ci: set up docker image build workflow (#89)

Fixes #27

.github/templates/.release_notes.md.j2

@@ -3,8 +3,17 @@
 ## Release Notes
 {% include ".changes.j2" %}
 {{ "**Full Changelog**: (%s)" | format(prev_version | compare_url(version)) }}
+
 ## Installation
+
 You can install this version via pip from [PyPI](https://pypi.org/project/python-re3data/{{ version }}/):
+
 ```console
 python -m pip install python-re3data=={{ version }}
 ```
+
+or pull the Docker image from [ghcr.io](https://github.com/afuetterer/python-re3data/pkgs/container/python-re3data):
+
+```console
+docker pull ghcr.io/afuetterer/python-re3data:{{ version }}
+```

.github/workflows/publish.yml

@@ -38,3 +38,45 @@ jobs:
         path: dist
     - name: Publish package to PyPI
       uses: pypa/gh-action-pypi-publish@81e9d935c883d0b210363ab89cf05f3894778450 # v1.8.14
+
+  docker:
+    name: Publish Docker image to ghcr.io
+    # disables this workflow from running in a repository that is not part of the indicated organization/user
+    if: github.repository_owner == 'afuetterer'
+    runs-on: ubuntu-24.04
+    needs: build
+    permissions:
+      contents: read
+      packages: write
+    env:
+      IMAGE_NAME: ${{ github.repository }}
+    steps:
+    - uses: docker/setup-buildx-action@d70bba72b1f3fd22344832f00baa16ece964efeb # v3.3.0
+    - name: Login to GitHub Container Registry
+      uses: docker/login-action@0d4c9c5ea7693da7b068278f7b52bda2a190a446 # v3.2.0
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+    - name: Generate Docker image metadata
+      id: meta
+      # Ref: https://github.com/docker/metadata-action?tab=readme-ov-file#customizing
+      uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81 # v5.5.1
+      with:
+        images: ghcr.io/${{ env.IMAGE_NAME }}
+        flavor: latest=true
+        tags: |
+          type=pep440,pattern={{version}}
+          type=pep440,pattern={{major}}.{{minor}}
+    - name: Build and push image to registry
+      # Ref: https://github.com/docker/build-push-action?tab=readme-ov-file#customizing
+      uses: docker/build-push-action@2cdde995de11925a030ce8070c3d77a52ffcf1c0 # v5.3.0
+      with:
+        push: true
+        build-args: VERSION=${{ github.event.release.name }}
+        cache-from: type=gha
+        cache-to: type=gha,mode=max
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}
+        # Ref: https://docs.docker.com/build/attestations/slsa-provenance/
+        provenance: false

README.md

@@ -69,6 +69,12 @@ You can install `python-re3data` via pip from [PyPI][pypi-url]:
 python -m pip install python-re3data
 ```
 
+or pull the Docker image from [ghcr.io](https://github.com/afuetterer/python-re3data/pkgs/container/python-re3data):
+
+```console
+docker pull ghcr.io/afuetterer/python-re3data:latest
+```
+
 ## Documentation
 
 The [documentation][docs-url] is made with [Material for MkDocs](https://github.com/squidfunk/mkdocs-material) and is