changed Github actions to build only for main branch

Author: mmahipal

.github/workflows/github-actions.yml

@@ -1,7 +1,8 @@
 name: Docker
 
 on:
-  push
+  push:
+    branches: [ main ]
 
 env:
   # Use docker.io for Docker Hub if empty
@@ -26,7 +27,6 @@ jobs:
       # Login against a Docker registry except on PR
       # https://github.com/docker/login-action
       - name: Log into registry ${{ env.REGISTRY }}
-        if: github.event_name != 'pull_request'
         uses: docker/login-action@28218f9b04b4f3f62068d7b6ce6ca5b26e35336c
         with:
           registry: ${{ env.REGISTRY }}
@@ -35,12 +35,10 @@ jobs:
 
       # Build and push Operator image (don't push on PR)
       - name: Build and push Docker image
-        if: github.event_name != 'pull_request'
         run:  |
           make generate
           make manifests
-          IMAGE=${{ env.IMAGE_NAME }}
-          IMAGE=${IMAGE,,}
+          IMAGE=${${{ env.IMAGE_NAME }},,}
           make docker-build IMG="${{ env.REGISTRY }}/${IMAGE}:${GITHUB_REF##*/}"
           docker push "${{ env.REGISTRY }}/${IMAGE}:${GITHUB_REF##*/}"
           docker rmi "${{ env.REGISTRY }}/${IMAGE}:${GITHUB_REF##*/}" && docker system prune -f