Add support of HTTP_PROXY, HTTPS_PROXY and NO_PROXY (#51)

Add yaml for Krew installation

.circleci/config.yml

@@ -2,39 +2,36 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/golang:1.10
-    working_directory: /go/src/github.com/int128/kubelogin
+      - image: circleci/golang:1.11.1
     steps:
+      - run: |
+          mkdir -p ~/bin
+          echo 'export PATH="$HOME/bin:$PATH"' >> $BASH_ENV
+      - run: |
+          curl -L -o ~/bin/kubectl https://storage.googleapis.com/kubernetes-release/release/v1.14.0/bin/linux/amd64/kubectl
+          chmod +x ~/bin/kubectl
+      - run: |
+          go get -v \
+            golang.org/x/lint/golint \
+            github.com/int128/goxzst \
+            github.com/tcnksm/ghr \
+            github.com/int128/ghcp
       - checkout
-      - run: go get -v -t -d ./...
-      - run: go get github.com/golang/lint/golint
-      - run: golint
-      - run: go build -v
-      - run: make -C e2e/authserver/testdata
-      - run: go test -v ./...
-
-  release:
-    docker:
-      - image: circleci/golang:1.10
-    working_directory: /go/src/github.com/int128/kubelogin
-    steps:
-      - checkout
-      - run: go get -v -t -d ./...
-      - run: curl -sL https://git.io/goreleaser | bash
+      # workaround for https://github.com/golang/go/issues/27925
+      - run: sed -e '/^k8s.io\/client-go /d' -i go.sum
+      - run: make check
+      - run: make run
+      - run: |
+          if [ "$CIRCLE_TAG" ]; then
+            make release
+          fi
 
 workflows:
   version: 2
   all:
     jobs:
       - build:
+          context: open-source
           filters:
             tags:
               only: /.*/
-      - release:
-          filters:
-            branches:
-              ignore: /.*/
-            tags:
-              only: /.*/
-          requires:
-            - build

.editorconfig

@@ -1,15 +0,0 @@
-root = true
-
-[*]
-end_of_line = lf
-insert_final_newline = true
-indent_style = space
-indent_size = 2
-
-[*.go]
-indent_style = tab
-indent_size = 4
-
-[Makefile]
-indent_style = tab
-indent_size = 4

.gitignore

@@ -1,2 +1,5 @@
+/.idea
 /dist
+/kubelogin
+/kubectl-oidc_login
 /.kubeconfig

.goreleaser.yml

@@ -1,19 +0,0 @@
-builds:
-  - binary: kubelogin
-    goos:
-      - windows
-      - darwin
-      - linux
-    goarch:
-      - amd64
-archive:
-  files:
-    - none*
-brew:
-  github:
-    owner: int128
-    name: homebrew-kubelogin
-  homepage: https://github.com/int128/kubelogin
-  description: "kubectl with OpenID Connect (OIDC) authentication"
-  test: system "#{bin}/kubelogin --help"
-  install: bin.install "kubelogin"

Makefile

@@ -0,0 +1,36 @@
+TARGET := kubelogin
+TARGET_PLUGIN := kubectl-oidc_login
+CIRCLE_TAG ?= HEAD
+LDFLAGS := -X main.version=$(CIRCLE_TAG)
+
+.PHONY: check run release clean
+
+all: $(TARGET)
+
+check:
+	golint
+	go vet
+	$(MAKE) -C adaptors_test/authserver/testdata
+	go test -v ./...
+
+$(TARGET): $(wildcard *.go)
+	go build -o $@ -ldflags "$(LDFLAGS)"
+
+$(TARGET_PLUGIN): $(TARGET)
+	ln -sf $(TARGET) $@
+
+run: $(TARGET_PLUGIN)
+	-PATH=.:$(PATH) kubectl oidc-login --help
+
+dist:
+	VERSION=$(CIRCLE_TAG) goxzst -d dist/gh/ -o "$(TARGET)" -t "kubelogin.rb oidc-login.yaml" -- -ldflags "$(LDFLAGS)"
+	mv dist/gh/kubelogin.rb dist/
+
+release: dist
+	ghr -u "$(CIRCLE_PROJECT_USERNAME)" -r "$(CIRCLE_PROJECT_REPONAME)" "$(CIRCLE_TAG)" dist/gh/
+	ghcp -u "$(CIRCLE_PROJECT_USERNAME)" -r "homebrew-$(CIRCLE_PROJECT_REPONAME)" -m "$(CIRCLE_TAG)" -C dist/ kubelogin.rb
+
+clean:
+	-rm $(TARGET)
+	-rm $(TARGET_PLUGIN)
+	-rm -r dist/

README.md

@@ -1,195 +1,72 @@
 # kubelogin [![CircleCI](https://circleci.com/gh/int128/kubelogin.svg?style=shield)](https://circleci.com/gh/int128/kubelogin)
 
-This is a command for [Kubernetes OpenID Connect (OIDC) authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
+This is a kubectl plugin for [Kubernetes OpenID Connect (OIDC) authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
 It gets a token from the OIDC provider and writes it to the kubeconfig.
 
-This may work with various OIDC providers such as Keycloak, Google Identity Platform and Azure AD.
 
+## Getting Started
 
-## TL;DR
+You need to setup the following components:
 
-You need to setup the OIDC provider and [Kubernetes OIDC authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
+- OIDC provider
+- Kubernetes API server
+- Role for your group or user
+- kubectl authentication
 
-After initial setup or when the token has been expired, just run `kubelogin`:
+You can install [the latest release](https://github.com/int128/kubelogin/releases) by the following ways:
+
+```sh
+# Homebrew
+brew tap int128/kubelogin
+brew install kubelogin
+
+# Krew (experimental)
+curl -LO https://github.com/int128/kubelogin/releases/download/v1.9.0/oidc-login.yaml
+kubectl krew install --manifest oidc-login.yaml
+
+# GitHub Releases
+curl -LO https://github.com/int128/kubelogin/releases/download/v1.9.0/kubelogin_linux_amd64.zip
+unzip kubelogin_linux_amd64.zip
+ln -s kubelogin kubectl-oidc_login
+```
+
+After initial setup or when the token has been expired, just run:
 
 ```
 % kubelogin
 2018/08/27 15:03:06 Reading /home/user/.kube/config
 2018/08/27 15:03:06 Using current context: hello.k8s.local
 2018/08/27 15:03:07 Open http://localhost:8000 for authorization
-```
-
-It opens the browser and you can log in to the provider.
-After you logged in to the provider, it closes the browser automatically.
-
-Then it writes the ID token and refresh token to the kubeconfig.
-
-```
-2018/08/27 15:03:07 GET /
-2018/08/27 15:03:08 GET /?state=a51081925f20c043&session_state=5637cbdf-ffdc-4fab-9fc7-68a3e6f2e73f&code=ey...
 2018/08/27 15:03:09 Got token for subject=cf228a73-47fe-4986-a2a8-b2ced80a884b
 2018/08/27 15:03:09 Updated /home/user/.kube/config
 ```
 
-Please see the later section for details.
-
-
-## Getting Started with Google Account
-
-### 1. Setup Google API
-
-Open [Google APIs Console](https://console.developers.google.com/apis/credentials) and create an OAuth client as follows:
-
-- Application Type: Web application
-- Redirect URL: `http://localhost:8000/`
-
-### 2. Setup Kubernetes cluster
-
-Configure your Kubernetes API Server accepts [OpenID Connect Tokens](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
-If you are using [kops](https://github.com/kubernetes/kops), run `kops edit cluster` and append the following settings:
-
-```yaml
-spec:
-  kubeAPIServer:
-    oidcIssuerURL: https://accounts.google.com
-    oidcClientID: YOUR_CLIENT_ID.apps.googleusercontent.com
-```
-
-Here assign the `cluster-admin` role to your user.
-
-```yaml
-kind: ClusterRoleBinding
-apiVersion: rbac.authorization.k8s.io/v1
-metadata:
-  name: oidc-admin-group
-roleRef:
-  apiGroup: rbac.authorization.k8s.io
-  kind: ClusterRole
-  name: cluster-admin
-subjects:
-- kind: User
-  name: https://accounts.google.com#1234567890
-```
-
-### 3. Setup kubectl and kubelogin
-
-Setup `kubectl` to authenticate with your identity provider.
-
-```sh
-kubectl config set-credentials NAME \
-  --auth-provider oidc \
-  --auth-provider-arg idp-issuer-url=https://accounts.google.com \
-  --auth-provider-arg client-id=YOUR_CLIENT_ID.apps.googleusercontent.com \
-  --auth-provider-arg client-secret=YOUR_CLIENT_SECRET
-```
-
-Download [the latest release](https://github.com/int128/kubelogin/releases) and save it.
-
-Run `kubelogin` and open http://localhost:8000 in your browser.
+or run as a kubectl plugin:
 
 ```
-% kubelogin
-2018/08/10 10:36:38 Reading .kubeconfig
-2018/08/10 10:36:38 Using current context: hello.k8s.local
-2018/08/10 10:36:41 Open http://localhost:8000 for authorization
-2018/08/10 10:36:45 GET /
-2018/08/10 10:37:07 GET /?state=...&session_state=...&code=ey...
-2018/08/10 10:37:08 Updated .kubeconfig
+% kubectl oidc-login
 ```
 
-Now your `~/.kube/config` should be like:
+It opens the browser and you can log in to the provider.
+After authentication, it gets an ID token and refresh token and writes them to the kubeconfig.
 
-```yaml
-users:
-- name: hello.k8s.local
-  user:
-    auth-provider:
-      config:
-        idp-issuer-url: https://accounts.google.com
-        client-id: YOUR_CLIENT_ID.apps.googleusercontent.com
-        client-secret: YOUR_SECRET
-        id-token: ey...       # kubelogin will update ID token here
-        refresh-token: ey...  # kubelogin will update refresh token here
-      name: oidc
-```
+For more, see the following documents:
 
-Make sure you can access to the Kubernetes cluster.
-
-```
-% kubectl get nodes
-NAME                                    STATUS    ROLES     AGE       VERSION
-ip-1-2-3-4.us-west-2.compute.internal   Ready     node      21d       v1.9.6
-ip-1-2-3-5.us-west-2.compute.internal   Ready     node      20d       v1.9.6
-```
-
-
-## Getting Started with Keycloak
-
-### 1. Setup Keycloak
-
-Create an OIDC client as follows:
-
-- Redirect URL: `http://localhost:8000/`
-- Issuer URL: `https://keycloak.example.com/auth/realms/YOUR_REALM`
-- Client ID: `kubernetes`
-- Groups claim: `groups`
-
-Then create a group `kubernetes:admin` and join to it.
-
-### 2. Setup Kubernetes cluster
-
-Configure your Kubernetes API Server accepts [OpenID Connect Tokens](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
-If you are using [kops](https://github.com/kubernetes/kops), run `kops edit cluster` and append the following settings:
-
-```yaml
-spec:
-  kubeAPIServer:
-    oidcIssuerURL: https://keycloak.example.com/auth/realms/YOUR_REALM
-    oidcClientID: kubernetes
-    oidcGroupsClaim: groups
-```
-
-Here assign the `cluster-admin` role to the `kubernetes:admin` group.
-
-```yaml
-kind: ClusterRoleBinding
-apiVersion: rbac.authorization.k8s.io/v1
-metadata:
-  name: keycloak-admin-group
-roleRef:
-  apiGroup: rbac.authorization.k8s.io
-  kind: ClusterRole
-  name: cluster-admin
-subjects:
-- kind: Group
-  name: /kubernetes:admin
-```
-
-### 3. Setup kubectl and kubelogin
-
-Setup `kubectl` to authenticate with your identity provider.
-
-```sh
-kubectl config set-credentials NAME \
-  --auth-provider oidc \
-  --auth-provider-arg idp-issuer-url=https://keycloak.example.com/auth/realms/YOUR_REALM \
-  --auth-provider-arg client-id=kubernetes \
-  --auth-provider-arg client-secret=YOUR_CLIENT_SECRET
-```
-
-Download [the latest release](https://github.com/int128/kubelogin/releases) and save it.
-
-Run `kubelogin` and make sure you can access to the cluster.
-See the previous section for details.
+- [Getting Started with Keycloak](docs/keycloak.md)
+- [Getting Started with Google Identity Platform](docs/google.md)
+- [Team Operation](docs/team_ops.md)
 
 
 ## Configuration
 
+This supports the following options.
+
 ```
   kubelogin [OPTIONS]
 
 Application Options:
       --kubeconfig=               Path to the kubeconfig file (default: ~/.kube/config) [$KUBECONFIG]
+      --listen-port=              Port used by kubelogin to bind its webserver (default: 8000) [$KUBELOGIN_LISTEN_PORT]
       --insecure-skip-tls-verify  If set, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure
                                   [$KUBELOGIN_INSECURE_SKIP_TLS_VERIFY]
       --skip-open-browser         If set, it does not open the browser on authentication. [$KUBELOGIN_SKIP_OPEN_BROWSER]
@@ -198,19 +75,19 @@ Help Options:
   -h, --help        Show this help message
 ```
 
-This supports the following keys of `auth-provider` in kubeconfig.
-See also [kubectl authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#using-kubectl).
+This also supports the following keys of `auth-provider` in kubeconfig.
+See [kubectl authentication](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#using-kubectl).
 
 Key | Direction | Value
 ----|-----------|------
-`idp-issuer-url`                  | IN (Required) | Issuer URL of the provider.
-`client-id`                       | IN (Required) | Client ID of the provider.
-`client-secret`                   | IN (Required) | Client Secret of the provider.
-`idp-certificate-authority`       | IN (Optional) | CA certificate path of the provider.
-`idp-certificate-authority-data`  | IN (Optional) | Base64 encoded CA certificate of the provider.
-`extra-scopes`                    | IN (Optional) | Scopes to request to the provider (comma separated).
-`id-token`                        | OUT | ID token got from the provider.
-`refresh-token`                   | OUT | Refresh token got from the provider.
+`idp-issuer-url`                  | Read (Mandatory) | Issuer URL of the provider.
+`client-id`                       | Read (Mandatory) | Client ID of the provider.
+`client-secret`                   | Read (Mandatory) | Client Secret of the provider.
+`idp-certificate-authority`       | Read | CA certificate path of the provider.
+`idp-certificate-authority-data`  | Read | Base64 encoded CA certificate of the provider.
+`extra-scopes`                    | Read | Scopes to request to the provider (comma separated).
+`id-token`                        | Write | ID token got from the provider.
+`refresh-token`                   | Write | Refresh token got from the provider.
 
 
 ### Kubeconfig path
@@ -222,62 +99,43 @@ Default to `~/.kube/config`.
 export KUBECONFIG="$PWD/.kubeconfig"
 ```
 
-### Team onboarding
 
-You can share the kubeconfig to your team members for easy setup.
+### Extra scopes
 
-```yaml
-apiVersion: v1
-kind: Config
-clusters:
-  - cluster:
-      certificate-authority-data: LS...
-      server: https://api.hello.k8s.example.com
-      name: hello.k8s.local
-contexts:
-- context:
-    cluster: hello.k8s.local
-    user: hello.k8s.local
-  name: hello.k8s.local
-current-context: hello.k8s.local
-preferences: {}
-users:
-- name: hello.k8s.local
-  user:
-    auth-provider:
-      name: oidc
-      config:
-        client-id: YOUR_CLIEND_ID
-        client-secret: YOUR_CLIENT_SECRET
-        idp-issuer-url: YOUR_ISSUER
-```
-
-If you are using kops, export the kubeconfig and edit it.
+You can set extra scopes to request to the provider by `extra-scopes` in the kubeconfig.
 
 ```sh
-KUBECONFIG=.kubeconfig kops export kubecfg hello.k8s.local
-vim .kubeconfig
+kubectl config set-credentials keycloak --auth-provider-arg extra-scopes=email
 ```
 
+Note that kubectl does not accept multiple scopes and 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/ $KUBECONFIG
+```
+
+
+### CA Certificates
+
+You can set your self-signed certificates for the OIDC provider (not Kubernetes API server) by `idp-certificate-authority` and `idp-certificate-authority-data` in the kubeconfig.
+
+```sh
+kubectl config set-credentials keycloak \
+  --auth-provider-arg idp-certificate-authority=$HOME/.kube/keycloak-ca.pem
+```
+
+If kubelogin could not parse the certificate, it shows a warning and skips it.
+
+
+### HTTP Proxy
+
+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).
+
 
 ## Contributions
 
 This is an open source software licensed under Apache License 2.0.
-Feel free to open issues and pull requests.
 
-### Build and Test
-
-```sh
-go get github.com/int128/kubelogin
-```
-
-```sh
-cd $GOPATH/src/github.com/int128/kubelogin
-make -C e2e/authserver/testdata
-go test -v ./...
-```
-
-### Release
-
-CircleCI publishes the build to GitHub.
-See [.circleci/config.yml](.circleci/config.yml).
+Feel free to open issues and pull requests for improving code and documents.

adaptors/cmd.go

@@ -0,0 +1,73 @@
+package adaptors
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/usecases/interfaces"
+	"github.com/jessevdk/go-flags"
+	"github.com/mitchellh/go-homedir"
+	"github.com/pkg/errors"
+	"go.uber.org/dig"
+)
+
+func NewCmd(i Cmd) adaptors.Cmd {
+	return &i
+}
+
+type Cmd struct {
+	dig.In
+	Login  usecases.Login
+	Logger adaptors.Logger
+}
+
+func (cmd *Cmd) Run(ctx context.Context, args []string, version string) int {
+	var o cmdOptions
+	parser := flags.NewParser(&o, flags.HelpFlag)
+	parser.LongDescription = fmt.Sprintf(`Version %s
+		This updates the kubeconfig for Kubernetes OpenID Connect (OIDC) authentication.`,
+		version)
+	args, err := parser.ParseArgs(args[1:])
+	if err != nil {
+		cmd.Logger.Logf("Error: %s", err)
+		return 1
+	}
+	if len(args) > 0 {
+		cmd.Logger.Logf("Error: too many arguments")
+		return 1
+	}
+	kubeConfig, err := o.ExpandKubeConfig()
+	if err != nil {
+		cmd.Logger.Logf("Error: invalid option: %s", err)
+		return 1
+	}
+
+	in := usecases.LoginIn{
+		KubeConfig:      kubeConfig,
+		ListenPort:      o.ListenPort,
+		SkipTLSVerify:   o.SkipTLSVerify,
+		SkipOpenBrowser: o.SkipOpenBrowser,
+	}
+	if err := cmd.Login.Do(ctx, in); err != nil {
+		cmd.Logger.Logf("Error: %s", err)
+		return 1
+	}
+	return 0
+}
+
+type cmdOptions struct {
+	KubeConfig      string `long:"kubeconfig" default:"~/.kube/config" env:"KUBECONFIG" description:"Path to the kubeconfig file"`
+	ListenPort      int    `long:"listen-port" default:"8000" env:"KUBELOGIN_LISTEN_PORT" description:"Port used by kubelogin to bind its webserver"`
+	SkipTLSVerify   bool   `long:"insecure-skip-tls-verify" env:"KUBELOGIN_INSECURE_SKIP_TLS_VERIFY" description:"If set, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure"`
+	SkipOpenBrowser bool   `long:"skip-open-browser" env:"KUBELOGIN_SKIP_OPEN_BROWSER" description:"If set, it does not open the browser on authentication."`
+}
+
+// ExpandKubeConfig returns an expanded KubeConfig path.
+func (c *cmdOptions) ExpandKubeConfig() (string, error) {
+	d, err := homedir.Expand(c.KubeConfig)
+	if err != nil {
+		return "", errors.Wrapf(err, "could not expand %s", c.KubeConfig)
+	}
+	return d, nil
+}

adaptors/cmd_test.go

@@ -0,0 +1,87 @@
+package adaptors
+
+import (
+	"context"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/int128/kubelogin/usecases/interfaces"
+	"github.com/int128/kubelogin/usecases/mock_usecases"
+	"github.com/mitchellh/go-homedir"
+)
+
+func TestCmd_Run(t *testing.T) {
+	const executable = "kubelogin"
+	const version = "HEAD"
+
+	t.Run("Defaults", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		login := mock_usecases.NewMockLogin(ctrl)
+		login.EXPECT().
+			Do(ctx, usecases.LoginIn{
+				KubeConfig: expand(t, "~/.kube/config"),
+				ListenPort: 8000,
+			})
+
+		cmd := Cmd{
+			Login:  login,
+			Logger: t,
+		}
+		exitCode := cmd.Run(ctx, []string{executable}, version)
+		if exitCode != 0 {
+			t.Errorf("exitCode wants 0 but %d", exitCode)
+		}
+	})
+
+	t.Run("FullOptions", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		login := mock_usecases.NewMockLogin(ctrl)
+		login.EXPECT().
+			Do(ctx, usecases.LoginIn{
+				KubeConfig:      expand(t, "~/.kube/config"),
+				ListenPort:      10080,
+				SkipTLSVerify:   true,
+				SkipOpenBrowser: true,
+			})
+
+		cmd := Cmd{
+			Login:  login,
+			Logger: t,
+		}
+		exitCode := cmd.Run(ctx, []string{executable,
+			"--listen-port", "10080",
+			"--insecure-skip-tls-verify",
+			"--skip-open-browser",
+		}, 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{
+			Login:  mock_usecases.NewMockLogin(ctrl),
+			Logger: t,
+		}
+		exitCode := cmd.Run(context.TODO(), []string{executable, "some"}, version)
+		if exitCode != 1 {
+			t.Errorf("exitCode wants 1 but %d", exitCode)
+		}
+	})
+}
+
+func expand(t *testing.T, path string) string {
+	d, err := homedir.Expand(path)
+	if err != nil {
+		t.Fatalf("could not expand: %s", err)
+	}
+	return d
+}

adaptors/http.go

@@ -0,0 +1,74 @@
+package adaptors
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/base64"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/pkg/errors"
+)
+
+func NewHTTP() adaptors.HTTP {
+	return &HTTP{}
+}
+
+type HTTP struct{}
+
+func (*HTTP) NewClientConfig() adaptors.HTTPClientConfig {
+	return &httpClientConfig{
+		certPool: x509.NewCertPool(),
+	}
+}
+
+func (*HTTP) NewClient(config adaptors.HTTPClientConfig) (*http.Client, error) {
+	return &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: config.TLSConfig(),
+			Proxy:           http.ProxyFromEnvironment,
+		},
+	}, nil
+}
+
+type httpClientConfig struct {
+	certPool      *x509.CertPool
+	skipTLSVerify bool
+}
+
+func (c *httpClientConfig) AddCertificateFromFile(filename string) error {
+	b, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return errors.Wrapf(err, "could not read %s", filename)
+	}
+	if c.certPool.AppendCertsFromPEM(b) != true {
+		return errors.Errorf("could not append certificate from %s", filename)
+	}
+	return nil
+}
+
+func (c *httpClientConfig) AddEncodedCertificate(base64String string) error {
+	b, err := base64.StdEncoding.DecodeString(base64String)
+	if err != nil {
+		return errors.Wrapf(err, "could not decode base64")
+	}
+	if c.certPool.AppendCertsFromPEM(b) != true {
+		return errors.Errorf("could not append certificate")
+	}
+	return nil
+}
+
+func (c *httpClientConfig) TLSConfig() *tls.Config {
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: c.skipTLSVerify,
+	}
+	if len(c.certPool.Subjects()) > 0 {
+		tlsConfig.RootCAs = c.certPool
+	}
+	return tlsConfig
+}
+
+func (c *httpClientConfig) SetSkipTLSVerify(b bool) {
+	c.skipTLSVerify = b
+}

adaptors/interfaces/adaptors.go

@@ -0,0 +1,58 @@
+package adaptors
+
+import (
+	"context"
+	"crypto/tls"
+	"net/http"
+
+	"github.com/coreos/go-oidc"
+	"k8s.io/client-go/tools/clientcmd/api"
+)
+
+//go:generate mockgen -package mock_adaptors -destination ../mock_adaptors/mock_adaptors.go github.com/int128/kubelogin/adaptors/interfaces KubeConfig,HTTP,HTTPClientConfig,OIDC
+
+type Cmd interface {
+	Run(ctx context.Context, args []string, version string) int
+}
+
+type KubeConfig interface {
+	LoadFromFile(filename string) (*api.Config, error)
+	WriteToFile(config *api.Config, filename string) error
+}
+
+type HTTP interface {
+	NewClientConfig() HTTPClientConfig
+	NewClient(config HTTPClientConfig) (*http.Client, error)
+}
+
+type HTTPClientConfig interface {
+	AddCertificateFromFile(filename string) error
+	AddEncodedCertificate(base64String string) error
+	SetSkipTLSVerify(b bool)
+
+	TLSConfig() *tls.Config
+}
+
+type OIDC interface {
+	Authenticate(ctx context.Context, in OIDCAuthenticateIn) (*OIDCAuthenticateOut, error)
+}
+
+type OIDCAuthenticateIn struct {
+	Issuer          string
+	ClientID        string
+	ClientSecret    string
+	ExtraScopes     []string     // Additional scopes
+	Client          *http.Client // HTTP client for oidc and oauth2
+	LocalServerPort int          // HTTP server port
+	SkipOpenBrowser bool         // skip opening browser if true
+}
+
+type OIDCAuthenticateOut struct {
+	VerifiedIDToken *oidc.IDToken
+	IDToken         string
+	RefreshToken    string
+}
+
+type Logger interface {
+	Logf(format string, v ...interface{})
+}

adaptors/kubeconfig.go

@@ -0,0 +1,30 @@
+package adaptors
+
+import (
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/pkg/errors"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/client-go/tools/clientcmd/api"
+)
+
+func NewKubeConfig() adaptors.KubeConfig {
+	return &KubeConfig{}
+}
+
+type KubeConfig struct{}
+
+func (*KubeConfig) LoadFromFile(filename string) (*api.Config, error) {
+	config, err := clientcmd.LoadFromFile(filename)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not read the kubeconfig from %s", filename)
+	}
+	return config, err
+}
+
+func (*KubeConfig) WriteToFile(config *api.Config, filename string) error {
+	err := clientcmd.WriteToFile(*config, filename)
+	if err != nil {
+		return errors.Wrapf(err, "could not write the kubeconfig to %s", filename)
+	}
+	return err
+}

adaptors/logger.go

@@ -0,0 +1,17 @@
+package adaptors
+
+import (
+	"log"
+
+	"github.com/int128/kubelogin/adaptors/interfaces"
+)
+
+func NewLogger() adaptors.Logger {
+	return &Logger{}
+}
+
+type Logger struct{}
+
+func (*Logger) Logf(format string, v ...interface{}) {
+	log.Printf(format, v...)
+}

adaptors/mock_adaptors/mock_adaptors.go

@@ -0,0 +1,216 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/int128/kubelogin/adaptors/interfaces (interfaces: KubeConfig,HTTP,HTTPClientConfig,OIDC)
+
+// Package mock_adaptors is a generated GoMock package.
+package mock_adaptors
+
+import (
+	context "context"
+	tls "crypto/tls"
+	gomock "github.com/golang/mock/gomock"
+	interfaces "github.com/int128/kubelogin/adaptors/interfaces"
+	api "k8s.io/client-go/tools/clientcmd/api"
+	http "net/http"
+	reflect "reflect"
+)
+
+// MockKubeConfig is a mock of KubeConfig interface
+type MockKubeConfig struct {
+	ctrl     *gomock.Controller
+	recorder *MockKubeConfigMockRecorder
+}
+
+// MockKubeConfigMockRecorder is the mock recorder for MockKubeConfig
+type MockKubeConfigMockRecorder struct {
+	mock *MockKubeConfig
+}
+
+// NewMockKubeConfig creates a new mock instance
+func NewMockKubeConfig(ctrl *gomock.Controller) *MockKubeConfig {
+	mock := &MockKubeConfig{ctrl: ctrl}
+	mock.recorder = &MockKubeConfigMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockKubeConfig) EXPECT() *MockKubeConfigMockRecorder {
+	return m.recorder
+}
+
+// LoadFromFile mocks base method
+func (m *MockKubeConfig) LoadFromFile(arg0 string) (*api.Config, error) {
+	ret := m.ctrl.Call(m, "LoadFromFile", arg0)
+	ret0, _ := ret[0].(*api.Config)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// LoadFromFile indicates an expected call of LoadFromFile
+func (mr *MockKubeConfigMockRecorder) LoadFromFile(arg0 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LoadFromFile", reflect.TypeOf((*MockKubeConfig)(nil).LoadFromFile), arg0)
+}
+
+// WriteToFile mocks base method
+func (m *MockKubeConfig) WriteToFile(arg0 *api.Config, arg1 string) error {
+	ret := m.ctrl.Call(m, "WriteToFile", arg0, arg1)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// WriteToFile indicates an expected call of WriteToFile
+func (mr *MockKubeConfigMockRecorder) WriteToFile(arg0, arg1 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "WriteToFile", reflect.TypeOf((*MockKubeConfig)(nil).WriteToFile), arg0, arg1)
+}
+
+// MockHTTP is a mock of HTTP interface
+type MockHTTP struct {
+	ctrl     *gomock.Controller
+	recorder *MockHTTPMockRecorder
+}
+
+// MockHTTPMockRecorder is the mock recorder for MockHTTP
+type MockHTTPMockRecorder struct {
+	mock *MockHTTP
+}
+
+// NewMockHTTP creates a new mock instance
+func NewMockHTTP(ctrl *gomock.Controller) *MockHTTP {
+	mock := &MockHTTP{ctrl: ctrl}
+	mock.recorder = &MockHTTPMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockHTTP) EXPECT() *MockHTTPMockRecorder {
+	return m.recorder
+}
+
+// NewClient mocks base method
+func (m *MockHTTP) NewClient(arg0 interfaces.HTTPClientConfig) (*http.Client, error) {
+	ret := m.ctrl.Call(m, "NewClient", arg0)
+	ret0, _ := ret[0].(*http.Client)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// NewClient indicates an expected call of NewClient
+func (mr *MockHTTPMockRecorder) NewClient(arg0 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "NewClient", reflect.TypeOf((*MockHTTP)(nil).NewClient), arg0)
+}
+
+// NewClientConfig mocks base method
+func (m *MockHTTP) NewClientConfig() interfaces.HTTPClientConfig {
+	ret := m.ctrl.Call(m, "NewClientConfig")
+	ret0, _ := ret[0].(interfaces.HTTPClientConfig)
+	return ret0
+}
+
+// NewClientConfig indicates an expected call of NewClientConfig
+func (mr *MockHTTPMockRecorder) NewClientConfig() *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "NewClientConfig", reflect.TypeOf((*MockHTTP)(nil).NewClientConfig))
+}
+
+// MockHTTPClientConfig is a mock of HTTPClientConfig interface
+type MockHTTPClientConfig struct {
+	ctrl     *gomock.Controller
+	recorder *MockHTTPClientConfigMockRecorder
+}
+
+// MockHTTPClientConfigMockRecorder is the mock recorder for MockHTTPClientConfig
+type MockHTTPClientConfigMockRecorder struct {
+	mock *MockHTTPClientConfig
+}
+
+// NewMockHTTPClientConfig creates a new mock instance
+func NewMockHTTPClientConfig(ctrl *gomock.Controller) *MockHTTPClientConfig {
+	mock := &MockHTTPClientConfig{ctrl: ctrl}
+	mock.recorder = &MockHTTPClientConfigMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockHTTPClientConfig) EXPECT() *MockHTTPClientConfigMockRecorder {
+	return m.recorder
+}
+
+// AddCertificateFromFile mocks base method
+func (m *MockHTTPClientConfig) AddCertificateFromFile(arg0 string) error {
+	ret := m.ctrl.Call(m, "AddCertificateFromFile", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// AddCertificateFromFile indicates an expected call of AddCertificateFromFile
+func (mr *MockHTTPClientConfigMockRecorder) AddCertificateFromFile(arg0 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "AddCertificateFromFile", reflect.TypeOf((*MockHTTPClientConfig)(nil).AddCertificateFromFile), arg0)
+}
+
+// AddEncodedCertificate mocks base method
+func (m *MockHTTPClientConfig) AddEncodedCertificate(arg0 string) error {
+	ret := m.ctrl.Call(m, "AddEncodedCertificate", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// AddEncodedCertificate indicates an expected call of AddEncodedCertificate
+func (mr *MockHTTPClientConfigMockRecorder) AddEncodedCertificate(arg0 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "AddEncodedCertificate", reflect.TypeOf((*MockHTTPClientConfig)(nil).AddEncodedCertificate), arg0)
+}
+
+// SetSkipTLSVerify mocks base method
+func (m *MockHTTPClientConfig) SetSkipTLSVerify(arg0 bool) {
+	m.ctrl.Call(m, "SetSkipTLSVerify", arg0)
+}
+
+// SetSkipTLSVerify indicates an expected call of SetSkipTLSVerify
+func (mr *MockHTTPClientConfigMockRecorder) SetSkipTLSVerify(arg0 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetSkipTLSVerify", reflect.TypeOf((*MockHTTPClientConfig)(nil).SetSkipTLSVerify), arg0)
+}
+
+// TLSConfig mocks base method
+func (m *MockHTTPClientConfig) TLSConfig() *tls.Config {
+	ret := m.ctrl.Call(m, "TLSConfig")
+	ret0, _ := ret[0].(*tls.Config)
+	return ret0
+}
+
+// TLSConfig indicates an expected call of TLSConfig
+func (mr *MockHTTPClientConfigMockRecorder) TLSConfig() *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "TLSConfig", reflect.TypeOf((*MockHTTPClientConfig)(nil).TLSConfig))
+}
+
+// MockOIDC is a mock of OIDC interface
+type MockOIDC struct {
+	ctrl     *gomock.Controller
+	recorder *MockOIDCMockRecorder
+}
+
+// MockOIDCMockRecorder is the mock recorder for MockOIDC
+type MockOIDCMockRecorder struct {
+	mock *MockOIDC
+}
+
+// NewMockOIDC creates a new mock instance
+func NewMockOIDC(ctrl *gomock.Controller) *MockOIDC {
+	mock := &MockOIDC{ctrl: ctrl}
+	mock.recorder = &MockOIDCMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockOIDC) EXPECT() *MockOIDCMockRecorder {
+	return m.recorder
+}
+
+// Authenticate mocks base method
+func (m *MockOIDC) Authenticate(arg0 context.Context, arg1 interfaces.OIDCAuthenticateIn) (*interfaces.OIDCAuthenticateOut, error) {
+	ret := m.ctrl.Call(m, "Authenticate", arg0, arg1)
+	ret0, _ := ret[0].(*interfaces.OIDCAuthenticateOut)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// Authenticate indicates an expected call of Authenticate
+func (mr *MockOIDCMockRecorder) Authenticate(arg0, arg1 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Authenticate", reflect.TypeOf((*MockOIDC)(nil).Authenticate), arg0, arg1)
+}

adaptors/oidc.go

@@ -0,0 +1,56 @@
+package adaptors
+
+import (
+	"context"
+
+	"github.com/coreos/go-oidc"
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/oauth2cli"
+	"github.com/pkg/errors"
+	"golang.org/x/oauth2"
+)
+
+func NewOIDC() adaptors.OIDC {
+	return &OIDC{}
+}
+
+type OIDC struct{}
+
+func (*OIDC) Authenticate(ctx context.Context, in adaptors.OIDCAuthenticateIn) (*adaptors.OIDCAuthenticateOut, error) {
+	if in.Client != nil {
+		ctx = context.WithValue(ctx, oauth2.HTTPClient, in.Client)
+	}
+	provider, err := oidc.NewProvider(ctx, in.Issuer)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not discovery the OIDC issuer")
+	}
+	flow := oauth2cli.AuthCodeFlow{
+		Config: oauth2.Config{
+			Endpoint:     provider.Endpoint(),
+			ClientID:     in.ClientID,
+			ClientSecret: in.ClientSecret,
+			Scopes:       append(in.ExtraScopes, oidc.ScopeOpenID),
+		},
+		LocalServerPort: in.LocalServerPort,
+		SkipOpenBrowser: in.SkipOpenBrowser,
+		AuthCodeOptions: []oauth2.AuthCodeOption{oauth2.AccessTypeOffline},
+	}
+	token, err := flow.GetToken(ctx)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not get a token")
+	}
+	idToken, ok := token.Extra("id_token").(string)
+	if !ok {
+		return nil, errors.Errorf("id_token is missing in the token response: %s", token)
+	}
+	verifier := provider.Verifier(&oidc.Config{ClientID: in.ClientID})
+	verifiedIDToken, err := verifier.Verify(ctx, idToken)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not verify the id_token")
+	}
+	return &adaptors.OIDCAuthenticateOut{
+		VerifiedIDToken: verifiedIDToken,
+		IDToken:         idToken,
+		RefreshToken:    token.RefreshToken,
+	}, nil
+}

adaptors_test/authserver/handler.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	jwt "github.com/dgrijalva/jwt-go"
+	"github.com/pkg/errors"
 )
 
 type handler struct {
@@ -89,7 +90,7 @@ func (h *handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 		// http://openid.net/specs/openid-connect-core-1_0.html#AuthResponse
 		q := r.URL.Query()
 		if h.Scope != q.Get("scope") {
-			return fmt.Errorf("scope wants %s but %s", h.Scope, q.Get("scope"))
+			return errors.Errorf("scope wants %s but %s", h.Scope, q.Get("scope"))
 		}
 		to := fmt.Sprintf("%s?state=%s&code=%s", q.Get("redirect_uri"), q.Get("state"), h.authCode)
 		http.Redirect(w, r, to, 302)
@@ -100,7 +101,7 @@ func (h *handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
 			return err
 		}
 		if h.authCode != r.Form.Get("code") {
-			return fmt.Errorf("code wants %s but %s", h.authCode, r.Form.Get("code"))
+			return errors.Errorf("code wants %s but %s", h.authCode, r.Form.Get("code"))
 		}
 		w.Header().Add("Content-Type", "application/json")
 		if err := h.token.Execute(w, h); err != nil {

adaptors_test/cmd_test.go

@@ -1,19 +1,21 @@
-package e2e
+package adaptors_test
 
 import (
 	"context"
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/base64"
-	"fmt"
 	"io/ioutil"
 	"net/http"
 	"os"
 	"testing"
 	"time"
 
-	"github.com/int128/kubelogin/cli"
-	"github.com/int128/kubelogin/e2e/authserver"
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/adaptors_test/authserver"
+	"github.com/int128/kubelogin/adaptors_test/kubeconfig"
+	"github.com/int128/kubelogin/di"
+	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -24,25 +26,26 @@ import (
 // 3. Open a request for port 8000.
 // 4. Wait for the CLI.
 // 5. Shutdown the auth server.
-func TestE2E(t *testing.T) {
+//
+func TestCmd_Run(t *testing.T) {
 	data := map[string]struct {
-		kubeconfigValues kubeconfigValues
-		cli              cli.CLI
+		kubeconfigValues kubeconfig.Values
+		args             []string
 		serverConfig     authserver.Config
 		clientTLS        *tls.Config
 	}{
 		"NoTLS": {
-			kubeconfigValues{Issuer: "http://localhost:9000"},
-			cli.CLI{},
+			kubeconfig.Values{Issuer: "http://localhost:9000"},
+			[]string{"kubelogin"},
 			authserver.Config{Issuer: "http://localhost:9000"},
 			&tls.Config{},
 		},
 		"ExtraScope": {
-			kubeconfigValues{
+			kubeconfig.Values{
 				Issuer:      "http://localhost:9000",
 				ExtraScopes: "profile groups",
 			},
-			cli.CLI{},
+			[]string{"kubelogin"},
 			authserver.Config{
 				Issuer: "http://localhost:9000",
 				Scope:  "profile groups openid",
@@ -50,8 +53,8 @@ func TestE2E(t *testing.T) {
 			&tls.Config{},
 		},
 		"SkipTLSVerify": {
-			kubeconfigValues{Issuer: "https://localhost:9000"},
-			cli.CLI{SkipTLSVerify: true},
+			kubeconfig.Values{Issuer: "https://localhost:9000"},
+			[]string{"kubelogin", "--insecure-skip-tls-verify"},
 			authserver.Config{
 				Issuer: "https://localhost:9000",
 				Cert:   authserver.ServerCert,
@@ -60,11 +63,11 @@ func TestE2E(t *testing.T) {
 			&tls.Config{InsecureSkipVerify: true},
 		},
 		"CACert": {
-			kubeconfigValues{
+			kubeconfig.Values{
 				Issuer:                  "https://localhost:9000",
 				IDPCertificateAuthority: authserver.CACert,
 			},
-			cli.CLI{},
+			[]string{"kubelogin"},
 			authserver.Config{
 				Issuer: "https://localhost:9000",
 				Cert:   authserver.ServerCert,
@@ -73,11 +76,11 @@ func TestE2E(t *testing.T) {
 			&tls.Config{RootCAs: readCert(t, authserver.CACert)},
 		},
 		"CACertData": {
-			kubeconfigValues{
-				Issuer: "https://localhost:9000",
+			kubeconfig.Values{
+				Issuer:                      "https://localhost:9000",
 				IDPCertificateAuthorityData: base64.StdEncoding.EncodeToString(read(t, authserver.CACert)),
 			},
-			cli.CLI{},
+			[]string{"kubelogin"},
 			authserver.Config{
 				Issuer: "https://localhost:9000",
 				Cert:   authserver.ServerCert,
@@ -85,6 +88,24 @@ func TestE2E(t *testing.T) {
 			},
 			&tls.Config{RootCAs: readCert(t, authserver.CACert)},
 		},
+		"InvalidCACertShouldBeSkipped": {
+			kubeconfig.Values{
+				Issuer:                  "http://localhost:9000",
+				IDPCertificateAuthority: "cmd_test.go",
+			},
+			[]string{"kubelogin"},
+			authserver.Config{Issuer: "http://localhost:9000"},
+			&tls.Config{},
+		},
+		"InvalidCACertDataShouldBeSkipped": {
+			kubeconfig.Values{
+				Issuer:                      "http://localhost:9000",
+				IDPCertificateAuthorityData: base64.StdEncoding.EncodeToString([]byte("foo")),
+			},
+			[]string{"kubelogin"},
+			authserver.Config{Issuer: "http://localhost:9000"},
+			&tls.Config{},
+		},
 	}
 
 	for name, c := range data {
@@ -93,14 +114,18 @@ func TestE2E(t *testing.T) {
 			defer cancel()
 			server := c.serverConfig.Start(t)
 			defer server.Shutdown(ctx)
-			kubeconfig := createKubeconfig(t, &c.kubeconfigValues)
-			defer os.Remove(kubeconfig)
-			c.cli.KubeConfig = kubeconfig
-			c.cli.SkipOpenBrowser = true
+			kcfg := kubeconfig.Create(t, &c.kubeconfigValues)
+			defer os.Remove(kcfg)
 
+			args := append(c.args, "--kubeconfig", kcfg, "--skip-open-browser")
 			var eg errgroup.Group
 			eg.Go(func() error {
-				return c.cli.Run(ctx)
+				return di.Invoke(func(cmd adaptors.Cmd) {
+					exitCode := cmd.Run(ctx, args, "HEAD")
+					if exitCode != 0 {
+						t.Errorf("exit status wants 0 but %d", exitCode)
+					}
+				})
 			})
 			if err := openBrowserRequest(c.clientTLS); err != nil {
 				cancel()
@@ -109,7 +134,7 @@ func TestE2E(t *testing.T) {
 			if err := eg.Wait(); err != nil {
 				t.Fatalf("CLI returned error: %s", err)
 			}
-			verifyKubeconfig(t, kubeconfig)
+			kubeconfig.Verify(t, kcfg)
 		})
 	}
 }
@@ -119,10 +144,10 @@ func openBrowserRequest(tlsConfig *tls.Config) error {
 	client := http.Client{Transport: &http.Transport{TLSClientConfig: tlsConfig}}
 	res, err := client.Get("http://localhost:8000/")
 	if err != nil {
-		return fmt.Errorf("Could not send a request: %s", err)
+		return errors.Wrapf(err, "could not send a request")
 	}
 	if res.StatusCode != 200 {
-		return fmt.Errorf("StatusCode wants 200 but %d", res.StatusCode)
+		return errors.Errorf("StatusCode wants 200 but %d", res.StatusCode)
 	}
 	return nil
 }

adaptors_test/kubeconfig/kubeconfig.go

@@ -1,4 +1,4 @@
-package e2e
+package kubeconfig
 
 import (
 	"html/template"
@@ -7,21 +7,23 @@ import (
 	"testing"
 )
 
-type kubeconfigValues struct {
+// Values represents values in .kubeconfig template.
+type Values struct {
 	Issuer                      string
 	ExtraScopes                 string
 	IDPCertificateAuthority     string
 	IDPCertificateAuthorityData string
 }
 
-func createKubeconfig(t *testing.T, v *kubeconfigValues) string {
+// Create creates a kubeconfig file and returns path to it.
+func Create(t *testing.T, v *Values) string {
 	t.Helper()
 	f, err := ioutil.TempFile("", "kubeconfig")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer f.Close()
-	tpl, err := template.ParseFiles("testdata/kubeconfig.yaml")
+	tpl, err := template.ParseFiles("kubeconfig/testdata/kubeconfig.yaml")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -31,7 +33,8 @@ func createKubeconfig(t *testing.T, v *kubeconfigValues) string {
 	return f.Name()
 }
 
-func verifyKubeconfig(t *testing.T, kubeconfig string) {
+// Verify returns true if the kubeconfig has valid values.
+func Verify(t *testing.T, kubeconfig string) {
 	b, err := ioutil.ReadFile(kubeconfig)
 	if err != nil {
 		t.Fatal(err)

auth/authcode.go

@@ -1,110 +0,0 @@
-package auth
-
-import (
-	"context"
-	"fmt"
-	"log"
-	"net/http"
-	"time"
-
-	"github.com/pkg/browser"
-	"golang.org/x/oauth2"
-)
-
-type authCodeFlow struct {
-	Config          *oauth2.Config
-	AuthCodeOptions []oauth2.AuthCodeOption
-	ServerPort      int  // HTTP server port
-	SkipOpenBrowser bool // skip opening browser if true
-}
-
-func (f *authCodeFlow) getToken(ctx context.Context) (*oauth2.Token, error) {
-	code, err := f.getAuthCode(ctx)
-	if err != nil {
-		return nil, fmt.Errorf("Could not get an auth code: %s", err)
-	}
-	token, err := f.Config.Exchange(ctx, code)
-	if err != nil {
-		return nil, fmt.Errorf("Could not exchange token: %s", err)
-	}
-	return token, nil
-}
-
-func (f *authCodeFlow) getAuthCode(ctx context.Context) (string, error) {
-	state, err := generateState()
-	if err != nil {
-		return "", fmt.Errorf("Could not generate state parameter: %s", err)
-	}
-	codeCh := make(chan string)
-	defer close(codeCh)
-	errCh := make(chan error)
-	defer close(errCh)
-	server := http.Server{
-		Addr: fmt.Sprintf("localhost:%d", f.ServerPort),
-		Handler: &authCodeHandler{
-			authCodeURL: f.Config.AuthCodeURL(state, f.AuthCodeOptions...),
-			gotCode: func(code string, gotState string) {
-				if gotState == state {
-					codeCh <- code
-				} else {
-					errCh <- fmt.Errorf("State does not match, wants %s but %s", state, gotState)
-				}
-			},
-			gotError: func(err error) {
-				errCh <- err
-			},
-		},
-	}
-	go func() {
-		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-			errCh <- err
-		}
-	}()
-	go func() {
-		log.Printf("Open http://localhost:%d for authorization", f.ServerPort)
-		if !f.SkipOpenBrowser {
-			time.Sleep(500 * time.Millisecond)
-			browser.OpenURL(fmt.Sprintf("http://localhost:%d/", f.ServerPort))
-		}
-	}()
-	select {
-	case err := <-errCh:
-		server.Shutdown(ctx)
-		return "", err
-	case code := <-codeCh:
-		server.Shutdown(ctx)
-		return code, nil
-	case <-ctx.Done():
-		server.Shutdown(ctx)
-		return "", ctx.Err()
-	}
-}
-
-type authCodeHandler struct {
-	authCodeURL string
-	gotCode     func(code string, state string)
-	gotError    func(err error)
-}
-
-func (h *authCodeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	log.Printf("%s %s", r.Method, r.RequestURI)
-	m := r.Method
-	p := r.URL.Path
-	q := r.URL.Query()
-	switch {
-	case m == "GET" && p == "/" && q.Get("error") != "":
-		h.gotError(fmt.Errorf("OAuth Error: %s %s", q.Get("error"), q.Get("error_description")))
-		http.Error(w, "OAuth Error", 500)
-
-	case m == "GET" && p == "/" && q.Get("code") != "":
-		h.gotCode(q.Get("code"), q.Get("state"))
-		w.Header().Add("Content-Type", "text/html")
-		fmt.Fprintf(w, `<html><body>OK<script>window.close()</script></body></html>`)
-
-	case m == "GET" && p == "/":
-		http.Redirect(w, r, h.authCodeURL, 302)
-
-	default:
-		http.Error(w, "Not Found", 404)
-	}
-}

auth/oidc.go

@@ -1,70 +0,0 @@
-package auth
-
-import (
-	"context"
-	"fmt"
-	"log"
-	"net/http"
-
-	oidc "github.com/coreos/go-oidc"
-	"golang.org/x/oauth2"
-)
-
-// TokenSet is a set of tokens and claims.
-type TokenSet struct {
-	IDToken      string
-	RefreshToken string
-}
-
-// Config represents OIDC configuration.
-type Config struct {
-	Issuer          string
-	ClientID        string
-	ClientSecret    string
-	ExtraScopes     []string     // Additional scopes
-	Client          *http.Client // HTTP client for oidc and oauth2
-	ServerPort      int          // HTTP server port
-	SkipOpenBrowser bool         // skip opening browser if true
-}
-
-// GetTokenSet retrives a token from the OIDC provider and returns a TokenSet.
-func (c *Config) GetTokenSet(ctx context.Context) (*TokenSet, error) {
-	if c.Client != nil {
-		ctx = context.WithValue(ctx, oauth2.HTTPClient, c.Client)
-	}
-	provider, err := oidc.NewProvider(ctx, c.Issuer)
-	if err != nil {
-		return nil, fmt.Errorf("Could not discovery the OIDC issuer: %s", err)
-	}
-	oauth2Config := &oauth2.Config{
-		Endpoint:     provider.Endpoint(),
-		ClientID:     c.ClientID,
-		ClientSecret: c.ClientSecret,
-		Scopes:       append(c.ExtraScopes, oidc.ScopeOpenID),
-		RedirectURL:  fmt.Sprintf("http://localhost:%d/", c.ServerPort),
-	}
-	flow := &authCodeFlow{
-		ServerPort:      c.ServerPort,
-		SkipOpenBrowser: c.SkipOpenBrowser,
-		Config:          oauth2Config,
-		AuthCodeOptions: []oauth2.AuthCodeOption{oauth2.AccessTypeOffline},
-	}
-	token, err := flow.getToken(ctx)
-	if err != nil {
-		return nil, fmt.Errorf("Could not get a token: %s", err)
-	}
-	idToken, ok := token.Extra("id_token").(string)
-	if !ok {
-		return nil, fmt.Errorf("id_token is missing in the token response: %s", token)
-	}
-	verifier := provider.Verifier(&oidc.Config{ClientID: c.ClientID})
-	verifiedIDToken, err := verifier.Verify(ctx, idToken)
-	if err != nil {
-		return nil, fmt.Errorf("Could not verify the id_token: %s", err)
-	}
-	log.Printf("Got token for subject=%s", verifiedIDToken.Subject)
-	return &TokenSet{
-		IDToken:      idToken,
-		RefreshToken: token.RefreshToken,
-	}, nil
-}

auth/state.go

@@ -1,15 +0,0 @@
-package auth
-
-import (
-	"crypto/rand"
-	"encoding/binary"
-	"fmt"
-)
-
-func generateState() (string, error) {
-	var n uint64
-	if err := binary.Read(rand.Reader, binary.LittleEndian, &n); err != nil {
-		return "", err
-	}
-	return fmt.Sprintf("%x", n), nil
-}

cli/cli.go

@@ -1,94 +0,0 @@
-package cli
-
-import (
-	"context"
-	"fmt"
-	"log"
-	"net/http"
-
-	"github.com/int128/kubelogin/auth"
-	"github.com/int128/kubelogin/kubeconfig"
-	flags "github.com/jessevdk/go-flags"
-	homedir "github.com/mitchellh/go-homedir"
-)
-
-// Parse parses command line arguments and returns a CLI instance.
-func Parse(osArgs []string, version string) (*CLI, error) {
-	var cli CLI
-	parser := flags.NewParser(&cli, flags.HelpFlag)
-	parser.LongDescription = fmt.Sprintf(`Version %s
-		This updates the kubeconfig for Kubernetes OpenID Connect (OIDC) authentication.`,
-		version)
-	args, err := parser.ParseArgs(osArgs[1:])
-	if err != nil {
-		return nil, err
-	}
-	if len(args) > 0 {
-		return nil, fmt.Errorf("Too many argument")
-	}
-	return &cli, nil
-}
-
-// CLI represents an interface of this command.
-type CLI struct {
-	KubeConfig      string `long:"kubeconfig" default:"~/.kube/config" env:"KUBECONFIG" description:"Path to the kubeconfig file"`
-	SkipTLSVerify   bool   `long:"insecure-skip-tls-verify" env:"KUBELOGIN_INSECURE_SKIP_TLS_VERIFY" description:"If set, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure"`
-	SkipOpenBrowser bool   `long:"skip-open-browser" env:"KUBELOGIN_SKIP_OPEN_BROWSER" description:"If set, it does not open the browser on authentication."`
-}
-
-// ExpandKubeConfig returns an expanded KubeConfig path.
-func (c *CLI) ExpandKubeConfig() (string, error) {
-	d, err := homedir.Expand(c.KubeConfig)
-	if err != nil {
-		return "", fmt.Errorf("Could not expand %s: %s", c.KubeConfig, err)
-	}
-	return d, nil
-}
-
-// Run performs this command.
-func (c *CLI) Run(ctx context.Context) error {
-	log.Printf("Reading %s", c.KubeConfig)
-	path, err := c.ExpandKubeConfig()
-	if err != nil {
-		return err
-	}
-	cfg, err := kubeconfig.Read(path)
-	if err != nil {
-		return fmt.Errorf("Could not read kubeconfig: %s", err)
-	}
-	log.Printf("Using current-context: %s", cfg.CurrentContext)
-	authProvider, err := kubeconfig.FindOIDCAuthProvider(cfg)
-	if err != nil {
-		return fmt.Errorf(`Could not find OIDC configuration in kubeconfig: %s
-			Did you setup kubectl for OIDC authentication?
-				kubectl config set-credentials %s \
-					--auth-provider oidc \
-					--auth-provider-arg idp-issuer-url=https://issuer.example.com \
-					--auth-provider-arg client-id=YOUR_CLIENT_ID \
-					--auth-provider-arg client-secret=YOUR_CLIENT_SECRET`,
-			err, cfg.CurrentContext)
-	}
-	tlsConfig, err := c.tlsConfig(authProvider)
-	if err != nil {
-		return fmt.Errorf("Could not configure TLS: %s", err)
-	}
-	authConfig := &auth.Config{
-		Issuer:          authProvider.IDPIssuerURL(),
-		ClientID:        authProvider.ClientID(),
-		ClientSecret:    authProvider.ClientSecret(),
-		ExtraScopes:     authProvider.ExtraScopes(),
-		Client:          &http.Client{Transport: &http.Transport{TLSClientConfig: tlsConfig}},
-		ServerPort:      8000,
-		SkipOpenBrowser: c.SkipOpenBrowser,
-	}
-	token, err := authConfig.GetTokenSet(ctx)
-	if err != nil {
-		return fmt.Errorf("Could not get token from OIDC provider: %s", err)
-	}
-
-	authProvider.SetIDToken(token.IDToken)
-	authProvider.SetRefreshToken(token.RefreshToken)
-	kubeconfig.Write(cfg, path)
-	log.Printf("Updated %s", c.KubeConfig)
-	return nil
-}

cli/cli_test.go

@@ -1,35 +0,0 @@
-package cli
-
-import (
-	"testing"
-)
-
-func TestParse(t *testing.T) {
-	c, err := Parse([]string{"kubelogin"}, "version")
-	if err != nil {
-		t.Errorf("Parse returned error: %s", err)
-	}
-	if c == nil {
-		t.Errorf("Parse should return CLI but nil")
-	}
-}
-
-func TestParse_TooManyArgs(t *testing.T) {
-	c, err := Parse([]string{"kubelogin", "some"}, "version")
-	if err == nil {
-		t.Errorf("Parse should return error but nil")
-	}
-	if c != nil {
-		t.Errorf("Parse should return nil but %+v", c)
-	}
-}
-
-func TestParse_Help(t *testing.T) {
-	c, err := Parse([]string{"kubelogin", "--help"}, "version")
-	if err == nil {
-		t.Errorf("Parse should return error but nil")
-	}
-	if c != nil {
-		t.Errorf("Parse should return nil but %+v", c)
-	}
-}

cli/tls.go

@@ -1,42 +0,0 @@
-package cli
-
-import (
-	"crypto/tls"
-	"crypto/x509"
-	"encoding/base64"
-	"fmt"
-	"io/ioutil"
-	"log"
-
-	"github.com/int128/kubelogin/kubeconfig"
-)
-
-func (c *CLI) tlsConfig(authProvider *kubeconfig.OIDCAuthProvider) (*tls.Config, error) {
-	p := x509.NewCertPool()
-	if ca := authProvider.IDPCertificateAuthority(); ca != "" {
-		b, err := ioutil.ReadFile(ca)
-		if err != nil {
-			return nil, fmt.Errorf("Could not read %s: %s", ca, err)
-		}
-		if p.AppendCertsFromPEM(b) != true {
-			return nil, fmt.Errorf("Could not append CA certificate from %s", ca)
-		}
-		log.Printf("Using CA certificate: %s", ca)
-	}
-	if ca := authProvider.IDPCertificateAuthorityData(); ca != "" {
-		b, err := base64.StdEncoding.DecodeString(ca)
-		if err != nil {
-			return nil, fmt.Errorf("Could not decode idp-certificate-authority-data: %s", err)
-		}
-		if p.AppendCertsFromPEM(b) != true {
-			return nil, fmt.Errorf("Could not append CA certificate from idp-certificate-authority-data")
-		}
-		log.Printf("Using CA certificate: idp-certificate-authority-data")
-	}
-
-	cfg := &tls.Config{InsecureSkipVerify: c.SkipTLSVerify}
-	if len(p.Subjects()) > 0 {
-		cfg.RootCAs = p
-	}
-	return cfg, nil
-}

di/di.go

@@ -0,0 +1,34 @@
+// Package di provides dependency injection.
+package di
+
+import (
+	"github.com/int128/kubelogin/adaptors"
+	adaptorsInterfaces "github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/usecases"
+	"github.com/pkg/errors"
+	"go.uber.org/dig"
+)
+
+var constructors = []interface{}{
+	usecases.NewLogin,
+
+	adaptors.NewCmd,
+	adaptors.NewKubeConfig,
+	adaptors.NewOIDC,
+	adaptors.NewHTTP,
+	adaptors.NewLogger,
+}
+
+// Invoke runs the function with an adaptors.Cmd instance.
+func Invoke(f func(cmd adaptorsInterfaces.Cmd)) error {
+	c := dig.New()
+	for _, constructor := range constructors {
+		if err := c.Provide(constructor); err != nil {
+			return errors.Wrapf(err, "could not provide the constructor")
+		}
+	}
+	if err := c.Invoke(f); err != nil {
+		return errors.Wrapf(err, "could not invoke")
+	}
+	return nil
+}

di/di_test.go

@@ -0,0 +1,18 @@
+package di_test
+
+import (
+	"testing"
+
+	adaptors "github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/di"
+)
+
+func TestInvoke(t *testing.T) {
+	if err := di.Invoke(func(cmd adaptors.Cmd) {
+		if cmd == nil {
+			t.Errorf("cmd wants non-nil but nil")
+		}
+	}); err != nil {
+		t.Fatalf("Invoke returned error: %+v", err)
+	}
+}

docs/google.md

@@ -0,0 +1,100 @@
+# Getting Started with Google Identity Platform
+
+## Prerequisite
+
+- You have a Google account.
+- You have the Cluster Admin role of the Kubernetes cluster.
+- You can configure the Kubernetes API server.
+- `kubectl` and `kubelogin` are installed to your computer.
+
+## 1. Setup Google API
+
+Open [Google APIs Console](https://console.developers.google.com/apis/credentials) and create an OAuth client with the following setting:
+
+- Application Type: Other
+
+## 2. Setup Kubernetes API server
+
+Configure your Kubernetes API Server accepts [OpenID Connect Tokens](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
+
+### kops
+
+If you are using [kops](https://github.com/kubernetes/kops), run `kops edit cluster` and append the following settings:
+
+```yaml
+spec:
+  kubeAPIServer:
+    oidcIssuerURL: https://accounts.google.com
+    oidcClientID: YOUR_CLIENT_ID.apps.googleusercontent.com
+```
+
+## 3. Setup Kubernetes cluster
+
+Here assign the `cluster-admin` role to you.
+
+```yaml
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: oidc-admin-group
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cluster-admin
+subjects:
+- kind: User
+  name: https://accounts.google.com#1234567890
+```
+
+You can create a custom role and assign it as well.
+
+## 4. Setup kubectl
+
+Configure `kubectl` for the OIDC authentication.
+
+```sh
+kubectl config set-credentials NAME \
+  --auth-provider oidc \
+  --auth-provider-arg idp-issuer-url=https://accounts.google.com \
+  --auth-provider-arg client-id=YOUR_CLIENT_ID.apps.googleusercontent.com \
+  --auth-provider-arg client-secret=YOUR_CLIENT_SECRET
+```
+
+## 5. Run kubelogin
+
+Run `kubelogin`.
+
+```
+% kubelogin
+2018/08/10 10:36:38 Reading .kubeconfig
+2018/08/10 10:36:38 Using current context: hello.k8s.local
+2018/08/10 10:36:41 Open http://localhost:8000 for authorization
+2018/08/10 10:36:45 GET /
+2018/08/10 10:37:07 GET /?state=...&session_state=...&code=ey...
+2018/08/10 10:37:08 Updated .kubeconfig
+```
+
+Now your `~/.kube/config` should be like:
+
+```yaml
+users:
+- name: hello.k8s.local
+  user:
+    auth-provider:
+      config:
+        idp-issuer-url: https://accounts.google.com
+        client-id: YOUR_CLIENT_ID.apps.googleusercontent.com
+        client-secret: YOUR_SECRET
+        id-token: ey...       # kubelogin will update ID token here
+        refresh-token: ey...  # kubelogin will update refresh token here
+      name: oidc
+```
+
+Make sure you can access to the Kubernetes cluster.
+
+```
+% kubectl get nodes
+NAME                                    STATUS    ROLES     AGE       VERSION
+ip-1-2-3-4.us-west-2.compute.internal   Ready     node      21d       v1.9.6
+ip-1-2-3-5.us-west-2.compute.internal   Ready     node      20d       v1.9.6
+```

docs/keycloak.md

@@ -0,0 +1,107 @@
+# Getting Started with Keycloak
+
+## Prerequisite
+
+- You have administrator access to the Keycloak.
+- You have the Cluster Admin role of the Kubernetes cluster.
+- You can configure the Kubernetes API server.
+- `kubectl` and `kubelogin` are installed to your computer.
+
+## 1. Setup Keycloak
+
+Open the Keycloak and create an OIDC client as follows:
+
+- Redirect URL: `http://localhost:8000/`
+- Issuer URL: `https://keycloak.example.com/auth/realms/YOUR_REALM`
+- Client ID: `kubernetes`
+- Groups claim: `groups`
+
+Create a group `kubernetes:admin` and join to it.
+This is used for group based access control.
+
+## 2. Setup Kubernetes API server
+
+Configure your Kubernetes API server accepts [OpenID Connect Tokens](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#openid-connect-tokens).
+
+### kops
+
+If you are using [kops](https://github.com/kubernetes/kops), run `kops edit cluster` and append the following settings:
+
+```yaml
+spec:
+  kubeAPIServer:
+    oidcIssuerURL: https://keycloak.example.com/auth/realms/YOUR_REALM
+    oidcClientID: kubernetes
+    oidcGroupsClaim: groups
+```
+
+## 3. Setup Kubernetes cluster
+
+Here assign the `cluster-admin` role to the `kubernetes:admin` group.
+
+```yaml
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: keycloak-admin-group
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cluster-admin
+subjects:
+- kind: Group
+  name: /kubernetes:admin
+```
+
+You can create a custom role and assign it as well.
+
+## 4. Setup kubectl
+
+Configure `kubectl` for the OIDC authentication.
+
+```sh
+kubectl config set-credentials NAME \
+  --auth-provider oidc \
+  --auth-provider-arg idp-issuer-url=https://keycloak.example.com/auth/realms/YOUR_REALM \
+  --auth-provider-arg client-id=kubernetes \
+  --auth-provider-arg client-secret=YOUR_CLIENT_SECRET
+```
+
+## 5. Run kubelogin
+
+Run `kubelogin`.
+
+```
+% kubelogin
+2018/08/10 10:36:38 Reading .kubeconfig
+2018/08/10 10:36:38 Using current context: hello.k8s.local
+2018/08/10 10:36:41 Open http://localhost:8000 for authorization
+2018/08/10 10:36:45 GET /
+2018/08/10 10:37:07 GET /?state=...&session_state=...&code=ey...
+2018/08/10 10:37:08 Updated .kubeconfig
+```
+
+Now your `~/.kube/config` should be like:
+
+```yaml
+users:
+- name: hello.k8s.local
+  user:
+    auth-provider:
+      config:
+        idp-issuer-url: https://keycloak.example.com/auth/realms/YOUR_REALM
+        client-id: kubernetes
+        client-secret: YOUR_SECRET
+        id-token: ey...       # kubelogin will update ID token here
+        refresh-token: ey...  # kubelogin will update refresh token here
+      name: oidc
+```
+
+Make sure you can access to the Kubernetes cluster.
+
+```
+% kubectl get nodes
+NAME                                    STATUS    ROLES     AGE       VERSION
+ip-1-2-3-4.us-west-2.compute.internal   Ready     node      21d       v1.9.6
+ip-1-2-3-5.us-west-2.compute.internal   Ready     node      20d       v1.9.6
+```

docs/team_ops.md

@@ -0,0 +1,40 @@
+# Team Operation
+
+## kops
+
+Export the kubeconfig.
+
+```sh
+KUBECONFIG=.kubeconfig kops export kubecfg hello.k8s.local
+```
+
+Remove the `admin` access from the kubeconfig.
+It should look as like:
+
+```yaml
+apiVersion: v1
+kind: Config
+clusters:
+  - cluster:
+      certificate-authority-data: LS...
+      server: https://api.hello.k8s.example.com
+      name: hello.k8s.local
+contexts:
+- context:
+    cluster: hello.k8s.local
+    user: hello.k8s.local
+  name: hello.k8s.local
+current-context: hello.k8s.local
+preferences: {}
+users:
+- name: hello.k8s.local
+  user:
+    auth-provider:
+      name: oidc
+      config:
+        client-id: YOUR_CLIEND_ID
+        client-secret: YOUR_CLIENT_SECRET
+        idp-issuer-url: YOUR_ISSUER
+```
+
+You can share the kubeconfig to your team members for easy onboarding.

go.mod

@@ -0,0 +1,35 @@
+module github.com/int128/kubelogin
+
+require (
+	github.com/coreos/go-oidc v2.0.0+incompatible
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible
+	github.com/gogo/protobuf v1.2.1 // indirect
+	github.com/golang/mock v1.2.0
+	github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf // indirect
+	github.com/imdario/mergo v0.3.7 // indirect
+	github.com/int128/oauth2cli v1.1.0
+	github.com/jessevdk/go-flags v1.4.0
+	github.com/json-iterator/go v1.1.6 // indirect
+	github.com/mitchellh/go-homedir v1.1.0
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.1 // indirect
+	github.com/pkg/errors v0.8.1
+	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 // indirect
+	github.com/spf13/pflag v1.0.3 // indirect
+	github.com/stretchr/testify v1.3.0 // indirect
+	go.uber.org/dig v1.7.0
+	golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c // indirect
+	golang.org/x/net v0.0.0-20190328230028-74de082e2cca // indirect
+	golang.org/x/oauth2 v0.0.0-20190319182350-c85d3e98c914
+	golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6
+	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/square/go-jose.v2 v2.3.0 // indirect
+	gopkg.in/yaml.v2 v2.2.2 // indirect
+	k8s.io/api v0.0.0-20190222213804-5cb15d344471 // indirect
+	k8s.io/apimachinery v0.0.0-20190221213512-86fb29eff628 // indirect
+	k8s.io/client-go v10.0.0+incompatible
+	k8s.io/klog v0.2.0 // indirect
+	sigs.k8s.io/yaml v1.1.0 // indirect
+)

go.sum

@@ -0,0 +1,86 @@
+cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
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+github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
+github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
+github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
+github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
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+k8s.io/klog v0.2.0 h1:0ElL0OHzF3N+OhoJTL0uca20SxtYt4X4+bzHeqrB83c=
+k8s.io/klog v0.2.0/go.mod h1:Gq+BEi5rUBO/HRz0bTSXDUcqjScdoY3a9IHpCEIOOfk=
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kubeconfig/auth.go

@@ -1,9 +1,9 @@
 package kubeconfig
 
 import (
-	"fmt"
 	"strings"
 
+	"github.com/pkg/errors"
 	"k8s.io/client-go/tools/clientcmd/api"
 )
 
@@ -13,17 +13,17 @@ import (
 func FindOIDCAuthProvider(config *api.Config) (*OIDCAuthProvider, error) {
 	context := config.Contexts[config.CurrentContext]
 	if context == nil {
-		return nil, fmt.Errorf("context %s does not exist", config.CurrentContext)
+		return nil, errors.Errorf("context %s does not exist", config.CurrentContext)
 	}
 	authInfo := config.AuthInfos[context.AuthInfo]
 	if authInfo == nil {
-		return nil, fmt.Errorf("auth-info %s does not exist", context.AuthInfo)
+		return nil, errors.Errorf("auth-info %s does not exist", context.AuthInfo)
 	}
 	if authInfo.AuthProvider == nil {
-		return nil, fmt.Errorf("auth-provider is not set")
+		return nil, errors.Errorf("auth-provider is not set")
 	}
 	if authInfo.AuthProvider.Name != "oidc" {
-		return nil, fmt.Errorf("auth-provider name is %s but must be oidc", authInfo.AuthProvider.Name)
+		return nil, errors.Errorf("auth-provider name is %s but must be oidc", authInfo.AuthProvider.Name)
 	}
 	return (*OIDCAuthProvider)(authInfo.AuthProvider), nil
 }

kubeconfig/kubeconfig.go

@@ -1,16 +0,0 @@
-package kubeconfig
-
-import (
-	"k8s.io/client-go/tools/clientcmd"
-	"k8s.io/client-go/tools/clientcmd/api"
-)
-
-// Read parses the file and returns the Config.
-func Read(path string) (*api.Config, error) {
-	return clientcmd.LoadFromFile(path)
-}
-
-// Write writes the config to the file.
-func Write(config *api.Config, path string) error {
-	return clientcmd.WriteToFile(*config, path)
-}

kubelogin.rb

@@ -0,0 +1,15 @@
+class Kubelogin < Formula
+  desc "A kubectl plugin for Kubernetes OpenID Connect authentication"
+  homepage "https://github.com/int128/kubelogin"
+  url "https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_darwin_amd64.zip"
+  version "{{ env "VERSION" }}"
+  sha256 "{{ .darwin_amd64_zip_sha256 }}"
+  def install
+    bin.install "kubelogin_darwin_amd64" => "kubelogin"
+    ln_s bin/"kubelogin", bin/"kubectl-oidc_login"
+  end
+  test do
+    system "#{bin}/kubelogin -h"
+    system "#{bin}/kubectl-oidc_login -h"
+  end
+end

main.go

@@ -5,19 +5,16 @@ import (
 	"log"
 	"os"
 
-	"github.com/int128/kubelogin/cli"
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/di"
 )
 
-// Set by goreleaser, see https://goreleaser.com/environment/
-var version = "1.x"
+var version = "HEAD"
 
 func main() {
-	c, err := cli.Parse(os.Args, version)
-	if err != nil {
-		log.Fatal(err)
-	}
-	ctx := context.Background()
-	if err := c.Run(ctx); err != nil {
+	if err := di.Invoke(func(cmd adaptors.Cmd) {
+		os.Exit(cmd.Run(context.Background(), os.Args, version))
+	}); err != nil {
 		log.Fatalf("Error: %s", err)
 	}
 }

oidc-login.yaml

@@ -0,0 +1,57 @@
+apiVersion: krew.googlecontainertools.github.com/v1alpha2
+kind: Plugin
+metadata:
+  name: oidc-login
+spec:
+  shortDescription: Login for OpenID Connect authentication
+  description: |
+    This plugin gets a token from the OIDC provider and writes it to the kubeconfig.
+
+    Just run:
+      % kubectl oidc-login
+
+    It opens the browser and you can log in to the provider.
+    After authentication, it gets an ID token and refresh token and writes them to the kubeconfig.
+
+  caveats: |
+    You need to setup the following components:
+      * OIDC provider
+      * Kubernetes API server
+      * Role for your group or user
+      * kubectl authentication
+
+    See https://github.com/int128/kubelogin for more.
+
+  homepage: https://github.com/int128/kubelogin
+  version: {{ env "VERSION" }}
+  platforms:
+    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_linux_amd64.zip
+      sha256: "{{ .linux_amd64_zip_sha256 }}"
+      bin: kubelogin
+      files:
+        - from: "kubelogin"
+          to: "."
+      selector:
+        matchLabels:
+          os: linux
+          arch: amd64
+    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_darwin_amd64.zip
+      sha256: "{{ .darwin_amd64_zip_sha256 }}"
+      bin: kubelogin
+      files:
+        - from: "kubelogin"
+          to: "."
+      selector:
+        matchLabels:
+          os: darwin
+          arch: amd64
+    - uri: https://github.com/int128/kubelogin/releases/download/{{ env "VERSION" }}/kubelogin_windows_amd64.zip
+      sha256: "{{ .windows_amd64_zip_sha256 }}"
+      bin: kubelogin.exe
+      files:
+        - from: "kubelogin.exe"
+          to: "."
+      selector:
+        matchLabels:
+          os: windows
+          arch: amd64

usecases/interfaces/usecases.go

@@ -0,0 +1,16 @@
+package usecases
+
+import "context"
+
+//go:generate mockgen -package mock_usecases -destination ../mock_usecases/mock_usecases.go github.com/int128/kubelogin/usecases/interfaces Login
+
+type Login interface {
+	Do(ctx context.Context, in LoginIn) error
+}
+
+type LoginIn struct {
+	KubeConfig      string
+	SkipTLSVerify   bool
+	SkipOpenBrowser bool
+	ListenPort      int
+}

usecases/login.go

@@ -0,0 +1,87 @@
+package usecases
+
+import (
+	"context"
+
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/kubeconfig"
+	"github.com/int128/kubelogin/usecases/interfaces"
+	"github.com/pkg/errors"
+	"go.uber.org/dig"
+)
+
+const oidcConfigErrorMessage = `No OIDC configuration found. Did you setup kubectl for OIDC authentication?
+  kubectl config set-credentials %[1]s \
+    --auth-provider oidc \
+    --auth-provider-arg idp-issuer-url=https://issuer.example.com \
+    --auth-provider-arg client-id=YOUR_CLIENT_ID \
+    --auth-provider-arg client-secret=YOUR_CLIENT_SECRET`
+
+func NewLogin(i Login) usecases.Login {
+	return &i
+}
+
+type Login struct {
+	dig.In
+	KubeConfig adaptors.KubeConfig
+	HTTP       adaptors.HTTP
+	OIDC       adaptors.OIDC
+	Logger     adaptors.Logger
+}
+
+func (u *Login) Do(ctx context.Context, in usecases.LoginIn) error {
+	cfg, err := u.KubeConfig.LoadFromFile(in.KubeConfig)
+	if err != nil {
+		return errors.Wrapf(err, "could not read the kubeconfig")
+	}
+
+	u.Logger.Logf("Using current-context: %s", cfg.CurrentContext)
+	authProvider, err := kubeconfig.FindOIDCAuthProvider(cfg)
+	if err != nil {
+		u.Logger.Logf(oidcConfigErrorMessage, cfg.CurrentContext)
+		return errors.Wrapf(err, "could not find an oidc auth-provider in the kubeconfig")
+	}
+
+	clientConfig := u.HTTP.NewClientConfig()
+	clientConfig.SetSkipTLSVerify(in.SkipTLSVerify)
+	if authProvider.IDPCertificateAuthority() != "" {
+		filename := authProvider.IDPCertificateAuthority()
+		u.Logger.Logf("Using the certificate %s", filename)
+		if err := clientConfig.AddCertificateFromFile(filename); err != nil {
+			u.Logger.Logf("Skip the certificate %s: %s", filename, err)
+		}
+	}
+	if authProvider.IDPCertificateAuthorityData() != "" {
+		encoded := authProvider.IDPCertificateAuthorityData()
+		u.Logger.Logf("Using certificate of idp-certificate-authority-data")
+		if err := clientConfig.AddEncodedCertificate(encoded); err != nil {
+			u.Logger.Logf("Skip the certificate of idp-certificate-authority-data: %s", err)
+		}
+	}
+	hc, err := u.HTTP.NewClient(clientConfig)
+	if err != nil {
+		return errors.Wrapf(err, "could not create a HTTP client")
+	}
+
+	out, err := u.OIDC.Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+		Issuer:          authProvider.IDPIssuerURL(),
+		ClientID:        authProvider.ClientID(),
+		ClientSecret:    authProvider.ClientSecret(),
+		ExtraScopes:     authProvider.ExtraScopes(),
+		Client:          hc,
+		LocalServerPort: in.ListenPort,
+		SkipOpenBrowser: in.SkipOpenBrowser,
+	})
+	if err != nil {
+		return errors.Wrapf(err, "could not get token from OIDC provider")
+	}
+
+	u.Logger.Logf("Got a token for subject=%s", out.VerifiedIDToken.Subject)
+	authProvider.SetIDToken(out.IDToken)
+	authProvider.SetRefreshToken(out.RefreshToken)
+	if err := u.KubeConfig.WriteToFile(cfg, in.KubeConfig); err != nil {
+		return errors.Wrapf(err, "could not update the kubeconfig")
+	}
+	u.Logger.Logf("Updated %s", in.KubeConfig)
+	return nil
+}

usecases/login_test.go

@@ -0,0 +1,426 @@
+package usecases
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/coreos/go-oidc"
+	"github.com/golang/mock/gomock"
+	"github.com/int128/kubelogin/adaptors/interfaces"
+	"github.com/int128/kubelogin/adaptors/mock_adaptors"
+	"github.com/int128/kubelogin/usecases/interfaces"
+	"github.com/pkg/errors"
+	"k8s.io/client-go/tools/clientcmd/api"
+)
+
+func TestLogin_Do(t *testing.T) {
+	httpClient := &http.Client{}
+
+	newMockKubeConfig := func(ctrl *gomock.Controller, in *api.Config, out *api.Config) adaptors.KubeConfig {
+		kubeConfig := mock_adaptors.NewMockKubeConfig(ctrl)
+		kubeConfig.EXPECT().
+			LoadFromFile("/path/to/kubeconfig").
+			Return(in, nil)
+		kubeConfig.EXPECT().
+			WriteToFile(out, "/path/to/kubeconfig")
+		return kubeConfig
+	}
+
+	newMockHTTP := func(ctrl *gomock.Controller, config adaptors.HTTPClientConfig) adaptors.HTTP {
+		mockHTTP := mock_adaptors.NewMockHTTP(ctrl)
+		mockHTTP.EXPECT().
+			NewClientConfig().
+			Return(config)
+		mockHTTP.EXPECT().
+			NewClient(config).
+			Return(httpClient, nil)
+		return mockHTTP
+	}
+
+	newInConfig := func() *api.Config {
+		return &api.Config{
+			APIVersion:     "v1",
+			CurrentContext: "default",
+			Contexts: map[string]*api.Context{
+				"default": {
+					AuthInfo: "google",
+					Cluster:  "example.k8s.local",
+				},
+			},
+			AuthInfos: map[string]*api.AuthInfo{
+				"google": {
+					AuthProvider: &api.AuthProviderConfig{
+						Name: "oidc",
+						Config: map[string]string{
+							"client-id":      "YOUR_CLIENT_ID",
+							"client-secret":  "YOUR_CLIENT_SECRET",
+							"idp-issuer-url": "https://accounts.google.com",
+						},
+					},
+				},
+			},
+		}
+	}
+
+	newOutConfig := func(in *api.Config) *api.Config {
+		config := in.DeepCopy()
+		config.AuthInfos["google"].AuthProvider.Config["id-token"] = "YOUR_ID_TOKEN"
+		config.AuthInfos["google"].AuthProvider.Config["refresh-token"] = "YOUR_REFRESH_TOKEN"
+		return config
+	}
+
+	t.Run("Defaults", func(t *testing.T) {
+		inConfig := newInConfig()
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("SkipTLSVerify", func(t *testing.T) {
+		inConfig := newInConfig()
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(true)
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig:    "/path/to/kubeconfig",
+			ListenPort:    10000,
+			SkipTLSVerify: true,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("SkipOpenBrowser", func(t *testing.T) {
+		inConfig := newInConfig()
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+				SkipOpenBrowser: true,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig:      "/path/to/kubeconfig",
+			ListenPort:      10000,
+			SkipOpenBrowser: true,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("KubeConfig/extra-scopes", func(t *testing.T) {
+		inConfig := newInConfig()
+		inConfig.AuthInfos["google"].AuthProvider.Config["extra-scopes"] = "email,profile"
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{"email", "profile"},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("KubeConfig/idp-certificate-authority", func(t *testing.T) {
+		inConfig := newInConfig()
+		inConfig.AuthInfos["google"].AuthProvider.Config["idp-certificate-authority"] = "/path/to/cert"
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+		httpClientConfig.EXPECT().
+			AddCertificateFromFile("/path/to/cert")
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("KubeConfig/idp-certificate-authority/error", func(t *testing.T) {
+		inConfig := newInConfig()
+		inConfig.AuthInfos["google"].AuthProvider.Config["idp-certificate-authority"] = "/path/to/cert"
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+		httpClientConfig.EXPECT().
+			AddCertificateFromFile("/path/to/cert").
+			Return(errors.New("not found"))
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("KubeConfig/idp-certificate-authority-data", func(t *testing.T) {
+		inConfig := newInConfig()
+		inConfig.AuthInfos["google"].AuthProvider.Config["idp-certificate-authority-data"] = "base64encoded"
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+		httpClientConfig.EXPECT().
+			AddEncodedCertificate("base64encoded")
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+
+	t.Run("KubeConfig/idp-certificate-authority-data/error", func(t *testing.T) {
+		inConfig := newInConfig()
+		inConfig.AuthInfos["google"].AuthProvider.Config["idp-certificate-authority-data"] = "base64encoded"
+		outConfig := newOutConfig(inConfig)
+
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		ctx := context.TODO()
+
+		httpClientConfig := mock_adaptors.NewMockHTTPClientConfig(ctrl)
+		httpClientConfig.EXPECT().
+			SetSkipTLSVerify(false)
+		httpClientConfig.EXPECT().
+			AddEncodedCertificate("base64encoded").
+			Return(errors.New("invalid"))
+
+		mockOIDC := mock_adaptors.NewMockOIDC(ctrl)
+		mockOIDC.EXPECT().
+			Authenticate(ctx, adaptors.OIDCAuthenticateIn{
+				Issuer:          "https://accounts.google.com",
+				ClientID:        "YOUR_CLIENT_ID",
+				ClientSecret:    "YOUR_CLIENT_SECRET",
+				ExtraScopes:     []string{},
+				LocalServerPort: 10000,
+				Client:          httpClient,
+			}).
+			Return(&adaptors.OIDCAuthenticateOut{
+				VerifiedIDToken: &oidc.IDToken{Subject: "SUBJECT"},
+				IDToken:         "YOUR_ID_TOKEN",
+				RefreshToken:    "YOUR_REFRESH_TOKEN",
+			}, nil)
+
+		u := Login{
+			KubeConfig: newMockKubeConfig(ctrl, inConfig, outConfig),
+			HTTP:       newMockHTTP(ctrl, httpClientConfig),
+			OIDC:       mockOIDC,
+			Logger:     t,
+		}
+		if err := u.Do(ctx, usecases.LoginIn{
+			KubeConfig: "/path/to/kubeconfig",
+			ListenPort: 10000,
+		}); err != nil {
+			t.Errorf("Do returned error: %+v", err)
+		}
+	})
+}

usecases/mock_usecases/mock_usecases.go

@@ -0,0 +1,47 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/int128/kubelogin/usecases/interfaces (interfaces: Login)
+
+// Package mock_usecases is a generated GoMock package.
+package mock_usecases
+
+import (
+	context "context"
+	gomock "github.com/golang/mock/gomock"
+	interfaces "github.com/int128/kubelogin/usecases/interfaces"
+	reflect "reflect"
+)
+
+// MockLogin is a mock of Login interface
+type MockLogin struct {
+	ctrl     *gomock.Controller
+	recorder *MockLoginMockRecorder
+}
+
+// MockLoginMockRecorder is the mock recorder for MockLogin
+type MockLoginMockRecorder struct {
+	mock *MockLogin
+}
+
+// NewMockLogin creates a new mock instance
+func NewMockLogin(ctrl *gomock.Controller) *MockLogin {
+	mock := &MockLogin{ctrl: ctrl}
+	mock.recorder = &MockLoginMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockLogin) EXPECT() *MockLoginMockRecorder {
+	return m.recorder
+}
+
+// Do mocks base method
+func (m *MockLogin) Do(arg0 context.Context, arg1 interfaces.LoginIn) error {
+	ret := m.ctrl.Call(m, "Do", arg0, arg1)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Do indicates an expected call of Do
+func (mr *MockLoginMockRecorder) Do(arg0, arg1 interface{}) *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Do", reflect.TypeOf((*MockLogin)(nil).Do), arg0, arg1)
+}