Cache images slightly differently (#165)

.github/actions/run-interop-ping-test/action.yml

@@ -34,6 +34,12 @@ runs:
         echo "AWS_REGION=${{ inputs.aws-region }}" >> $GITHUB_ENV
       shell: bash
 
+    - name: Configure AWS credentials for S3 build cache
+      if: inputs.s3-access-key-id != '' && inputs.s3-secret-access-key != ''
+      run: |
+        echo "PUSH_CACHE=true" >> $GITHUB_ENV
+      shell: bash
+
     - name: Configure AWS credentials for S3 build cache
       if: inputs.s3-access-key-id != '' && inputs.s3-secret-access-key != ''
       uses: aws-actions/configure-aws-credentials@v1
@@ -63,9 +69,15 @@ runs:
       run: npm ci
       shell: bash
 
-    - name: Build images
+    - name: Load cache and build
       working-directory: ${{ steps.find-workdir.outputs.WORK_DIR }}
-      run: make
+      run: npm run cache -- load
+      shell: bash
+
+    - name: Push the image cache
+      if: env.PUSH_CACHE == 'true'
+      working-directory: ${{ steps.find-workdir.outputs.WORK_DIR }}
+      run: npm run cache -- push
       shell: bash
 
     - name: Run the test