factorio-docker/.github/workflows/docker_push.yml

name: Docker build & push

on:
  push:
    branches:
      - master

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v2
      - name: build and push
        if: ${{ env.DOCKER_USERNAME != '' && env.DOCKER_PASSWORD != '' }}
        env:
          DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
        run: |
          ./build.py --push-tags