add dockerhub workflow

Author: manuwei

.github/workflows/dockerhub.yml

@@ -0,0 +1,42 @@
+name: Push docker images to Dockerhub
+
+on:
+  push:
+    branches: master
+    tags:
+      - "v*.*.*"
+
+jobs:
+  multi:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set output
+        id: vars
+        run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+      - name: Build and push latest Pattern Atlas UI
+        if: ${{ steps.vars.outputs.tag == 'master' }}
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: patternatlas/pattern-atlas-db:latest
+
+      - name: Build and push version of Pattern Atlas UI
+        if: ${{ steps.vars.outputs.tag != 'master' }}
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: patternatlas/pattern-atlas-db:${{ steps.vars.outputs.tag }}