Use tonistiigi/xx for cross-platform builds

.github/workflows/build.yaml

@@ -12,13 +12,28 @@ jobs:
     steps:
     - name: checkout
       uses: actions/checkout@v2
+    - name: Setup QEMU
+      uses: docker/setup-qemu-action@v1
+      with:
+        platforms: all
+    - name: Setup Docker Buildx
+      id: buildx
+      uses: docker/setup-buildx-action@v1
     - name: Restore go cache
       uses: actions/cache@v1
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ hashFiles('go.sum') }}
         restore-keys: |
           ${{ runner.os }}-go-
+    - name: Cache Docker layers
+      uses: actions/cache@v2
+      id: cache
+      with:
+        path: /tmp/.buildx-cache
+        key: ${{ runner.os }}-buildx-ghcache-${{ github.sha }}
+        restore-keys: |
+          ${{ runner.os }}-buildx-ghcache-
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
@@ -28,4 +43,15 @@ jobs:
     - name: Run tests
       run: make test
     - name: Build container image
-      run: make docker-build IMG=ghcr.io/fluxcd/${{ github.event.repository.name }}:latest
+      run: |
+        make docker-build IMG=ghcr.io/fluxcd/${{ github.event.repository.name }}:latest \
+          BUILD_PLATFORMS=linux/amd64 \
+          BUILD_ARGS="--cache-from=type=local,src=/tmp/.buildx-cache \
+            --cache-to=type=local,dest=/tmp/.buildx-cache-new,mode=max"
+    - # Temp fix
+      # https://github.com/docker/build-push-action/issues/252
+      # https://github.com/moby/buildkit/issues/1896
+      name: Move cache
+      run: |
+        rm -rf /tmp/.buildx-cache
+        mv /tmp/.buildx-cache-new /tmp/.buildx-cache

Dockerfile

@@ -1,6 +1,16 @@
+ARG XX_VERSION=1.0.0-rc.2
+
+FROM --platform=$BUILDPLATFORM tonistiigi/xx:${XX_VERSION} AS xx
+
 # Build the manager binary
-FROM golang:1.16-alpine as builder
+FROM --platform=$BUILDPLATFORM golang:1.16-alpine AS builder
+
+# Copy the build utilities.
+COPY --from=xx / /
+
+ARG TARGETPLATFORM
 
+# Configure workspace.
 WORKDIR /workspace
 
 # copy modules manifests
@@ -20,7 +30,8 @@ COPY controllers/ controllers/
 COPY internal/ internal/
 
 # build without giving the arch, so that it gets it from the machine
-RUN CGO_ENABLED=0 go build -a -o image-reflector-controller main.go
+ENV CGO_ENABLED=0
+RUN xx-go build -a -o image-reflector-controller main.go
 
 FROM alpine:3.13
 

Makefile

@@ -6,6 +6,11 @@ CRD_OPTIONS ?= crd:crdVersions=v1
 ENVTEST_BIN_VERSION?=1.22.0
 KUBEBUILDER_ASSETS?=$(shell $(SETUP_ENVTEST) use -i $(ENVTEST_BIN_VERSION) -p path)
 
+# Allows for defining additional Docker buildx arguments, e.g. '--push'.
+BUILD_ARGS ?=
+# Architectures to build images for.
+BUILD_PLATFORMS ?= linux/amd64
+
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))
 GOBIN=$(shell go env GOPATH)/bin
@@ -76,8 +81,12 @@ generate: controller-gen
 	cd api; $(CONTROLLER_GEN) object:headerFile="../hack/boilerplate.go.txt" paths="./..."
 
 # Build the docker image
-docker-build: test
-	docker build . -t ${IMG}
+docker-build:
+	docker buildx build \
+	--platform=$(BUILD_PLATFORMS) \
+	-t ${IMG} \
+	--load \
+	${BUILD_ARGS} .
 
 # Push the docker image
 docker-push: