Add GitHub Actions CI/CD with multi-arch builds

.github/workflows/build.yml

@@ -0,0 +1,55 @@
+name: Build & Deploy
+
+on:
+  push:
+    branches: [ 'master' ]
+  pull_request:
+    branches: [ 'master' ]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  docker:
+    name: Build and push docker
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: install GitVersion
+        uses: gittools/actions/gitversion/setup@v0.11.0
+        with:
+          versionSpec: '5.x'
+      - name: determine version
+        id: gitversion
+        uses: gittools/actions/gitversion/execute@v0.11.0
+      - name: set up QEMU
+        uses: docker/setup-qemu-action@v2
+      - name: set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: login to GHCR
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/changemakerstudios/agent
+          tags: |
+            type=raw,value=${{ steps.gitversion.outputs.semVer }}
+            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/master' }}
+      - name: build and push
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          platforms: linux/amd64,linux/arm64/v8,linux/arm/v7,linux/arm/v5
+          tags: ${{ steps.meta.outputs.tags }}

Dockerfile

@@ -1,17 +1,21 @@
-FROM golang:1.25 AS builder
+FROM --platform=$BUILDPLATFORM golang:1.25 AS builder
+
+ARG TARGETOS
+ARG TARGETARCH
+ARG TARGETVARIANT
 
 WORKDIR /build
 
 ENV CGO_ENABLED=0
-ARG GOOS=linux
-ARG GOARCH=amd64
-ARG GOARM
 
-COPY . /build/
-RUN go build -a -installsuffix cgo -o agent .
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} GOARM=${TARGETVARIANT#v} \
+    go build -a -installsuffix cgo -o agent .
 
 FROM scratch
-MAINTAINER Pavol Noha <pavol.noha@gmail.com>
 EXPOSE 8080
 WORKDIR /
 COPY --from=builder /build/agent /