feat(agentless): only push agent containers on merges to main

Author: mskalka

.github/workflows/agentless-container.yaml

@@ -2,6 +2,12 @@ name: Build and push agentless container image
 
 # Configures this workflow to run every time a tag is created
 on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - containers/agentless/**
+      - .github/workflows/agentless-container.yaml
   push:
     branches: 
       - main
@@ -57,7 +63,10 @@ jobs:
           done
           TAGS=$(echo $TAGS | tr '[:upper:]' '[:lower:]')
 
-          docker buildx build --push --platform linux/amd64,linux/arm64 $TAGS --metadata-file=metadata.json -f ../containers/agentless/Dockerfile ../containers/agentless
+          # GITHUB_BASE_REF is only set when the action source event is a pull request.
+          # in that case don't push.
+          export PUSH=$(if [ -z ${GITHUB_BASE_REF+x} ]; then echo "--push"; else echo ""; fi)
+          docker buildx build $PUSH --platform linux/amd64,linux/arm64 $TAGS --metadata-file=metadata.json -f ../containers/agentless/Dockerfile ../containers/agentless
 
           cat metadata.json
           echo "digest=$(cat metadata.json | jq -r .\"containerimage.digest\")" >> $GITHUB_OUTPUT