name: Docker

# Thanks to Ryan Govostes <https://github.com/rgov> for this workflow.

on:
  push:
    # Publish `master` as Docker `latest` image.
    branches:
      - master

    # Publish `1.2.3` tags as releases.
    tags:
      - '*'

  # Run a test build for any PRs.
  pull_request:

env:
  IMAGE_NAME: mikebrady/shairport-sync
#  DOCKER_PLATFORMS: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
  DOCKER_PLATFORMS: linux/386,linux/amd64,linux/arm/v6,linux/arm64
  DOCKER_HUB_USER: mikebrady

jobs:
  # Build the container image for multiple architectures
  build:
    runs-on: ubuntu-latest

    steps:
      # This unusual setup is due to limitations with `docker buildx`. 
      # See: https://github.com/crazy-max/ghaction-docker-buildx/issues/134
      - name: Prepare
        id: prepare
        run: |
          # Map git ref branch or tag name to Docker tag version
          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
          [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
          [ "$VERSION" == "master" ] && VERSION=latest && SHAIRPORT_SYNC_BRANCH=master
          
          # If tagged with a version, build the same version of Shairport Sync
          [ "$VERSION" != "latest" ] && SHAIRPORT_SYNC_BRANCH=tags/$VERSION

          # Output build arguments for downstream steps
          echo ::set-output name=buildx_args::\
            --platform ${DOCKER_PLATFORMS} \
            --build-arg SHAIRPORT_SYNC_BRANCH=${SHAIRPORT_SYNC_BRANCH} \
            --tag ${IMAGE_NAME}:${VERSION} \
            .

      - uses: actions/checkout@v2
      - uses: crazy-max/ghaction-docker-buildx@v1.2.1

      - name: Build
        run: |
          docker buildx build \
            --output type=image,push=false \
            ${{ steps.prepare.outputs.buildx_args }}

      - name: Log into registry
        if: github.event_name == 'push'
        run: echo "${{ secrets.DOCKER_HUB_TOKEN }}" | docker login --username $DOCKER_HUB_USER --password-stdin

      - name: Push to registry
        if: github.event_name == 'push'
        run: |
          docker buildx build \
            --output type=image,push=true \
            ${{ steps.prepare.outputs.buildx_args }}