Enable automatic release on tag

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

.github/workflows/pypi-release.yml

@@ -1,27 +1,83 @@
-name: Release library as a PyPI wheel and sdist on GH release creation
+name: Create library release archives, create a GH release and publish PyPI wheel and sdist on tag in main branch
+
+
+# This is executed automatically on a tag in the main branch
+
+# Summary of the steps:
+# - build wheels and sdist
+# - upload wheels and sdist to PyPI
+# - create gh-release and upload wheels and dists there
+# TODO: smoke test wheels and sdist
+# TODO: add changelog to release text body
+
+# WARNING: this is designed only for packages building as pure Python wheels
 
 on:
-  release:
-    types: [created]
+  workflow_dispatch:
+  push:
+    tags:
+      - "v*.*.*"
 
 jobs:
-  build-and-publish-to-pypi:
+  build-pypi-distribs:
     name: Build and publish library to PyPI
     runs-on: ubuntu-20.04
+
+    steps:
+      - uses: actions/checkout@master
+      - name: Set up Python
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.9
+
+      - name: Install pypa/build
+        run: python -m pip install build --user
+
+      - name: Build a binary wheel and a source tarball
+        run: python -m build --sdist --wheel --outdir dist/
+
+      - name: Upload built archives
+        uses: actions/upload-artifact@v3
+        with:
+          name: pypi_archives
+          path: dist/*
+
+
+  create-gh-release:
+    name: Create GH release
+    needs:
+      - build-pypi-distribs
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Download built archives
+        uses: actions/download-artifact@v3
+        with:
+          name: pypi_archives
+          path: dist
+
+      - name: Create GH release
+        uses: softprops/action-gh-release@v1
+        with:
+          draft: true
+          files: dist/*
+
+
+  create-pypi-release:
+    name: Create PyPI release
+    needs:
+      - create-gh-release
+    runs-on: ubuntu-20.04
+
     steps:
-     - uses: actions/checkout@master
-     - name: Set up Python
-       uses: actions/setup-python@v1
-       with:
-         python-version: 3.9
-     - name: Install pypa/build
-       run: python -m pip install build --user
-     - name: Build a binary wheel and a source tarball
-       run: python -m build --sdist --wheel --outdir dist/
-        .
-     - name: Publish distribution  to PyPI
-       if: startsWith(github.ref, 'refs/tags')
-       uses: pypa/gh-action-pypi-publish@master
-       with:
-         password: ${{ secrets.PYPI_API_TOKEN }}
-        
+      - name: Download built archives
+        uses: actions/download-artifact@v3
+        with:
+          name: pypi_archives
+          path: dist
+
+      - name: Publish to PyPI
+        if: startsWith(github.ref, 'refs/tags')
+        uses: pypa/gh-action-pypi-publish@master
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}