build: create releases with Release Please

resolves #346

.github/workflows/release.yml

@@ -0,0 +1,61 @@
+name: Release SILO
+
+on:
+  workflow_run:
+    workflows: [LAPIS-SILO]
+    types: [completed]
+    branches: [main]
+
+env:
+  DOCKER_IMAGE_NAME: ghcr.io/genspectrum/lapis-silo
+
+jobs:
+  release-please:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+      packages: write
+    if: ${{ github.event.workflow_run.conclusion == 'success' && github.repository == 'GenSpectrum/LAPIS-SILO' }}
+    steps:
+      - uses: google-github-actions/release-please-action@v4
+        id: release
+        with:
+          path: .
+          config-file: release-please-config.json
+          manifest-file: .release-please-manifest.json
+          target-branch: main
+
+      - name: Inspect Release Outputs
+        run: |
+          cat <<'EOF'
+          ${{ toJson(steps.release.outputs) }}
+          EOF
+
+      - uses: actions/checkout@v4
+        if: ${{ steps.release.outputs.release_created }}
+
+      - name: Set up Docker Buildx
+        if: ${{ steps.release.outputs.release_created }}
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GitHub Container Registry
+        if: ${{ steps.release.outputs.release_created }}
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Tag Already Built Images With Release Tags
+        if: ${{ steps.release.outputs.release_created }}
+        run: |
+          MAJOR=${{ steps.release.outputs.major }}
+          MINOR=${{ steps.release.outputs.minor }}
+          PATCH=${{ steps.release.outputs.patch }}
+          TAGS=("$MAJOR.$MINOR" "$MAJOR.$MINOR.$PATCH")
+          # TODO (#405) include $MAJOR only for releases >= 1.0
+          # TAGS=("$MAJOR" "$MAJOR.$MINOR" "$MAJOR.$MINOR.$PATCH")
+          for TAG in "${TAGS[@]}"; do
+            docker buildx imagetools create --tag $DOCKER_IMAGE_NAME:$TAG $DOCKER_IMAGE_NAME:latest
+          done

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+    ".": "0.0.1"
+}

README.md

@@ -131,7 +131,7 @@ docker run
 
 The directory where SILO expects the preprocessing output can be overwritten via
 `silo --api --dataDirectory=/custom/data/directory` or in a corresponding
-configuration [configuration file](#configuration-files).
+[configuration file](#configuration-files).
 
 ### Notes On Building The Image
 
@@ -141,6 +141,22 @@ Docker will cache layers, and it will cache the dependencies built by Conan via
 However, cache mounts don't work in GitHub Actions (https://github.com/docker/build-push-action/issues/716),
 so there we only rely on Docker's layer cache via Docker's gha cache backend.
 
+## Creating A Release
+
+This project uses [Release Please](https://github.com/google-github-actions/release-please-action) to generate releases.
+On every commit on the `main` branch, it will update a Pull Request with a changelog.
+When the PR is merged, the release will be created.
+Creating a release means:
+
+* A new Git tag is created.
+* The Docker images of SILO are tagged with the new version.
+  * Suppose the created version is `2.4.5`, then it creates the tags `2`, `2.4` and `2.4.5` on the current `latest` image.
+
+The changelog and the version number are determined by the commit messages.
+Therefore, commit messages should follow the [Conventional Commits](https://www.conventionalcommits.org/) specification.
+Also refer to the Release Please documentation for more information on how to write commit messages
+or see [Conventional Commits](#conventional-commits) below.
+
 # Testing
 
 ## Unit Tests

release-please-config.json

@@ -0,0 +1,9 @@
+{
+    "packages": {
+        ".": {
+            "release-type": "simple"
+        }
+    },
+    "bump-minor-pre-major": true,
+    "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
+}

version.txt

@@ -0,0 +1 @@
+0.0.1