Add GitHub Actions workflow for release process

Author: zeroalphat

.github/release.yml

@@ -0,0 +1,30 @@
+changelog:
+  exclude:
+    labels:
+      - ignore-for-release
+      - ci
+      - documentation
+      - refactoring
+      - test
+  categories:
+    - title: Features
+      labels:
+        - enhancement
+    - title: Bug Fixes
+      labels:
+        - bug
+    - title: Deprecated
+      labels:
+        - deprecate
+    - title: Removed
+      labels:
+        - remove
+    - title: Security
+      labels:
+        - security
+    - title: Dependencies
+      labels:
+        - dependencies
+    - title: Others
+      labels:
+        - "*"

.github/workflows/release.yaml

@@ -0,0 +1,62 @@
+name: Release
+on:
+  push:
+    tags:
+      - "v*"
+jobs:
+  image-build:
+    name: Push Container Image
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      packages: write 
+    steps:
+      - uses: actions/checkout@v4
+      - name: Get version
+        id: get_version
+        run: |
+          version=${GITHUB_REF#refs/tags/v}
+          echo "result=${version}" >> $GITHUB_OUTPUT
+      - uses: docker/setup-qemu-action@v3
+        with:
+          platforms: linux/amd64
+      - uses: docker/setup-buildx-action@v3
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build and push ofen image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: dockerfiles/Dockerfile.imageprefetch-controller 
+          push: ${{ github.ref_name == 'main'}}
+          tags: |
+            ghcr.io/cybozu-go/ofen:${{steps.get_version.outputs.result}})
+      - name: Build and push ofend image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: dockerfiles/Dockerfile.nodeimageset-controller
+          push: ${{ github.ref_name == 'main'}}
+          tags: |
+            ghcr.io/cybozu-go/ofend:${{steps.get_version.outputs.result}}
+  release:
+    name: Release on GitHub
+    needs: image-build
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+      - name: Create Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          VERSION=${GITHUB_REF#refs/tags/} # Don't remove "v" prefix.
+          if echo ${VERSION} | grep -q -e '-'; then PRERELEASE_FLAG=-p; fi
+          gh release create $VERSION $PRERELEASE_FLAG \
+            -t "Release $VERSION"  \
+            --generate-notes 

CHANGELOG.md

@@ -3,30 +3,15 @@ Release procedure
 
 This document describes how to release a new version.
 
-## Versioning
-
-Follow [semantic versioning 2.0.0][semver] to choose the new version number.
-
-## Prepare change log entries
-
-Add notable changes since the last release to [CHANGELOG.md](CHANGELOG.md).
-It should look like:
+## Labeling
 
-```markdown
-(snip)
-## [Unreleased]
+Release notes are automatically generated based on PRs included in the release.
+Those PRs are categorized based on the label assigned to them.
+Please refer to `.github/release.yml` for the kind of labels.
 
-### Added
-- Implement ... (#35)
-
-### Changed
-- Fix a bug in ... (#33)
-
-### Removed
-- Deprecated `-option` is removed ... (#39)
+## Versioning
 
-(snip)
-```
+Follow [semantic versioning 2.0.0][semver] to choose the new version number.
 
 ## Bump version
 
@@ -38,25 +23,7 @@ It should look like:
     $ echo $VERSION
     ```
 
-2. Make a branch to release
-
-    ```console
-    $ git checkout main
-    $ git pull
-    $ git checkout -b "bump-$VERSION"
-    ```
-
-3. Edit `CHANGELOG.md` for the new version ([example][]).
-4. Commit the change and push it.
-
-    ```console
-    $ git commit -a -m "Bump version to $VERSION"
-    $ git push -u origin HEAD
-    $ gh pr create -f
-    ```
-
-5. Merge this branch.
-6. Add a git tag to the main HEAD, then push it.
+2. Add a git tag to the main HEAD, then push it.
 
     ```console
     # Set VERSION again.
@@ -77,4 +44,3 @@ GitHub actions will build and push artifacts such as container images and
 create a new GitHub release.
 
 [semver]: https://semver.org/spec/v2.0.0.html
-[example]: https://github.com/cybozu-go/etcdpasswd/commit/77d95384ac6c97e7f48281eaf23cb94f68867f79