A sample GitHub Action file for container builds

build.yml

name: container-build

on:
  push:
    branches: [ main ]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ACCOUNT/IMAGE-NAME        # replace these as needed
  IMAGE_TAG: 1.${{ github.run_number }} # GITHUB_RUN_NUMBER, so versions will be 1.1, 1.2, etc.
  DOCKER_BUILDKIT: 1

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GHCR_PAT }}

      - name: Build and Push
        uses: docker/build-push-action@v5
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          provenance: false
          push: ${{ github.event_name != 'pull_request' }}
          tags: |
            ghcr.io/${{ env.IMAGE_NAME }}:${{ env.IMAGE_TAG }}
            ghcr.io/${{ env.IMAGE_NAME }}:latest
          labels: ${{ steps.meta.outputs.labels }}

      - name: Image digest
        run: echo ${{ steps.docker_build.outputs.digest }}