feat: support for multiarch images

This commit alters the Dockerfile for both regular and OpenShift in such
a way multiarch images are getting built when using buildkit. Also, the
GH workflow actually building the images is prepared for that.

Fixes k8snetworkplumbingwg#226

Signed-off-by: Jorik Jonker <jorik.jonker@eu.equinix.com>

.github/workflows/image-build.yml

@@ -1,8 +1,8 @@
 name: Image build
 on: [pull_request]
 jobs:
-  build-amd64:
-    name: Image build/amd64
+  build-multiarch:
+    name: Image build
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
@@ -16,30 +16,13 @@ jobs:
         with:
           context: .
           push: false
-          tags: ghcr.io/${{ github.repository }}:latest-amd64
+          tags: ghcr.io/${{ github.repository }}:latest
           file: Dockerfile
+          platforms: [linux/arm64, linux/amd64]
 
   build-openshift:
     name: Image build/openshift
     runs-on: ubuntu-latest
-    steps:
-      - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
-
-      - name: Build container image
-        uses: docker/build-push-action@v2
-        with:
-          context: .
-          push: false
-          tags: k8snetworkplumbingwg/whereabouts-ocp
-          file: Dockerfile.openshift
-
-  build-arm64:
-    name: Image build/arm64
-    runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
         uses: actions/checkout@v2
@@ -55,6 +38,6 @@ jobs:
         with:
           context: .
           push: false
-          tags: ghcr.io/${{ github.repository }}:latest-arm64
-          file: Dockerfile.arm64
-          platforms: linux/arm64
+          tags: k8snetworkplumbingwg/whereabouts-ocp
+          file: Dockerfile.openshift
+          platforms: [linux/arm64, linux/amd64]

.github/workflows/image-push-master.yml

@@ -6,8 +6,8 @@ on:
 env:
   image-push-owner: 'k8snetworkplumbingwg'
 jobs:
-  push-amd64:
-    name: Image push/amd64
+  push:
+    name: Image push
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
@@ -30,8 +30,9 @@ jobs:
         with:
           context: .
           push: true
-          tags: ghcr.io/${{ github.repository }}:latest-amd64
+          tags: ghcr.io/${{ github.repository }}:latest
           file: Dockerfile
+          platforms: linux/arm64,linux/amd64
 
   push-origin:
     name: Image push/origin
@@ -59,24 +60,4 @@ jobs:
           push: true
           tags: ghcr.io/${{ github.repository }}:latest-ocp
           file: Dockerfile.openshift
-
-  push-arm64:
-    name: Image build/arm64
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
-
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
-
-      - name: Build container image
-        uses: docker/build-push-action@v2
-        with:
-          context: .
-          push: true
-          tags: ghcr.io/${{ github.repository }}:latest-arm64
-          file: Dockerfile.arm64
+          platforms: linux/arm64,linux/amd64

.github/workflows/image-push-release.yml

@@ -7,7 +7,7 @@ env:
   image-push-owner: 'k8snetworkplumbingwg'
 jobs:
   push-amd64:
-    name: Image push/amd64
+    name: Image push
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
@@ -38,44 +38,6 @@ jobs:
           context: .
           push: true
           tags: |
-            ${{ steps.docker_meta.outputs.tags }}-amd64
+            ${{ steps.docker_meta.outputs.tags }}
           file: Dockerfile
-
-  push-arm64:
-    name: Image push/arm64
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
-
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
-
-      - name: Login to Container Registry
-        if: github.repository_owner == 'k8snetworkplumbingwg'
-        uses: docker/login-action@v1
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Docker meta
-        id: docker_meta
-        uses: crazy-max/ghaction-docker-meta@v1
-        with:
-          images: ghcr.io/${{ github.repository }}
-          tag-latest: false
-
-      - name: Push container image
-        if: github.repository_owner == 'k8snetworkplumbingwg'
-        uses: docker/build-push-action@v2
-        with:
-          context: .
-          push: true
-          tags: |
-            ${{ steps.docker_meta.outputs.tags }}-arm64
-          file: Dockerfile
-          platforms: linux/arm64
+          platforms: linux/arm64,linux/amd64

Dockerfile

@@ -1,13 +1,14 @@
-FROM golang:1.19
+FROM --platform=$BUILDPLATFORM golang:1.19 as builder
 ADD . /usr/src/whereabouts
 RUN mkdir -p $GOPATH/src/github.com/k8snetworkplumbingwg/whereabouts
 WORKDIR $GOPATH/src/github.com/k8snetworkplumbingwg/whereabouts
 COPY . .
-RUN ./hack/build-go.sh
+ARG TARGETOS TARGETARCH
+RUN GOOS=$TARGETOS GOARCH=$TARGETARCH ./hack/build-go.sh
 
 FROM alpine:latest
 LABEL org.opencontainers.image.source https://github.com/k8snetworkplumbingwg/whereabouts
-COPY --from=0 /go/src/github.com/k8snetworkplumbingwg/whereabouts/bin/whereabouts .
-COPY --from=0 /go/src/github.com/k8snetworkplumbingwg/whereabouts/bin/ip-control-loop .
+COPY --from=builder /go/src/github.com/k8snetworkplumbingwg/whereabouts/bin/whereabouts .
+COPY --from=builder /go/src/github.com/k8snetworkplumbingwg/whereabouts/bin/ip-control-loop .
 COPY script/install-cni.sh .
 CMD ["/install-cni.sh"]

Dockerfile.openshift

@@ -1,11 +1,12 @@
 # This dockerfile is used for building for OpenShift
-FROM registry.ci.openshift.org/openshift/release:golang-1.19 as builder
+FROM --platform=$BUILDPLATFORM registry.ci.openshift.org/openshift/release:golang-1.19 as builder
 ADD . /go/src/github.com/k8snetworkplumbingwg/whereabouts
 WORKDIR /go/src/github.com/k8snetworkplumbingwg/whereabouts
-ENV CGO_ENABLED=1
+ENV CGO_ENABLED=0
 ENV GO111MODULE=on
-RUN go build -mod vendor -o bin/whereabouts     cmd/whereabouts.go
-RUN go build -mod vendor -o bin/ip-control-loop cmd/controlloop/controlloop.go
+ARG TARGETARCH TARGETOS
+RUN GOOS=$TARGETOS GOARCH=$TARGETARCH go build -mod vendor -o bin/whereabouts     cmd/whereabouts.go
+RUN GOOS=$TARGETOS GOARCH=$TARGETARCH go build -mod vendor -o bin/ip-control-loop cmd/controlloop/controlloop.go
 WORKDIR /
 
 FROM openshift/origin-base

hack/build-go.sh

@@ -38,6 +38,7 @@ echo "VERSION: ${VERSION}"
 echo "GIT_SHA: ${GIT_SHA}"
 echo "GIT_TREE_STATE: ${GIT_TREE_STATE}"
 echo "RELEASE_STATUS: ${RELEASE_STATUS}"
+echo "PLATFORM: ${GOOS}/${GOARCH}"
 VERSION_LDFLAGS="-X github.com/k8snetworkplumbingwg/whereabouts/pkg/version.Version=${VERSION} \
 -X github.com/k8snetworkplumbingwg/whereabouts/pkg/version.GitSHA=${GIT_SHA} \
 -X github.com/k8snetworkplumbingwg/whereabouts/pkg/version.GitTreeState=${GIT_TREE_STATE} \