Build and publish Docker train image on tag

.github/workflows/build-and-test.yml

@@ -828,6 +828,36 @@ jobs:
           EOF
       - run: |
           twine upload --repository pypi *.whl
+  docker-publish:
+    name: "Build and publish Docker training image to GHCR"
+    runs-on: ubuntu-20.04
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+          submodules: 'recursive'
+      - name: Log in to the Container registry
+        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Check VERSION matches Git tag and compute Docker tag
+        id: compute-tag
+        run: |
+          VERSION="v$(cat VERSION)"
+          if [[ "${{ github.ref }}" != "refs/tags/${VERSION}" ]]; then
+            echo "Pushed tag does not match VERSION file. Aborting push."
+            exit 1
+          fi
+          echo "::set-output name=tag::${VERSION}"
+      - name: Build and push
+        run: |
+          DOCKER_TAG="${{ steps.compute-tag.outputs.tag }}"
+          docker build -f Dockerfile.train . -t ghcr.io/coqui-ai/stt-train:latest -t "ghcr.io/coqui-ai/stt-train:${DOCKER_TAG}"
+          docker push "ghcr.io/coqui-ai/stt-train:${DOCKER_TAG}"
+          docker push ghcr.io/coqui-ai/stt-train:latest
   twine-upload-decoder:
     name: "Upload coqui_stt_ctcdecoder packages to PyPI"
     runs-on: ubuntu-20.04