Fix Cloud Run deferrable trigger handling of transient grpc errors

[akshetpandey]

related: #66293

Problem

CloudRunJobFinishedTrigger.run() polls the long-running operation via
CloudRunAsyncHook.get_operation in its loop. When that gRPC call fails
with a transient error — typical of a regional Cloud Run API blip while
the underlying job is still progressing fine — the exception
propagates out of the trigger:

1. The triggerer logs the failure and tears down the trigger.
2. The deferred task fails with TaskDeferralError.
3. The worker's task-level retry re-runs the operator from scratch,
   which submits a brand new Cloud Run execution rather than
   waiting on the in-flight one. So a 1-second transient API blip turns
   into a duplicate (and billed) job run.

This mirrors the same class of bug fixed for Dataflow in #66293.

How to fix

Catch the full set of retryable gRPC errors inside the Cloud Run
get-operation polling loop, log a warning, sleep
polling_period_seconds, and continue polling. The retryable tuple is:

• ServiceUnavailable (503 / UNAVAILABLE)
• InternalServerError (500 / INTERNAL)
• DeadlineExceeded (504 / DEADLINE_EXCEEDED)
• GatewayTimeout
• ResourceExhausted (429 / RESOURCE_EXHAUSTED)
• Aborted

Anything outside that tuple (PermissionDenied, NotFound, auth
failures, unexpected RuntimeErrors) still propagates, so Airflow's
task-level retry remains the safety net for genuinely terminal
failures.

Tests

uv run --project providers/google pytest providers/google/tests/unit/google/cloud/triggers/test_cloud_run.py -xvs

Two parametrized tests cover the new behavior:

• test_trigger_continues_polling_after_retryable_grpc_error — runs
  once per entry in the retryable tuple. The first get_operation
  raises the parametrized exception; the second returns a successfully
  completed operation. The trigger must yield the SUCCESS
TriggerEvent and asyncio.sleep must be awaited exactly once with
  polling_period_seconds.
• test_trigger_propagates_unexpected_polling_exception —
  parametrized over PermissionDenied and a bare RuntimeError. Both
  must still propagate out of run(), locking in that only the
  retryable tuple is swallowed.

All pre-existing tests in test_cloud_run.py continue to pass.

---

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• Yes (please specify the tool below)
  Generated-by: Claude Opus 4.7 following the guidelines

[boring-cyborg]

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[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds resilience to the Cloud Run job-finished trigger by retrying transient Cloud Run API 503s during polling, preventing deferred tasks from failing and re-submitting jobs unnecessarily.

Changes:

• Retry get_operation polling when google.api_core.exceptions.ServiceUnavailable occurs.
• Add unit tests to verify retry-on-503 behavior and propagation of non-retryable exceptions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
providers/google/src/airflow/providers/google/cloud/triggers/cloud_run.py	Catch and retry ServiceUnavailable during operation polling with a logged warning and sleep.
providers/google/tests/unit/google/cloud/triggers/test_cloud_run.py	Add tests covering retryable 503 behavior and non-retryable exception propagation.

[akshetpandey]

@shahar1 Updated the PR to address your comments

[shahar1]

LGTM!

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.