code review change

Author: nshyrei

.github/workflows/build-docker-images.yml

@@ -8,32 +8,73 @@ on:
       - 'docker/parent-base/**'
   pull_request:
     branches: [ "master" ]
+    types:
+      - closed
+      - opened
     paths:
       - 'docker/enclave-base/**'
       - 'docker/parent-base/**'
 
 jobs:
-  build-and-publish:
+  build-docker-images:
     runs-on: ubuntu-20.04
+    if: github.event_name == 'pull_request' && github.event.action == 'opened'
     steps:
       - name: Pull main repository
         uses: actions/checkout@v3
         with:
           repository: fortanix/salmiac
 
-      - name: Login to Docker Hub
-        uses: docker/login-action@v1
-        with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
-
       - name: Build docker images
         run: |
           cd docker/enclave-base
           docker build -t fortanix/enclave-base .
+          docker save -o /tmp/enclave-base.tar fortanix/enclave-base
 
           cd ../parent-base
           docker build -t fortanix/parent-base .
+          docker save -o /tmp/parent-base.tar fortanix/parent-base
+
+      - name: Upload enclave-base artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: enclave-base
+          path: /tmp/enclave-base.tar
+
+      - name: Upload parent-base artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: parent-base
+          path: /tmp/parent-base.tar
+
+  push-docker-images:
+    runs-on: ubuntu-20.04
+    needs: build-docker-images
+    if: github.event_name == 'pull_request' && github.event.action == 'closed' && github.event.pull_request.merged == true
+    steps:
+      - name: Download enclave-base artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: enclave-base
+          path: /tmp/enclave-base
+      - name: Load enclave-base image
+        run: |
+          docker load --input /tmp/enclave-base/enclave-base.tar
+
+      - name: Download parent-base artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: parent-base
+          path: /tmp/parent-base
+      - name: Load parent-base image
+        run: |
+          docker load --input /tmp/parent-base/parent-base.tar
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Push docker images
         run: |