build-and-push.yaml

name: Build and push container image
# try to follow the example here:  https://gist.github.com/Daniel-ltw/552b90800b07c22e4a83dfa68ada6318
on:
  push:
    branches:
      - main

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    env:
      DOCKER_CONFIG: $HOME/.docker
      HUB: ${{ vars.HUB }}
      IMAGE: ${{ vars.IMAGE }}
    outputs:
      image-tag: ${{ steps.build-and-push.outputs.image-tag }}

    steps:
      - name: cleanup disk space
        run: |
          sudo rm -rf /usr/local/lib/android /usr/share/dotnet /opt/ghc
          df -h

      - name: Display the image and hub names
        run: |
          echo "$IMAGE"
          echo "$HUB"

      - name: Check out the repo
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # OR "2" -> To retrieve the preceding commit.

      - name: Get changed files
        id: changed-files
        uses: tj-actions/changed-files@v44
        with:
          files_ignore: |
            .github/**
            images/**

      - name: Log in to GAR
        if: steps.changed-files.outputs.any_changed == 'true'
        uses: docker/login-action@v1
        with:
          registry: us-central1-docker.pkg.dev
          username: _json_key
          password: ${{ secrets.GAR_SECRET_KEY }}

      - name: Build the image and push to artifact registry
        id: build-and-push
        if: steps.changed-files.outputs.any_changed == 'true'
        uses: jupyterhub/repo2docker-action@master
        with:
          # Make sure username & password/token pair matches your registry credentials
          DOCKER_REGISTRY: us-central1-docker.pkg.dev
          IMAGE_NAME: $IMAGE
          # Disable pushing a 'latest' tag, as this often just causes confusion
          LATEST_TAG_OFF: true
          # Put repo contents in /srv/repo, rather than the default (/home/jovyan). The home directory
          # is mounted over by persistent storage when we are using the built image in a JupyterHub, and
          # so all contents put in /home/jovyan are lost. This particularly prevents any 'start' script from
          # working, as it is needed in runtime.
          REPO_DIR: /srv/repo

      - name: print the image name
        run: |
          echo ${{ steps.build-and-push.outputs.IMAGE_SHA_TAG }}

      - name: Save image tag as an artifact
        run: echo ${{ steps.build-and-push.outputs.IMAGE_SHA_TAG }} > image-tag.txt
      - uses: actions/upload-artifact@v4
        with:
          name: image-tag
          path: ./image-tag.txt
          compression-level: 0

      # Lets us monitor disks getting full as images get bigger over time
      - name: Show how much disk space is left
        run: df -h