Add workflow for release

.github/workflows/release.yaml

@@ -0,0 +1,32 @@
+name: release
+
+on:
+  pull_request:
+    paths:
+      - .github/workflows/release.yaml
+  # release:
+  #   types: [released]
+
+jobs:
+  build:
+    # if: github.event.release.target_commitish == 'master'
+    name: Build and push docker image
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set image tag
+        run: echo "IMAGE_TAG=$(echo ${GITHUB_REF:10})" >> $GITHUB_ENV
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: ./src
+          push: false
+          tags: kanata333/docker-hub-push:latest