ci: Publish distribution files to PyPI

Add steps to publish distribution files to PyPI when a tag is created.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

.github/workflows/ci.yaml

@@ -32,3 +32,49 @@ jobs:
     - name: run nox
       run: nox
       timeout-minutes: 10
+
+  build-dist:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Fetch sources
+        uses: actions/checkout@v3
+        with:
+          submodules: true
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+
+      - name: Install build dependencies
+        run: |
+          python -m pip install -U pip
+          python -m pip install -U build
+
+      - name: Build the source and binary distribution
+        run: python -m build
+
+      - name: Upload dist files
+        uses: actions/upload-artifact@v3
+        with:
+          name: frequenz-channels-python-dist
+          path: dist/
+          if-no-files-found: error
+
+  publish-to-pypi:
+    needs: ["test", "build-dist"]
+    # Publish only on tags creation
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Download dist files
+        uses: actions/download-artifact@v3
+        with:
+          name: frequenz-channels-python-dist
+
+      - name: Publish the Python distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}
+          packages_dir: ./
+          skip_existing: true