ci: build multi arch images with buildx

.github/workflows/build_image.yml

@@ -0,0 +1,31 @@
+name: Build Image
+
+on:
+  push:
+    branches:
+      - 'master'
+    tags:
+      - "*"
+
+jobs:
+  bake:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+        with:
+          buildkitd-flags: --debug
+          config-inline: |
+            [registry."docker.io"]
+              mirrors = ["mirror.gcr.io"]
+      - name: Build image
+        run: |
+          make docker
+      - name: Pubish to Dockerhub
+        if: ${{ startsWith(github.ref, 'refs/tags/') }}
+        run: |
+          make release

Dockerfile

@@ -1,11 +1,16 @@
-FROM golang:1.16.0 AS BUILDER
+FROM --platform=$TARGETPLATFORM golang:1.16.0 AS BUILDER
+
+ARG TARGETPLATFORM
+ARG TARGETARCH
+ARG BUILDPLATFORM
+
 WORKDIR /go/src/github.com/jtblin/kube2iam
 ENV ARCH=linux
 ENV CGO_ENABLED=0
 COPY . ./
 RUN make setup && make build
 
-FROM alpine:3.14.3
+FROM --platform=$TARGETPLATFORM alpine:3.14.3
 RUN apk --no-cache add \
     ca-certificates \
     iptables

Makefile

@@ -10,8 +10,8 @@ GIT_HASH := $$(git rev-parse --short HEAD)
 GOBUILD_VERSION_ARGS := -ldflags "-s -X $(VERSION_VAR)=$(REPO_VERSION) -X $(GIT_VAR)=$(GIT_HASH) -X $(BUILD_DATE_VAR)=$(BUILD_DATE)"
 # useful for other docker repos
 DOCKER_REPO ?= jtblin
-CPU_ARCH ?= amd64
-IMAGE_NAME := $(DOCKER_REPO)/$(BINARY_NAME)-$(CPU_ARCH)
+CPU_ARCH ?= linux/arm64/v8,linux/amd64
+IMAGE_NAME := $(DOCKER_REPO)/$(BINARY_NAME)
 MANIFEST_NAME := $(DOCKER_REPO)/$(BINARY_NAME)
 ARCH ?= darwin
 GOLANGCI_LINT_VERSION ?= v1.23.8
@@ -74,16 +74,14 @@ check-all:
 travis-checks: build test-race check bench-race
 
 docker:
-	docker build -t $(IMAGE_NAME):$(GIT_HASH) . $(DOCKER_BUILD_FLAGS)
+	docker buildx build --progress=plain --platform $(CPU_ARCH) -t $(IMAGE_NAME):$(GIT_HASH) . $(DOCKER_BUILD_FLAGS)
 
 docker-dev: docker
 	docker tag $(IMAGE_NAME):$(GIT_HASH) $(IMAGE_NAME):dev
 	docker push $(IMAGE_NAME):dev
 
 release: check test docker
-	docker push $(IMAGE_NAME):$(GIT_HASH)
-	docker tag $(IMAGE_NAME):$(GIT_HASH) $(IMAGE_NAME):$(REPO_VERSION)
-	docker push $(IMAGE_NAME):$(REPO_VERSION)
+	docker buildx build --push --progress=plain --platform $(CPU_ARCH) -t $(IMAGE_NAME):$(GIT_HASH) . $(DOCKER_BUILD_FLAGS)
 ifeq (, $(findstring -rc, $(REPO_VERSION)))
 	docker tag $(IMAGE_NAME):$(GIT_HASH) $(IMAGE_NAME):latest
 	docker push $(IMAGE_NAME):latest