Add build and push step to GitHub Actions

.github/workflows/lint-test.yaml → .github/workflows/lint-test-build.yaml

@@ -115,3 +115,39 @@ jobs:
       - name: Tear down docker-compose containers
         run: docker-compose stop
         if: ${{ always() }}
+
+  build-and-push:
+    needs: lint-test
+    if: github.event_name != 'pull_request_target' && github.ref == 'refs/heads/master'
+    runs-on: ubuntu-latest
+
+    steps:
+      # Create a commit SHA-based tag for the container repositories
+      - name: Create SHA Container Tag
+        id: sha_tag
+        run: |
+          tag=$(cut -c 1-7 <<< $GITHUB_SHA)
+          echo "::set-output name=tag::$tag"
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to Github Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GHCR_TOKEN  }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          cache-from: type=registry,ref=ghcr.io/python-discord/site:latest
+          tags: |
+            ghcr.io/python-discord/site:latest
+            ghcr.io/python-discord/site:${{ steps.sha_tag.outputs.tag }}