From d7b19a4930772df4af623b5f234945dc43153d32 Mon Sep 17 00:00:00 2001
From: Davide Imola <davide.imola@icloud.com>
Date: Fri, 5 Mar 2021 21:02:41 +0100
Subject: [PATCH] build: using Docker build args for build metadata (#217)

---
 Dockerfile | 20 +++++++++-----------
 Makefile   | 16 +++++++++++++++-
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 1e00430f..380b2b5f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,13 @@
 # Build the manager binary
 FROM golang:1.13 as builder
 
+ARG GIT_HEAD_COMMIT
+ARG GIT_TAG_COMMIT
+ARG GIT_LAST_TAG
+ARG GIT_MODIFIED
+ARG GIT_REPO
+ARG BUILD_DATE
+
 WORKDIR /workspace
 # Copy the Go Modules manifests
 COPY go.mod go.mod
@@ -15,20 +22,11 @@ COPY version.go version.go
 COPY api/ api/
 COPY controllers/ controllers/
 COPY pkg/ pkg/
-COPY .git .git
 
 # Build
-RUN git config --get remote.origin.url > /tmp/GIT_REPO && \
-    git rev-parse --short HEAD > /tmp/GIT_HEAD_COMMIT && \
-    git describe --abbrev=0 --tags > /tmp/GIT_LAST_TAG && \
-    git rev-parse --short $(cat /tmp/GIT_LAST_TAG) > /tmp/GIT_TAG_COMMIT && \
-    git diff $(cat /tmp/GIT_HEAD_COMMIT) $(cat /tmp/GIT_TAG_COMMIT) --quiet > /tmp/GIT_MODIFIED1 || echo '.dev' > /tmp/GIT_MODIFIED1 && \
-    git diff --quiet > /tmp/GIT_MODIFIED2 || echo '.dirty' > /tmp/GIT_MODIFIED2 && \
-    cat /tmp/GIT_MODIFIED1 /tmp/GIT_MODIFIED2 | tr -d '\n' > /tmp/GIT_MODIFIED && \
-    date '+%Y-%m-%dT%H:%M:%S' > /tmp/BUILD_DATE &&\
-    CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build \
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build \
         -gcflags "-N -l" \
-        -ldflags "-X main.GitRepo=$(cat /tmp/GIT_REPO) -X main.GitTag=$(cat /tmp/GIT_LAST_TAG) -X main.GitCommit=$(cat /tmp/GIT_HEAD_COMMIT) -X main.GitDirty=$(cat /tmp/GIT_MODIFIED) -X main.BuildTime=$(cat /tmp/BUILD_DATE)" \
+        -ldflags "-X main.GitRepo=$GIT_REPO -X main.GitTag=$GIT_LAST_TAG -X main.GitCommit=$GIT_HEAD_COMMIT -X main.GitDirty=$GIT_MODIFIED -X main.BuildTime=$BUILD_DATE" \
         -o manager
 
 # Use distroless as minimal base image to package the manager binary
diff --git a/Makefile b/Makefile
index 1c9c55ee..b279f343 100644
--- a/Makefile
+++ b/Makefile
@@ -24,6 +24,15 @@ else
 GOBIN=$(shell go env GOBIN)
 endif
 
+# Get information about git current status
+GIT_HEAD_COMMIT ?= $$(git rev-parse --short HEAD)
+GIT_TAG_COMMIT  ?= $$(git rev-parse --short $(VERSION))
+GIT_MODIFIED_1  ?= $$(git diff $(GIT_HEAD_COMMIT) $(GIT_TAG_COMMIT) --quiet && echo "" || echo ".dev")
+GIT_MODIFIED_2  ?= $$(git diff --quiet && echo "" || echo ".dirty")
+GIT_MODIFIED    ?= $$(echo "$(GIT_MODIFIED_1)$(GIT_MODIFIED_2)")
+GIT_REPO        ?= $$(git config --get remote.origin.url)
+BUILD_DATE      ?= $$(date '+%Y-%m-%dT%H:%M:%S')
+
 all: manager
 
 # Run tests
@@ -75,7 +84,12 @@ generate: controller-gen
 
 # Build the docker image
 docker-build: test
-	docker build . -t ${IMG}
+	docker build . -t ${IMG} --build-arg GIT_HEAD_COMMIT=$(GIT_HEAD_COMMIT) \
+ 							 --build-arg GIT_TAG_COMMIT=$(GIT_TAG_COMMIT) \
+ 							 --build-arg GIT_MODIFIED=$(GIT_MODIFIED) \
+ 							 --build-arg GIT_REPO=$(GIT_REPO) \
+ 							 --build-arg GIT_LAST_TAG=$(VERSION) \
+ 							 --build-arg BUILD_DATE=$(BUILD_DATE)
 
 # Push the docker image
 docker-push: