From f97df1c0a84e4326fa60a0af005da2ee57d55237 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miko=C5=82aj=20=C5=9Awi=C4=85tek?=
 <mail+sumo@mikolajswiatek.com>
Date: Tue, 31 Oct 2023 11:59:48 +0100
Subject: [PATCH] Build opamp-bridge on the host

---
 .../publish-operator-opamp-bridge.yaml        | 22 ++++++++++++---
 Makefile                                      |  9 ++++--
 cmd/operator-opamp-bridge/Dockerfile          | 28 ++++++-------------
 3 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/.github/workflows/publish-operator-opamp-bridge.yaml b/.github/workflows/publish-operator-opamp-bridge.yaml
index 8493d37472..c5833b554d 100644
--- a/.github/workflows/publish-operator-opamp-bridge.yaml
+++ b/.github/workflows/publish-operator-opamp-bridge.yaml
@@ -11,18 +11,35 @@ on:
       - 'v*'
   workflow_dispatch:
 
+env:
+  PLATFORMS: linux/amd64,linux/arm64,linux/s390x,linux/ppc64le
+
 jobs:
   publish:
     runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4
+      
+      - uses: actions/setup-go@v4
+        with:
+          go-version: '~1.21.3'
+          cache-dependency-path: 'cmd/operator-opamp-bridge/go.sum'
 
+      # TODO: We're currently not using this. Should we?
       - name: Read version
         run: |
           echo "VERSION=$(git describe --tags | sed 's/^v//')" >> $GITHUB_ENV
           echo "VERSION_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> $GITHUB_ENV
 
+      - name: Build the binary for each supported architecture
+        run: |
+          for platform in $(echo $PLATFORMS | tr "," "\n"); do
+            arch=${platform#*/}
+            echo "Building operator-opamp-bridge for $arch"
+            make operator-opamp-bridge ARCH=$arch
+          done
+
       - name: Docker meta
         id: meta
         uses: docker/metadata-action@v5
@@ -69,11 +86,8 @@ jobs:
         uses: docker/build-push-action@v5
         with:
           context: cmd/operator-opamp-bridge
-          platforms: linux/amd64,linux/arm64,linux/s390x,linux/ppc64le
+          platforms: ${{ env.PLATFORMS }}
           push: true
-          build-args: |
-            VERSION=${{ env.VERSION }}
-            VERSION_DATE=${{ env.VERSION_DATE }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=local,src=/tmp/.buildx-cache
diff --git a/Makefile b/Makefile
index 863009f04c..5c04861dd8 100644
--- a/Makefile
+++ b/Makefile
@@ -108,6 +108,10 @@ test: generate fmt vet ensure-generate-is-noop envtest
 manager: generate fmt vet
 	go build -o bin/manager main.go
 
+# Build opamp bridge binary
+operator-opamp-bridge:
+	cd cmd/operator-opamp-bridge && CGO_ENABLED=0 GOOS=$(GOOS) GOARCH=$(ARCH) go build -a -installsuffix cgo -o bin/opampbridge_${ARCH} .
+
 # Run against the configured Kubernetes cluster in ~/.kube/config
 .PHONY: run
 run: generate fmt vet manifests
@@ -257,8 +261,9 @@ container-target-allocator:
 	docker buildx build  --load --platform linux/${ARCH} -t ${TARGETALLOCATOR_IMG} cmd/otel-allocator
 
 .PHONY: container-operator-opamp-bridge
-container-operator-opamp-bridge:
-	docker buildx build --platform linux/${ARCH} -t ${OPERATOROPAMPBRIDGE_IMG} cmd/operator-opamp-bridge
+container-operator-opamp-bridge: GOOS = linux
+container-operator-opamp-bridge: operator-opamp-bridge
+	docker build -t ${OPERATOROPAMPBRIDGE_IMG} cmd/operator-opamp-bridge
 
 .PHONY: start-kind
 start-kind:
diff --git a/cmd/operator-opamp-bridge/Dockerfile b/cmd/operator-opamp-bridge/Dockerfile
index 0ec1b6581d..ae8a861b89 100644
--- a/cmd/operator-opamp-bridge/Dockerfile
+++ b/cmd/operator-opamp-bridge/Dockerfile
@@ -1,29 +1,19 @@
-# Build the operator-opamp-bridge binary
-FROM golang:1.21-alpine as builder
-
-WORKDIR /app
+# Get CA certificates from the Alpine package repo
+FROM alpine:3.18 as certificates
 
 RUN apk --no-cache add ca-certificates
 
-# Copy go mod and sum files
-COPY go.mod go.sum ./
-
-RUN go mod download
-
-COPY . .
-
-# Build the Go app
-RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .
-
-######## Start a new stage from scratch #######
+# Start a new stage from scratch
 FROM scratch
 
+ARG TARGETARCH
+
 WORKDIR /root/
 
-# Copy the certs from the builder
-COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+# Copy the certs
+COPY --from=certificates /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 
-# Copy the pre-built binary file from the previous stage
-COPY --from=builder /app/main .
+# Copy binary built on the host
+COPY bin/opampbridge_${TARGETARCH} ./main
 
 ENTRYPOINT ["./main"]