testing/logger"
-	"github.com/int128/kubelogin/pkg/tlsclientconfig"
+	"github.com/int128/kubelogin/pkg/tokencache"
+	"github.com/int128/kubelogin/pkg/tokencache/repository/mock_repository"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/mock_authentication"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/ropc"
-	"golang.org/x/xerrors"
 )
 
 func TestGetToken_Do(t *testing.T) {
+	dummyProvider := oidc.Provider{
+		IssuerURL:    "https://accounts.google.com",
+		ClientID:     "YOUR_CLIENT_ID",
+		ClientSecret: "YOUR_CLIENT_SECRET",
+	}
 	issuedIDTokenExpiration := time.Now().Add(1 * time.Hour).Round(time.Second)
 	issuedIDToken := testingJWT.EncodeF(t, func(claims *testingJWT.Claims) {
 		claims.Issuer = "https://accounts.google.com"
 		claims.Subject = "YOUR_SUBJECT"
 		claims.ExpiresAt = issuedIDTokenExpiration.Unix()
 	})
+	issuedTokenSet := oidc.TokenSet{
+		IDToken:      issuedIDToken,
+		RefreshToken: "YOUR_REFRESH_TOKEN",
+	}
+	issuedOutput := credentialplugin.Output{
+		Token:  issuedIDToken,
+		Expiry: issuedIDTokenExpiration,
+	}
+	grantOptionSet := authentication.GrantOptionSet{
+		AuthCodeBrowserOption: &authcode.BrowserOption{
+			BindAddress: []string{"127.0.0.1:0"},
+		},
+	}
 
-	t.Run("LeastOptions", func(t *testing.T) {
-		var grantOptionSet authentication.GrantOptionSet
-		tokenSet := oidc.TokenSet{
-			IDToken:      issuedIDToken,
-			RefreshToken: "YOUR_REFRESH_TOKEN",
-		}
+	t.Run("NoTokenCache", func(t *testing.T) {
 		tokenCacheKey := tokencache.Key{
-			IssuerURL: "https://accounts.google.com",
-			ClientID:  "YOUR_CLIENT_ID",
+			IssuerURL:    "https://accounts.google.com",
+			ClientID:     "YOUR_CLIENT_ID",
+			ClientSecret: "YOUR_CLIENT_SECRET",
 		}
-
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 		ctx := context.TODO()
 		in := Input{
-			IssuerURL:      "https://accounts.google.com",
-			ClientID:       "YOUR_CLIENT_ID",
+			Provider:       dummyProvider,
 			TokenCacheDir:  "/path/to/token-cache",
 			GrantOptionSet: grantOptionSet,
 		}
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		mockAuthentication.EXPECT().
 			Do(ctx, authentication.Input{
-				Provider: oidc.Provider{
-					IssuerURL: "https://accounts.google.com",
-					ClientID:  "YOUR_CLIENT_ID",
-				},
+				Provider:       dummyProvider,
 				GrantOptionSet: grantOptionSet,
 			}).
-			Return(&authentication.Output{TokenSet: tokenSet}, nil)
-		tokenCacheRepository := mock_tokencache.NewMockInterface(ctrl)
-		tokenCacheRepository.EXPECT().
+			Return(&authentication.Output{TokenSet: issuedTokenSet}, nil)
+		mockRepository := mock_repository.NewMockInterface(ctrl)
+		mockRepository.EXPECT().
 			FindByKey("/path/to/token-cache", tokenCacheKey).
-			Return(nil, xerrors.New("file not found"))
-		tokenCacheRepository.EXPECT().
-			Save("/path/to/token-cache", tokenCacheKey, tokenSet)
-		credentialPluginWriter := mock_credentialpluginwriter.NewMockInterface(ctrl)
-		credentialPluginWriter.EXPECT().
-			Write(credentialpluginwriter.Output{
-				Token:  issuedIDToken,
-				Expiry: issuedIDTokenExpiration,
-			})
+			Return(nil, errors.New("file not found"))
+		mockRepository.EXPECT().
+			Save("/path/to/token-cache", tokenCacheKey, issuedTokenSet)
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().Write(issuedOutput)
 		u := GetToken{
 			Authentication:       mockAuthentication,
-			TokenCacheRepository: tokenCacheRepository,
-			Writer:               credentialPluginWriter,
-			Mutex:                setupMutexMock(ctrl),
+			TokenCacheRepository: mockRepository,
+			Writer:               mockWriter,
+			Mutex:                mock_mutex.NewMockInterface(ctrl),
 			Logger:               logger.New(t),
 		}
 		if err := u.Do(ctx, in); err != nil {
@@ -85,69 +90,98 @@ func TestGetToken_Do(t *testing.T) {
 		}
 	})
 
-	t.Run("FullOptions", func(t *testing.T) {
+	t.Run("NeedBindPortMutex", func(t *testing.T) {
 		grantOptionSet := authentication.GrantOptionSet{
-			ROPCOption: &ropc.Option{Username: "YOUR_USERNAME"},
-		}
-		tokenSet := oidc.TokenSet{
-			IDToken:      issuedIDToken,
-			RefreshToken: "YOUR_REFRESH_TOKEN",
+			AuthCodeBrowserOption: &authcode.BrowserOption{
+				BindAddress: []string{"127.0.0.1:8080"},
+			},
 		}
 		tokenCacheKey := tokencache.Key{
-			IssuerURL:      "https://accounts.google.com",
-			ClientID:       "YOUR_CLIENT_ID",
-			ClientSecret:   "YOUR_CLIENT_SECRET",
-			Username:       "YOUR_USERNAME",
-			CACertFilename: "/path/to/cert",
-			CACertData:     "BASE64ENCODED",
-			SkipTLSVerify:  true,
-		}
-		tlsClientConfig := tlsclientconfig.Config{
-			CACertFilename: []string{"/path/to/cert"},
-			CACertData:     []string{"BASE64ENCODED"},
-			SkipTLSVerify:  true,
+			IssuerURL:    "https://accounts.google.com",
+			ClientID:     "YOUR_CLIENT_ID",
+			ClientSecret: "YOUR_CLIENT_SECRET",
 		}
 
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 		ctx := context.TODO()
 		in := Input{
-			IssuerURL:       "https://accounts.google.com",
-			ClientID:        "YOUR_CLIENT_ID",
-			ClientSecret:    "YOUR_CLIENT_SECRET",
-			TokenCacheDir:   "/path/to/token-cache",
-			GrantOptionSet:  grantOptionSet,
-			TLSClientConfig: tlsClientConfig,
+			Provider:       dummyProvider,
+			TokenCacheDir:  "/path/to/token-cache",
+			GrantOptionSet: grantOptionSet,
 		}
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		mockAuthentication.EXPECT().
 			Do(ctx, authentication.Input{
-				Provider: oidc.Provider{
-					IssuerURL:    "https://accounts.google.com",
-					ClientID:     "YOUR_CLIENT_ID",
-					ClientSecret: "YOUR_CLIENT_SECRET",
-				},
-				GrantOptionSet:  grantOptionSet,
-				TLSClientConfig: tlsClientConfig,
+				Provider:       dummyProvider,
+				GrantOptionSet: grantOptionSet,
 			}).
-			Return(&authentication.Output{TokenSet: tokenSet}, nil)
-		tokenCacheRepository := mock_tokencache.NewMockInterface(ctrl)
-		tokenCacheRepository.EXPECT().
+			Return(&authentication.Output{TokenSet: issuedTokenSet}, nil)
+		mockRepository := mock_repository.NewMockInterface(ctrl)
+		mockRepository.EXPECT().
 			FindByKey("/path/to/token-cache", tokenCacheKey).
-			Return(nil, xerrors.New("file not found"))
-		tokenCacheRepository.EXPECT().
-			Save("/path/to/token-cache", tokenCacheKey, tokenSet)
-		credentialPluginWriter := mock_credentialpluginwriter.NewMockInterface(ctrl)
-		credentialPluginWriter.EXPECT().
-			Write(credentialpluginwriter.Output{
-				Token:  issuedIDToken,
-				Expiry: issuedIDTokenExpiration,
-			})
+			Return(nil, errors.New("file not found"))
+		mockRepository.EXPECT().
+			Save("/path/to/token-cache", tokenCacheKey, issuedTokenSet)
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().Write(issuedOutput)
+		mockMutex := mock_mutex.NewMockInterface(ctrl)
+		mockMutex.EXPECT().
+			Acquire(ctx, "get-token-8080").
+			Return(&mutex.Lock{Data: "testData"}, nil)
+		mockMutex.EXPECT().
+			Release(&mutex.Lock{Data: "testData"})
 		u := GetToken{
 			Authentication:       mockAuthentication,
-			TokenCacheRepository: tokenCacheRepository,
-			Writer:               credentialPluginWriter,
-			Mutex:                setupMutexMock(ctrl),
+			TokenCacheRepository: mockRepository,
+			Writer:               mockWriter,
+			Mutex:                mockMutex,
+			Logger:               logger.New(t),
+		}
+		if err := u.Do(ctx, in); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("ROPC", func(t *testing.T) {
+		grantOptionSet := authentication.GrantOptionSet{
+			ROPCOption: &ropc.Option{Username: "YOUR_USERNAME"},
+		}
+		tokenCacheKey := tokencache.Key{
+			IssuerURL:    "https://accounts.google.com",
+			ClientID:     "YOUR_CLIENT_ID",
+			ClientSecret: "YOUR_CLIENT_SECRET",
+			Username:     "YOUR_USERNAME",
+		}
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+		in := Input{
+			Provider:       dummyProvider,
+			TokenCacheDir:  "/path/to/token-cache",
+			GrantOptionSet: grantOptionSet,
+		}
+		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
+		mockAuthentication.EXPECT().
+			Do(ctx, authentication.Input{
+				Provider:       dummyProvider,
+				GrantOptionSet: grantOptionSet,
+			}).
+			Return(&authentication.Output{TokenSet: issuedTokenSet}, nil)
+		mockRepository := mock_repository.NewMockInterface(ctrl)
+		mockRepository.EXPECT().
+			FindByKey("/path/to/token-cache", tokenCacheKey).
+			Return(nil, errors.New("file not found"))
+		mockRepository.EXPECT().
+			Save("/path/to/token-cache", tokenCacheKey, issuedTokenSet)
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().Write(issuedOutput)
+		u := GetToken{
+			Authentication:       mockAuthentication,
+			TokenCacheRepository: mockRepository,
+			Writer:               mockWriter,
+			Mutex:                mock_mutex.NewMockInterface(ctrl),
 			Logger:               logger.New(t),
 		}
 		if err := u.Do(ctx, in); err != nil {
@@ -160,50 +194,36 @@ func TestGetToken_Do(t *testing.T) {
 		defer ctrl.Finish()
 		ctx := context.TODO()
 		in := Input{
-			IssuerURL:     "https://accounts.google.com",
-			ClientID:      "YOUR_CLIENT_ID",
-			ClientSecret:  "YOUR_CLIENT_SECRET",
-			TokenCacheDir: "/path/to/token-cache",
+			Provider:       dummyProvider,
+			TokenCacheDir:  "/path/to/token-cache",
+			GrantOptionSet: grantOptionSet,
 		}
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		mockAuthentication.EXPECT().
 			Do(ctx, authentication.Input{
-				Provider: oidc.Provider{
-					IssuerURL:    "https://accounts.google.com",
-					ClientID:     "YOUR_CLIENT_ID",
-					ClientSecret: "YOUR_CLIENT_SECRET",
-				},
-				CachedTokenSet: &oidc.TokenSet{
-					IDToken: issuedIDToken,
-				},
+				Provider:       dummyProvider,
+				CachedTokenSet: &issuedTokenSet,
+				GrantOptionSet: grantOptionSet,
 			}).
 			Return(&authentication.Output{
 				AlreadyHasValidIDToken: true,
-				TokenSet: oidc.TokenSet{
-					IDToken: issuedIDToken,
-				},
+				TokenSet:               issuedTokenSet,
 			}, nil)
-		tokenCacheRepository := mock_tokencache.NewMockInterface(ctrl)
-		tokenCacheRepository.EXPECT().
+		mockRepository := mock_repository.NewMockInterface(ctrl)
+		mockRepository.EXPECT().
 			FindByKey("/path/to/token-cache", tokencache.Key{
 				IssuerURL:    "https://accounts.google.com",
 				ClientID:     "YOUR_CLIENT_ID",
 				ClientSecret: "YOUR_CLIENT_SECRET",
 			}).
-			Return(&oidc.TokenSet{
-				IDToken: issuedIDToken,
-			}, nil)
-		credentialPluginWriter := mock_credentialpluginwriter.NewMockInterface(ctrl)
-		credentialPluginWriter.EXPECT().
-			Write(credentialpluginwriter.Output{
-				Token:  issuedIDToken,
-				Expiry: issuedIDTokenExpiration,
-			})
+			Return(&issuedTokenSet, nil)
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().Write(issuedOutput)
 		u := GetToken{
 			Authentication:       mockAuthentication,
-			TokenCacheRepository: tokenCacheRepository,
-			Writer:               credentialPluginWriter,
-			Mutex:                setupMutexMock(ctrl),
+			TokenCacheRepository: mockRepository,
+			Writer:               mockWriter,
+			Mutex:                mock_mutex.NewMockInterface(ctrl),
 			Logger:               logger.New(t),
 		}
 		if err := u.Do(ctx, in); err != nil {
@@ -216,34 +236,30 @@ func TestGetToken_Do(t *testing.T) {
 		defer ctrl.Finish()
 		ctx := context.TODO()
 		in := Input{
-			IssuerURL:     "https://accounts.google.com",
-			ClientID:      "YOUR_CLIENT_ID",
-			ClientSecret:  "YOUR_CLIENT_SECRET",
-			TokenCacheDir: "/path/to/token-cache",
+			Provider:       dummyProvider,
+			TokenCacheDir:  "/path/to/token-cache",
+			GrantOptionSet: grantOptionSet,
 		}
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		mockAuthentication.EXPECT().
 			Do(ctx, authentication.Input{
-				Provider: oidc.Provider{
-					IssuerURL:    "https://accounts.google.com",
-					ClientID:     "YOUR_CLIENT_ID",
-					ClientSecret: "YOUR_CLIENT_SECRET",
-				},
+				Provider:       dummyProvider,
+				GrantOptionSet: grantOptionSet,
 			}).
-			Return(nil, xerrors.New("authentication error"))
-		tokenCacheRepository := mock_tokencache.NewMockInterface(ctrl)
-		tokenCacheRepository.EXPECT().
+			Return(nil, errors.New("authentication error"))
+		mockRepository := mock_repository.NewMockInterface(ctrl)
+		mockRepository.EXPECT().
 			FindByKey("/path/to/token-cache", tokencache.Key{
 				IssuerURL:    "https://accounts.google.com",
 				ClientID:     "YOUR_CLIENT_ID",
 				ClientSecret: "YOUR_CLIENT_SECRET",
 			}).
-			Return(nil, xerrors.New("file not found"))
+			Return(nil, errors.New("file not found"))
 		u := GetToken{
 			Authentication:       mockAuthentication,
-			TokenCacheRepository: tokenCacheRepository,
-			Writer:               mock_credentialpluginwriter.NewMockInterface(ctrl),
-			Mutex:                setupMutexMock(ctrl),
+			TokenCacheRepository: mockRepository,
+			Writer:               mock_writer.NewMockInterface(ctrl),
+			Mutex:                mock_mutex.NewMockInterface(ctrl),
 			Logger:               logger.New(t),
 		}
 		if err := u.Do(ctx, in); err == nil {
@@ -251,12 +267,3 @@ func TestGetToken_Do(t *testing.T) {
 		}
 	})
 }
-
-// Setup a mock that expect the mutex to be lock and unlock
-func setupMutexMock(ctrl *gomock.Controller) *mock_mutex.MockInterface {
-	mockMutex := mock_mutex.NewMockInterface(ctrl)
-	lockValue := &mutex.Lock{Data: "testData"}
-	acquireCall := mockMutex.EXPECT().Acquire(gomock.Not(gomock.Nil()), "get-token").Return(lockValue, nil)
-	mockMutex.EXPECT().Release(lockValue).Return(nil).After(acquireCall)
-	return mockMutex
-}

pkg/usecases/setup/setup.go

@@ -5,7 +5,7 @@ import (
 	"context"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
 )
 

pkg/usecases/setup/stage2.go

@@ -2,6 +2,7 @@ package setup
 
 import (
 	"context"
+	"fmt"
 	"path/filepath"
 	"strings"
 	"text/template"
@@ -9,7 +10,6 @@ import (
 	"github.com/int128/kubelogin/pkg/oidc"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
-	"golang.org/x/xerrors"
 )
 
 var stage2Tpl = template.Must(template.New("").Parse(`
@@ -73,6 +73,7 @@ type Stage2Input struct {
 	ClientID          string
 	ClientSecret      string
 	ExtraScopes       []string // optional
+	UsePKCE           bool     // optional
 	ListenAddressArgs []string // non-nil if set by the command arg
 	GrantOptionSet    authentication.GrantOptionSet
 	TLSClientConfig   tlsclientconfig.Config
@@ -86,16 +87,17 @@ func (u *Setup) DoStage2(ctx context.Context, in Stage2Input) error {
 			ClientID:     in.ClientID,
 			ClientSecret: in.ClientSecret,
 			ExtraScopes:  in.ExtraScopes,
+			UsePKCE:      in.UsePKCE,
 		},
 		GrantOptionSet:  in.GrantOptionSet,
 		TLSClientConfig: in.TLSClientConfig,
 	})
 	if err != nil {
-		return xerrors.Errorf("authentication error: %w", err)
+		return fmt.Errorf("authentication error: %w", err)
 	}
 	idTokenClaims, err := out.TokenSet.DecodeWithoutVerify()
 	if err != nil {
-		return xerrors.Errorf("you got an invalid token: %w", err)
+		return fmt.Errorf("you got an invalid token: %w", err)
 	}
 
 	v := stage2Vars{
@@ -107,7 +109,7 @@ func (u *Setup) DoStage2(ctx context.Context, in Stage2Input) error {
 	}
 	var b strings.Builder
 	if err := stage2Tpl.Execute(&b, &v); err != nil {
-		return xerrors.Errorf("could not render the template: %w", err)
+		return fmt.Errorf("could not render the template: %w", err)
 	}
 	u.Logger.Printf(b.String())
 	return nil
@@ -123,6 +125,9 @@ func makeCredentialPluginArgs(in Stage2Input) []string {
 	for _, extraScope := range in.ExtraScopes {
 		args = append(args, "--oidc-extra-scope="+extraScope)
 	}
+	if in.UsePKCE {
+		args = append(args, "--oidc-use-pkce")
+	}
 	for _, f := range in.TLSClientConfig.CACertFilename {
 		args = append(args, "--certificate-authority="+f)
 	}
@@ -137,6 +142,9 @@ func makeCredentialPluginArgs(in Stage2Input) []string {
 		if in.GrantOptionSet.AuthCodeBrowserOption.SkipOpenBrowser {
 			args = append(args, "--skip-open-browser")
 		}
+		if in.GrantOptionSet.AuthCodeBrowserOption.BrowserCommand != "" {
+			args = append(args, "--browser-command="+in.GrantOptionSet.AuthCodeBrowserOption.BrowserCommand)
+		}
 		if in.GrantOptionSet.AuthCodeBrowserOption.LocalServerCertFile != "" {
 			// Resolve the absolute path for the cert files so the user doesn't have to know
 			// to use one when running setup.

pkg/usecases/standalone/mock_standalone/mock_standalone.go

@@ -11,30 +11,30 @@ import (
 	reflect "reflect"
 )
 
-// MockInterface is a mock of Interface interface.
+// MockInterface is a mock of Interface interface
 type MockInterface struct {
 	ctrl     *gomock.Controller
 	recorder *MockInterfaceMockRecorder
 }
 
-// MockInterfaceMockRecorder is the mock recorder for MockInterface.
+// MockInterfaceMockRecorder is the mock recorder for MockInterface
 type MockInterfaceMockRecorder struct {
 	mock *MockInterface
 }
 
-// NewMockInterface creates a new mock instance.
+// NewMockInterface creates a new mock instance
 func NewMockInterface(ctrl *gomock.Controller) *MockInterface {
 	mock := &MockInterface{ctrl: ctrl}
 	mock.recorder = &MockInterfaceMockRecorder{mock}
 	return mock
 }
 
-// EXPECT returns an object that allows the caller to indicate expected use.
+// EXPECT returns an object that allows the caller to indicate expected use
 func (m *MockInterface) EXPECT() *MockInterfaceMockRecorder {
 	return m.recorder
 }
 
-// Do mocks base method.
+// Do mocks base method
 func (m *MockInterface) Do(arg0 context.Context, arg1 standalone.Input) error {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Do", arg0, arg1)
@@ -42,7 +42,7 @@ func (m *MockInterface) Do(arg0 context.Context, arg1 standalone.Input) error {
 	return ret0
 }
 
-// Do indicates an expected call of Do.
+// Do indicates an expected call of Do
 func (mr *MockInterfaceMockRecorder) Do(arg0, arg1 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Do", reflect.TypeOf((*MockInterface)(nil).Do), arg0, arg1)

pkg/usecases/standalone/standalone.go

@@ -2,14 +2,16 @@ package standalone
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/google/wire"
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
-	"github.com/int128/kubelogin/pkg/adaptors/logger"
+	"github.com/int128/kubelogin/pkg/infrastructure/logger"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
+	"github.com/int128/kubelogin/pkg/kubeconfig/loader"
+	"github.com/int128/kubelogin/pkg/kubeconfig/writer"
 	"github.com/int128/kubelogin/pkg/oidc"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
-	"golang.org/x/xerrors"
 )
 
 //go:generate mockgen -destination mock_standalone/mock_standalone.go github.com/int128/kubelogin/pkg/usecases/standalone Interface
@@ -42,11 +44,6 @@ To show the setup instruction:
 See https://github.com/int128/kubelogin for more.
 `
 
-const deprecationMessage = `NOTE: You can use the credential plugin mode for better user experience.
-Kubectl automatically runs kubelogin and you do not need to run kubelogin explicitly.
-See https://github.com/int128/kubelogin for more.
-`
-
 // Standalone provides the use case of explicit login.
 //
 // If the current auth provider is not oidc, show the error.
@@ -54,20 +51,20 @@ See https://github.com/int128/kubelogin for more.
 // Otherwise, update the kubeconfig.
 //
 type Standalone struct {
-	Authentication authentication.Interface
-	Kubeconfig     kubeconfig.Interface
-	Logger         logger.Interface
+	Authentication   authentication.Interface
+	KubeconfigLoader loader.Interface
+	KubeconfigWriter writer.Interface
+	Logger           logger.Interface
 }
 
 func (u *Standalone) Do(ctx context.Context, in Input) error {
 	u.Logger.V(1).Infof("WARNING: log may contain your secrets such as token or password")
 
-	authProvider, err := u.Kubeconfig.GetCurrentAuthProvider(in.KubeconfigFilename, in.KubeconfigContext, in.KubeconfigUser)
+	authProvider, err := u.KubeconfigLoader.GetCurrentAuthProvider(in.KubeconfigFilename, in.KubeconfigContext, in.KubeconfigUser)
 	if err != nil {
 		u.Logger.Printf(oidcConfigErrorMessage)
-		return xerrors.Errorf("could not find the current authentication provider: %w", err)
+		return fmt.Errorf("could not find the current authentication provider: %w", err)
 	}
-	u.Logger.Printf(deprecationMessage)
 	u.Logger.V(1).Infof("using the authentication provider of the user %s", authProvider.UserName)
 	u.Logger.V(1).Infof("a token will be written to %s", authProvider.LocationOfOrigin)
 	if authProvider.IDPCertificateAuthority != "" {
@@ -99,12 +96,12 @@ func (u *Standalone) Do(ctx context.Context, in Input) error {
 	}
 	authenticationOutput, err := u.Authentication.Do(ctx, authenticationInput)
 	if err != nil {
-		return xerrors.Errorf("authentication error: %w", err)
+		return fmt.Errorf("authentication error: %w", err)
 	}
 
 	idTokenClaims, err := authenticationOutput.TokenSet.DecodeWithoutVerify()
 	if err != nil {
-		return xerrors.Errorf("you got an invalid token: %w", err)
+		return fmt.Errorf("you got an invalid token: %w", err)
 	}
 	u.Logger.V(1).Infof("you got a token: %s", idTokenClaims.Pretty)
 	if authenticationOutput.AlreadyHasValidIDToken {
@@ -116,8 +113,8 @@ func (u *Standalone) Do(ctx context.Context, in Input) error {
 	authProvider.IDToken = authenticationOutput.TokenSet.IDToken
 	authProvider.RefreshToken = authenticationOutput.TokenSet.RefreshToken
 	u.Logger.V(1).Infof("writing the ID token and refresh token to %s", authProvider.LocationOfOrigin)
-	if err := u.Kubeconfig.UpdateAuthProvider(authProvider); err != nil {
-		return xerrors.Errorf("could not update the kubeconfig: %w", err)
+	if err := u.KubeconfigWriter.UpdateAuthProvider(*authProvider); err != nil {
+		return fmt.Errorf("could not update the kubeconfig: %w", err)
 	}
 	return nil
 }

pkg/usecases/standalone/standalone_test.go

@@ -2,19 +2,20 @@ package standalone
 
 import (
 	"context"
+	"errors"
 	"testing"
 	"time"
 
 	"github.com/golang/mock/gomock"
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig"
-	"github.com/int128/kubelogin/pkg/adaptors/kubeconfig/mock_kubeconfig"
+	"github.com/int128/kubelogin/pkg/kubeconfig"
+	"github.com/int128/kubelogin/pkg/kubeconfig/loader/mock_loader"
+	"github.com/int128/kubelogin/pkg/kubeconfig/writer/mock_writer"
 	"github.com/int128/kubelogin/pkg/oidc"
 	testingJWT "github.com/int128/kubelogin/pkg/testing/jwt"
 	"github.com/int128/kubelogin/pkg/testing/logger"
 	"github.com/int128/kubelogin/pkg/tlsclientconfig"
 	"github.com/int128/kubelogin/pkg/usecases/authentication"
 	"github.com/int128/kubelogin/pkg/usecases/authentication/mock_authentication"
-	"golang.org/x/xerrors"
 )
 
 func TestStandalone_Do(t *testing.T) {
@@ -45,12 +46,13 @@ func TestStandalone_Do(t *testing.T) {
 			IDPCertificateAuthority:     "/path/to/cert2",
 			IDPCertificateAuthorityData: "BASE64ENCODED2",
 		}
-		mockKubeconfig := mock_kubeconfig.NewMockInterface(ctrl)
-		mockKubeconfig.EXPECT().
+		mockLoader := mock_loader.NewMockInterface(ctrl)
+		mockLoader.EXPECT().
 			GetCurrentAuthProvider("/path/to/kubeconfig", kubeconfig.ContextName("theContext"), kubeconfig.UserName("theUser")).
 			Return(currentAuthProvider, nil)
-		mockKubeconfig.EXPECT().
-			UpdateAuthProvider(&kubeconfig.AuthProvider{
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().
+			UpdateAuthProvider(kubeconfig.AuthProvider{
 				LocationOfOrigin:            "/path/to/kubeconfig",
 				UserName:                    "theUser",
 				IDPIssuerURL:                "https://accounts.google.com",
@@ -82,9 +84,10 @@ func TestStandalone_Do(t *testing.T) {
 				},
 			}, nil)
 		u := Standalone{
-			Authentication: mockAuthentication,
-			Kubeconfig:     mockKubeconfig,
-			Logger:         logger.New(t),
+			Authentication:   mockAuthentication,
+			KubeconfigLoader: mockLoader,
+			KubeconfigWriter: mockWriter,
+			Logger:           logger.New(t),
 		}
 		if err := u.Do(ctx, in); err != nil {
 			t.Errorf("Do returned error: %+v", err)
@@ -104,8 +107,8 @@ func TestStandalone_Do(t *testing.T) {
 			ClientSecret:     "YOUR_CLIENT_SECRET",
 			IDToken:          issuedIDToken,
 		}
-		mockKubeconfig := mock_kubeconfig.NewMockInterface(ctrl)
-		mockKubeconfig.EXPECT().
+		mockLoader := mock_loader.NewMockInterface(ctrl)
+		mockLoader.EXPECT().
 			GetCurrentAuthProvider("", kubeconfig.ContextName(""), kubeconfig.UserName("")).
 			Return(currentAuthProvider, nil)
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
@@ -127,9 +130,9 @@ func TestStandalone_Do(t *testing.T) {
 				},
 			}, nil)
 		u := Standalone{
-			Authentication: mockAuthentication,
-			Kubeconfig:     mockKubeconfig,
-			Logger:         logger.New(t),
+			Authentication:   mockAuthentication,
+			KubeconfigLoader: mockLoader,
+			Logger:           logger.New(t),
 		}
 		if err := u.Do(ctx, in); err != nil {
 			t.Errorf("Do returned error: %+v", err)
@@ -141,15 +144,15 @@ func TestStandalone_Do(t *testing.T) {
 		defer ctrl.Finish()
 		ctx := context.TODO()
 		in := Input{}
-		mockKubeconfig := mock_kubeconfig.NewMockInterface(ctrl)
-		mockKubeconfig.EXPECT().
+		mockLoader := mock_loader.NewMockInterface(ctrl)
+		mockLoader.EXPECT().
 			GetCurrentAuthProvider("", kubeconfig.ContextName(""), kubeconfig.UserName("")).
-			Return(nil, xerrors.New("no oidc config"))
+			Return(nil, errors.New("no oidc config"))
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		u := Standalone{
-			Authentication: mockAuthentication,
-			Kubeconfig:     mockKubeconfig,
-			Logger:         logger.New(t),
+			Authentication:   mockAuthentication,
+			KubeconfigLoader: mockLoader,
+			Logger:           logger.New(t),
 		}
 		if err := u.Do(ctx, in); err == nil {
 			t.Errorf("err wants non-nil but nil")
@@ -168,8 +171,8 @@ func TestStandalone_Do(t *testing.T) {
 			ClientID:         "YOUR_CLIENT_ID",
 			ClientSecret:     "YOUR_CLIENT_SECRET",
 		}
-		mockKubeconfig := mock_kubeconfig.NewMockInterface(ctrl)
-		mockKubeconfig.EXPECT().
+		mockLoader := mock_loader.NewMockInterface(ctrl)
+		mockLoader.EXPECT().
 			GetCurrentAuthProvider("", kubeconfig.ContextName(""), kubeconfig.UserName("")).
 			Return(currentAuthProvider, nil)
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
@@ -181,11 +184,11 @@ func TestStandalone_Do(t *testing.T) {
 					ClientSecret: "YOUR_CLIENT_SECRET",
 				},
 			}).
-			Return(nil, xerrors.New("authentication error"))
+			Return(nil, errors.New("authentication error"))
 		u := Standalone{
-			Authentication: mockAuthentication,
-			Kubeconfig:     mockKubeconfig,
-			Logger:         logger.New(t),
+			Authentication:   mockAuthentication,
+			KubeconfigLoader: mockLoader,
+			Logger:           logger.New(t),
 		}
 		if err := u.Do(ctx, in); err == nil {
 			t.Errorf("err wants non-nil but nil")
@@ -204,12 +207,13 @@ func TestStandalone_Do(t *testing.T) {
 			ClientID:         "YOUR_CLIENT_ID",
 			ClientSecret:     "YOUR_CLIENT_SECRET",
 		}
-		mockKubeconfig := mock_kubeconfig.NewMockInterface(ctrl)
-		mockKubeconfig.EXPECT().
+		mockLoader := mock_loader.NewMockInterface(ctrl)
+		mockLoader.EXPECT().
 			GetCurrentAuthProvider("", kubeconfig.ContextName(""), kubeconfig.UserName("")).
 			Return(currentAuthProvider, nil)
-		mockKubeconfig.EXPECT().
-			UpdateAuthProvider(&kubeconfig.AuthProvider{
+		mockWriter := mock_writer.NewMockInterface(ctrl)
+		mockWriter.EXPECT().
+			UpdateAuthProvider(kubeconfig.AuthProvider{
 				LocationOfOrigin: "/path/to/kubeconfig",
 				UserName:         "google",
 				IDPIssuerURL:     "https://accounts.google.com",
@@ -218,7 +222,7 @@ func TestStandalone_Do(t *testing.T) {
 				IDToken:          issuedIDToken,
 				RefreshToken:     "YOUR_REFRESH_TOKEN",
 			}).
-			Return(xerrors.New("I/O error"))
+			Return(errors.New("I/O error"))
 		mockAuthentication := mock_authentication.NewMockInterface(ctrl)
 		mockAuthentication.EXPECT().
 			Do(ctx, authentication.Input{
@@ -235,9 +239,10 @@ func TestStandalone_Do(t *testing.T) {
 				},
 			}, nil)
 		u := Standalone{
-			Authentication: mockAuthentication,
-			Kubeconfig:     mockKubeconfig,
-			Logger:         logger.New(t),
+			Authentication:   mockAuthentication,
+			KubeconfigLoader: mockLoader,
+			KubeconfigWriter: mockWriter,
+			Logger:           logger.New(t),
 		}
 		if err := u.Do(ctx, in); err == nil {
 			t.Errorf("err wants non-nil but nil")

system_test/login/Makefile

@@ -7,10 +7,6 @@ export PATH
 KUBECONFIG := ../cluster/kubeconfig.yaml
 export KUBECONFIG
 
-# run the login script instead of opening chrome
-BROWSER := $(BIN_DIR)/chromelogin
-export BROWSER
-
 .PHONY: test
 test: build
 	# see the setup instruction
@@ -19,7 +15,8 @@ test: build
 		--oidc-client-id=YOUR_CLIENT_ID \
 		--oidc-client-secret=YOUR_CLIENT_SECRET \
 		--oidc-extra-scope=email \
-		--certificate-authority=$(CERT_DIR)/ca.crt
+		--certificate-authority=$(CERT_DIR)/ca.crt \
+		--browser-command=$(BIN_DIR)/chromelogin
 	# set up the kubeconfig
 	kubectl config set-credentials oidc \
 		--exec-api-version=client.authentication.k8s.io/v1beta1 \
@@ -30,7 +27,8 @@ test: build
 		--exec-arg=--oidc-client-id=YOUR_CLIENT_ID \
 		--exec-arg=--oidc-client-secret=YOUR_CLIENT_SECRET \
 		--exec-arg=--oidc-extra-scope=email \
-		--exec-arg=--certificate-authority=$(CERT_DIR)/ca.crt
+		--exec-arg=--certificate-authority=$(CERT_DIR)/ca.crt \
+		--exec-arg=--browser-command=$(BIN_DIR)/chromelogin
 	# make sure we can access the cluster
 	kubectl --user=oidc cluster-info
 	# switch the current context