Example of GitHub Action to build and push Docker images to GitHub Registry

docker-publish.yml

name: Build and publish development Docker image

on:
  push:
    tags:
      - 'v*.*.*'

jobs:
  docker-build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Set env
        run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
        # @CHECKME: OR use this? run: echo ::set-env name=RELEASE_VERSION::$(echo ${GITHUB_REF#refs/*/})
      - name: Login to GitHub Container Registry
        uses: docker/login-action@v1
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push docker image
        uses: docker/build-push-action@v2
        with:
          context: .
          push: true
          tags: |
            ghcr.io/OWNER/IMAGE_NAME:latest
            ghcr.io/OWNER/IMAGE_NAME:${{ env.RELEASE_VERSION }}