Update the release workflow

Use the actions and GITHUB_TOKEN as described in https://docs.github.com/en/actions/language-and-framework-guides/publishing-docker-images#publishing-images-to-github-packages.

Signed-off-by: Jan Schlicht <[email protected]>

.github/workflows/release-workflow.yml

@@ -1,8 +1,7 @@
 name: Release Workflow
 on:
-  push:
-    tags:
-      - 'v*.*.*'
+  release:
+    types: [published]
 
 jobs:
   build:
@@ -12,18 +11,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Login to Github Package Registry
-        env:
-          DOCKER_USERNAME: ${{ secrets.DOCKER_GITHUB_USERNAME }}
-          DOCKER_PASSWORD: ${{ secrets.DOCKER_GITHUB_KEY }}
-          DOCKER_REGISTRY_URL: "docker.pkg.github.com"
-        run: docker login -u ${DOCKER_USERNAME} -p ${DOCKER_PASSWORD} ${DOCKER_REGISTRY_URL}
-
-      - name: Set version env
-        run: echo "::set-env name=GIT_TAG::${GITHUB_REF#refs/*/}"
-
-      - name: Build Docker container
-        run: docker build -f build/Dockerfile -t docker.pkg.github.com/kudobuilder/kitt/kitt:$GIT_TAG .
-
-      - name: Push Docker container
-        run: docker push docker.pkg.github.com/kudobuilder/kitt/kitt:$GIT_TAG
+      - name: Push to Github Packages
+        uses: docker/build-push-action@v1
+        with:
+          dockerfile: build/Dockerfile
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+          registry: docker.pkg.github.com
+          repository: kudobuilder/kitt/kitt
+          tag_with_ref: true