pre-build-devcontainer.yml

name: 'build' 
on: # rebuild any PRs and main branch changes
  pull_request:
    branches:
      - main
  push:
    branches:
      - main
  workflow_dispatch: {}
  
jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    env:
      CONTAINER_OWNER: ${{ github.repository_owner }}
      CONTAINER_NAME: ${{ github.event.repository.name }}
    steps:

      - name: Checkout (GitHub)
        uses: actions/checkout@v3

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v2 
        with:
          registry: ghcr.io
          username: ${{ env.CONTAINER_OWNER }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Pre-build dev container image
        uses: devcontainers/ci@v0.3
        with:
          subFolder: .github
          imageName: ghcr.io/${{ env.CONTAINER_OWNER }}/${{ env.CONTAINER_NAME }}
          cacheFrom: ghcr.io/${{ env.CONTAINER_OWNER }}/${{ env.CONTAINER_NAME }}
          push: always