build.yaml

# Name your workflow
name: build

# Set on which events you want run the actions.
# In this case the workflow will run on push for master and on pull request for master and develop branches
on:
  push:
    branches:
      - '*'
      - '!matcher'

  pull_request:
    branches:
      - '*'         # matches every branch that doesn't contain a '/'
      - '*/*'       # matches every branch containing a single '/'
      - '**'        # matches every branch

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Log in to the Container registry
        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      -
        # Setting up Docker Buildx with docker-container driver is required
        # at the moment to be able to use a subdirectory with Git context
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      - name: Build and push Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max