1. Add explicit permissions (least privilege):
- contents: read
- checks: write (for test reports)
- pull-requests: write (for PR comments)
2. Extract duplicate build steps into shared 'build-deps' job:
- Eliminates duplication between spark-tests and spark-example
- Build artifacts are uploaded and reused by dependent jobs
- Reduces CI time and ensures consistency
3. Fix spark-example service startup verification:
- Match robust approach from spark-tests job
- Add explicit timeout and failure handling
- Verify all services (master, volume, filer)
- Include diagnostic logging on failure
- Prevents silent failures and obscure errors
These changes improve maintainability, security, and reliability
of the Spark integration test workflow.