Reduce the Images Size

1. Update script to reduce the size of images by splitting nn and non-nn.
2. Add github action workflow to build and push images on master changed or tagged.

Signed-off-by: jiahaoc <[email protected]>

.github/workflows/docker_push.yaml

@@ -0,0 +1,41 @@
+name: Docker
+
+on:
+  push:
+    # Publish `master` as Docker `latest` image.
+    branches:
+      - master
+
+    # Publish `v1.2.3` tags as releases.
+    tags:
+      - v*
+
+jobs:
+  # no test is required
+  push:
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push'
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Prepare the TAG
+        id: prepare-the-tag
+        run: |
+          # strip git ref prefix from version
+          TAG=""
+          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
+          if [ $VERSION = "master" ]; then
+            TAG=latest
+          fi
+
+          echo "::set-output name=tag::$TAG"
+
+      - name: Build image
+        run: TAG=${{steps.prepare-the-tag.outputs.tag}} bash docker-build/build_cluster_docker.sh all
+
+      - name: Log into DockerHub
+        run: docker login -u ${{ secrets.DOCKERHUB_USERNAME }} -p ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Push image
+        run: TAG=${{steps.prepare-the-tag.outputs.tag}} bash docker-build/build_cluster_docker.sh push