# ref: https://docs.docker.com/ci-cd/github-actions/
# https://blog.oddbit.com/post/2020-09-25-building-multi-architecture-im/

name: docker

on:
  push:
    branches:
    - master
    tags:
    - 'v*'

permissions:
  contents: read

# New pushes cancel an in-progress build for the same ref. Tags are isolated
# by ref, so re-pushing a release tag only de-dupes itself, never another tag.
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

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

    # Auto-generates image tags, replacing the former hand-rolled shell:
    #   - master push                         -> :latest
    #   - clean release tag vX.Y.Z             -> :X.Y.Z :X :X.Y :latest
    #   - nightly tag vX.Y.Z-nightly.<date>    -> :X.Y.Z-nightly.<date>   (no major/minor/latest)
    - name: Docker meta
      id: meta
      uses: docker/metadata-action@v5
      with:
        images: ${{ secrets.DOCKER_IMAGE }}
        flavor: latest=false
        tags: |
          type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) || (startsWith(github.ref, 'refs/tags/v') && !contains(github.ref_name, '-')) }}
          type=semver,pattern={{version}}
          type=semver,pattern={{major}},enable=${{ !contains(github.ref_name, '-') }}
          type=semver,pattern={{major}}.{{minor}},enable=${{ !contains(github.ref_name, '-') }}

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

    - name: Login to DockerHub
      if: github.event_name != 'pull_request'
      uses: docker/login-action@v3
      with:
        username: ${{ secrets.DOCKER_USERNAME }}
        password: ${{ secrets.DOCKER_PASSWORD }}

    - name: Buildx and push
      uses: docker/build-push-action@v6
      with:
        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/s390x,linux/riscv64
        push: true
        tags: ${{ steps.meta.outputs.tags }}
        # Reuse build layers across runs via the GitHub Actions cache.
        cache-from: type=gha
        cache-to: type=gha,mode=max