Fix: multiarch build by using crosscompilation

.github/workflows/image-build-test.yaml

@@ -27,9 +27,5 @@ jobs:
         with:
           context: .
           push: false
-          # no need to explicitly set goarch, 
-          # correct arch will be selected for each build platform 
-          build-args: |
-            goarch=
           platforms: ${{ env.BUILD_PLATFORMS }}
           file: ./cmd/Dockerfile

.github/workflows/image-push-main.yaml

@@ -45,10 +45,6 @@ jobs:
         with:
           context: .
           push: true
-          # no need to explicitly set goarch, 
-          # correct arch will be selected for each build platform 
-          build-args: |
-            goarch=
           platforms: ${{ env.BUILD_PLATFORMS }}
           tags: |
             ${{ env.IMAGE_NAME }}:latest

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

@@ -47,10 +47,6 @@ jobs:
         with:
           context: .
           push: true
-          # no need to explicitly set goarch, 
-          # correct arch will be selected for each build platform 
-          build-args: |
-            goarch=
           platforms: ${{ env.BUILD_PLATFORMS }}
           tags: |
             ${{ steps.docker_meta.outputs.tags }}

Makefile

@@ -13,7 +13,7 @@ export GOROOT=$(BIN_DIR)/go/
 export GOBIN = $(GOROOT)/bin/
 export PATH := $(GOBIN):$(PATH):$(BIN_DIR)
 GOPATH = $(CURDIR)/.gopath
-GOARCH ?= amd64
+GOARCH ?= $(shell uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/')
 ORG_PATH = github.com/k8snetworkplumbingwg
 PACKAGE = ovs-cni
 OCI_BIN ?= $(shell if podman ps >/dev/null 2>&1; then echo podman; elif docker ps >/dev/null 2>&1; then echo docker; fi)

cmd/Dockerfile

@@ -1,27 +1,42 @@
-FROM quay.io/centos/centos:stream9 as builder
+FROM --platform=$BUILDPLATFORM quay.io/centos/centos:stream9 AS builder
 
 RUN mkdir /workdir
-WORKDIR /workdir
+# Support overriding target GOARCH during `make docker-build`
+ARG goarch=
 
-COPY go.mod .
+# these variable are automatically set during the multiarch build by docker buildx
+ARG TARGETOS
+ARG TARGETARCH
+ENV TARGETOS=${TARGETOS:-linux}
+ENV TARGETARCH=${TARGETARCH:-amd64}
+
+ARG BUILDOS
+ARG BUILDARCH
+ENV BUILDOS=${BUILDOS:-linux}
+ENV BUILDARCH=${BUILDARCH:-amd64}
+
+ENV GOOS=${TARGETOS}
+ENV GOARCH=${goarch:-$TARGETARCH}
+ENV CGO_ENABLED=0
+ENV GOFLAGS=-mod=vendor
+
+WORKDIR /workdir
 
 RUN dnf install -y wget
 
+COPY go.mod .
+COPY go.sum .
+
 RUN GO_VERSION=$(sed -En 's/^go +(.*)$/\1/p' go.mod) && \
-    wget https://dl.google.com/go/go${GO_VERSION}.linux-amd64.tar.gz && \
-    tar -C /usr/local -xzf go${GO_VERSION}.linux-amd64.tar.gz && \
-    rm go${GO_VERSION}.linux-amd64.tar.gz
+    wget https://dl.google.com/go/go${GO_VERSION}.${BUILDOS}-${BUILDARCH}.tar.gz && \
+    tar -C /usr/local -xzf go${GO_VERSION}.${BUILDOS}-${BUILDARCH}.tar.gz && \
+    rm go${GO_VERSION}.${BUILDOS}-${BUILDARCH}.tar.gz
 
-ENV PATH /usr/local/go/bin:$PATH
+ENV PATH=/usr/local/go/bin:$PATH
 
-COPY . .
+RUN go mod download
 
-ENV GOOS linux
-# Support overriding target GOARCH during `make docker-build`
-ARG goarch=amd64
-ENV GOARCH=$goarch
-ENV CGO_ENABLED 0
-ENV GOFLAGS -mod=vendor
+COPY . .
 
 RUN mkdir /workdir/bin
 RUN go build -tags no_openssl -o /workdir/bin/ovs ./cmd/plugin
@@ -30,6 +45,8 @@ RUN go build -tags no_openssl -o /workdir/bin/ovs-mirror-producer ./cmd/mirror-p
 RUN go build -tags no_openssl -o /workdir/bin/ovs-mirror-consumer ./cmd/mirror-consumer
 
 FROM registry.access.redhat.com/ubi9/ubi-minimal
+
 RUN microdnf install -y findutils
+
 COPY --from=builder /workdir/.version /.version
 COPY --from=builder /workdir/bin/* /