ci: breakout docker build for merge only

.github/workflows/ci.yml

@@ -41,24 +41,6 @@ jobs:
       run: cd build && cmake --build . --config Release
     - name: Build RPC (Debug)
       run: cd build && cmake --build . --config Debug
-
-  build-docker:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: docker build
-        run: docker build -f "Dockerfile" --tag vprodemo.azurecr.io/rpc:${{ github.sha }} --tag vprodemo.azurecr.io/rpc:latest .
-      - name: Docker Login
-        uses: docker/login-action@v1.6.0
-        with:
-          registry: vprodemo.azurecr.io
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
-          logout: true
-      - name: Push the Docker image to the registry
-        run: docker push vprodemo.azurecr.io/rpc:${{ github.sha }}
-      - name: Push the Docker image to the registry
-        run: docker push vprodemo.azurecr.io/rpc:latest
         
   build-linux:
     runs-on: ${{ matrix.os }}

.github/workflows/docker-ci.yml

@@ -0,0 +1,29 @@
+#*********************************************************************
+# Copyright (c) Intel Corporation 2020
+# SPDX-License-Identifier: Apache-2.0
+#*********************************************************************/
+
+name: Docker Image CI
+
+on:
+  push:
+      branches: [ master ]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build the Docker image
+        run: docker build -f "Dockerfile" --tag vprodemo.azurecr.io/rpc:${{ github.sha }} --tag vprodemo.azurecr.io/rpc:latest .
+      - name: Docker Login
+        uses: docker/login-action@v1.6.0
+        with:
+          registry: vprodemo.azurecr.io
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+          logout: true
+      - name: Push the Docker image to the registry
+        run: docker push vprodemo.azurecr.io/rpc:${{ github.sha }}
+      - name: Push the Docker image to the registry
+        run: docker push vprodemo.azurecr.io/rpc:latest