# ref: https://blog.oddbit.com/post/2020-09-25-building-multi-architecture-im/

name: Docker

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

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - name: Prepare
      id: prepare
      run: |
        DOCKER_IMAGE=${{ secrets.DOCKER_IMAGE }}
        VERSION=latest
        SHORTREF=${GITHUB_SHA::8}

        # If this is git tag, use the tag name as a docker tag
        if [[ $GITHUB_REF == refs/tags/* ]]; then
          VERSION=${GITHUB_REF#refs/tags/v}
        fi
        TAGS="${DOCKER_IMAGE}:${VERSION},${DOCKER_IMAGE}:${SHORTREF}"

        # If the VERSION looks like a version number, assume that
        # this is the most recent version of the image and also
        # tag it 'latest'.
        if [[ $VERSION =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
          TAGS="$TAGS,${DOCKER_IMAGE}:latest"
        fi

        # Set output parameters.
        echo ::set-output name=tags::${TAGS}
        echo ::set-output name=docker_image::${DOCKER_IMAGE}

      # https://github.com/actions/checkout
    - name: Checkout
      uses: actions/checkout@v2

    - name: Docker Login
      if: github.event_name != 'pull_request'
      uses: docker/login-action@v1
      with:
        username: ${{ secrets.DOCKER_USERNAME }}
        password: ${{ secrets.DOCKER_PASSWORD }}
    
    - name: Set up Docker Buildx
      id: buildx
      uses: docker/setup-buildx-action@v1
    
    - name: Environment
      run: |
        echo home=$HOME
        echo git_ref=$GITHUB_REF
        echo git_sha=$GITHUB_SHA
        echo image=${{ steps.prepare.outputs.docker_image }}
        echo tags=${{ steps.prepare.outputs.tags }}
        echo avail_platforms=${{ steps.buildx.outputs.platforms }}

    - name: Build and push
      uses: docker/build-push-action@v2
      with:
        builder: ${{ steps.buildx.outputs.name }}
        context: .
        file: ./Dockerfile
        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8
        push: true
        tags: ${{ steps.prepare.outputs.tags }}