GitHub ActionsでDocker RegistryにDockerイメージをpushする（latestタグ、GitHub Release連携でバージョン付け）

• https://blog.aoirint.com/entry/2021/github_actions_docker_io_token/

上の記事のWorkflowテンプレートをちょっと改良した。

• Docker Hub以外のDockerレジストリに対応
• GitHub Release作成時にリリースタグをイメージタグにしてpush

レジストリURL

• Docker Hub: docker.io
• GitHub Container Registry: ghcr.io
• GitLab Container Registry: registry.gitlab.com

GitHub Secrets

• DOCKER_USERNAME
• DOCKER_TOKEN

GitHub Workflow .github/workflows/docker.yml

• https://github.com/docker/login-action
• https://github.com/docker/build-push-action

name: Push to Docker registry

on:
  push:
    branches:
      - main
  release:
    types:
      - created

env:
  IMAGE_NAME: docker.io/username/imagename
  IMAGE_TAG: ${{ github.event.release.tag_name != '' && github.event.release.tag_name || 'latest' }}

jobs:
  push:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      
      - name: Setup Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v2

      - name: Login to Docker Registry
        uses: docker/login-action@v2
        with:
          registry: docker.io
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_TOKEN }}

      - name: Build and Deploy Docker image
        uses: docker/build-push-action@v3
        env:
          IMAGE_NAME_AND_TAG: ${{ format('{0}:{1}', env.IMAGE_NAME, env.IMAGE_TAG) }}
        with:
          context: .
          builder: ${{ steps.buildx.outputs.name }}
          file: ./Dockerfile
          push: true
          tags: ${{ env.IMAGE_NAME_AND_TAG }}
          cache-from: type=registry,ref=${{ env.IMAGE_NAME_AND_TAG }}-buildcache
          cache-to: type=registry,ref=${{ env.IMAGE_NAME_AND_TAG }}-buildcache,mode=max