build-devcontainer.yml

name: Build Devcontainer

on:
  push:
    branches: [main]
    paths:
      - '.devcontainer/Dockerfile'
      - 'pyproject.toml'
      - '.github/workflows/build-devcontainer.yml'
  pull_request:
    paths:
      - '.devcontainer/Dockerfile'
      - 'pyproject.toml'
      - '.github/workflows/build-devcontainer.yml'
  workflow_dispatch:

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6

      - name: Compute image path
        id: image
        run: |
          repo_lower=$(echo '${{ github.repository }}' | tr '[:upper:]' '[:lower:]')
          echo "name=ghcr.io/$repo_lower/devcontainer:latest" >> $GITHUB_OUTPUT
          echo "repo_lower=$repo_lower" >> $GITHUB_OUTPUT

      - name: Log in to GitHub Container Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build devcontainer image (PR)
        if: github.event_name == 'pull_request'
        uses: docker/build-push-action@v6
        with:
          context: .
          file: .devcontainer/Dockerfile
          push: false
          tags: ${{ steps.image.outputs.name }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Build and push devcontainer image (main)
        if: github.event_name != 'pull_request'
        uses: docker/build-push-action@v6
        with:
          context: .
          file: .devcontainer/Dockerfile
          push: true
          tags: ${{ steps.image.outputs.name }}
          cache-from: |
            type=registry,ref=ghcr.io/${{ steps.image.outputs.repo_lower }}/devcontainer:cache
            type=registry,ref=ghcr.io/${{ steps.image.outputs.repo_lower }}/devcontainer:latest
          cache-to: type=registry,ref=ghcr.io/${{ steps.image.outputs.repo_lower }}/devcontainer:cache,mode=max