Add support to multi architecture docker image using a github action

.github/workflows/docker-builds.yml

@@ -0,0 +1,42 @@
+name: Build and publish cfssl docker image
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Get tag
+        id: cfssl
+        run: echo  "::set-output name=tag::$(git describe --tags HEAD)"
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Log in to the Docker hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v3
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64,linux/s390x
+          push: true
+          tags: cfssl:${{ steps.cfssl.outputs.tag }}

Dockerfile

@@ -1,11 +1,13 @@
-FROM golang:1.16.15@sha256:35fa3cfd4ec01a520f6986535d8f70a5eeef2d40fb8019ff626da24989bdd4f1
+FROM --platform=${BUILDPLATFORM} golang:1.19.3@sha256:d388153691a825844ebb3586dd04d1c60a2215522cc445701424205dffc8a83e
+
+ARG TARGETOS TARGETARCH
 
 WORKDIR /workdir
 COPY . /workdir
 
 RUN git clone https://github.com/cloudflare/cfssl_trust.git /etc/cfssl && \
     make clean && \
-    make all && cp bin/* /usr/bin/
+    GOOS=${TARGETOS} GOARCH=${TARGETARCH} make all && cp bin/* /usr/bin/
 
 EXPOSE 8888
 

Makefile

@@ -9,7 +9,7 @@ all: bin/cfssl bin/cfssl-bundle bin/cfssl-certinfo bin/cfssl-newkey bin/cfssl-sc
 
 bin/%: $(shell find . -type f -name '*.go')
 	@mkdir -p $(dir $@)
-	go build -ldflags $(LDFLAGS) -o $@ ./cmd/$(@F)
+	GOOS=$(TARGETOS) GOARCH=$(TARGETARCH) go build -ldflags $(LDFLAGS) -o $@ ./cmd/$(@F)
 
 .PHONY: install
 install: install-cfssl install-cfssl-bundle install-cfssl-certinfo install-cfssl-newkey install-cfssl-scan install-cfssljson install-mkbundle install-multirootca
@@ -25,7 +25,7 @@ serve:
 
 bin/goose: $(shell find vendor -type f -name '*.go')
 	@mkdir -p $(dir $@)
-	go build -o $@ ./vendor/bitbucket.org/liamstask/goose/cmd/goose
+	GOOS=$(TARGETOS) GOARCH=$(TARGETARCH) go build -o $@ ./vendor/bitbucket.org/liamstask/goose/cmd/goose
 
 .PHONY: clean
 clean: