Fix flaky GcsIOIntegrationTest and handle GCS bucket creation race conditions

[shunping]

A flaky test example:
https://github.com/apache/beam/actions/runs/28256309850/job/83720139509

______________ GcsIOIntegrationTest_1.test_create_default_bucket _______________
[gw2] linux -- Python 3.11.15 /runner/_work/beam/beam/build/gradleenv/2050596099/bin/python3

self = <apache_beam.io.gcp.gcsio_integration_test.GcsIOIntegrationTest_1 testMethod=test_create_default_bucket>
mock_default_gcs_bucket_name = <MagicMock name='default_gcs_bucket_name' id='134725042979024'>

...
    
>     bucket = gcsio.get_or_create_default_gcs_bucket(google_cloud_options)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

apache_beam/io/gcp/gcsio_integration_test.py:237: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
apache_beam/io/gcp/gcsio.py:146: in get_or_create_default_gcs_bucket
    return gcs.create_bucket(bucket_name, project, location=region)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
apache_beam/io/gcp/gcsio.py:245: in create_bucket
    bucket = self.client.create_bucket(
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/cloud/storage/client.py:1211: in create_bucket
    api_response = self._post_resource(
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/cloud/storage/client.py:790: in _post_resource
    return self._connection.api_request(
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/cloud/storage/_http.py:123: in api_request
    return call()
           ^^^^^^
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/api_core/retry/retry_unary.py:294: in retry_wrapped_func
    return retry_target(
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/api_core/retry/retry_unary.py:156: in retry_target
    next_sleep = _retry_error_helper(
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/api_core/retry/retry_base.py:216: in _retry_error_helper
    raise final_exc from source_exc
../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/api_core/retry/retry_unary.py:147: in retry_target
            path=path,
            query_params=query_params,
            api_base_url=api_base_url,
            api_version=api_version,
        )
    
        # Making the executive decision that any dictionary
        # data will be sent properly as JSON.
        if data and isinstance(data, dict):
            data = json.dumps(data)
            content_type = "application/json"
    
        response = self._make_request(
            method=method,
            url=url,
            data=data,
            content_type=content_type,
            headers=headers,
            target_object=_target_object,
            timeout=timeout,
            extra_api_info=extra_api_info,
        )
    
        if not 200 <= response.status_code < 300:
>           raise exceptions.from_http_response(response)
E           google.api_core.exceptions.Conflict: 409 POST https://storage.googleapis.com/storage/v1/b?project=apache-beam-testing&prettyPrint=false: Your previous request to create the named bucket succeeded and you already own it.

../../build/gradleenv/2050596099/lib/python3.11/site-packages/google/cloud/_http/__init__.py:494: Conflict

In this PR, we made the following changes:

• Modify get_or_create_default_gcs_bucket in gcsio.py to catch Conflict (409) exceptions, resolving to the existing bucket on concurrent creation requests.
• Add unit tests for default bucket creation conflict handling in gcsio_test.py.
• Modify test_create_default_bucket in gcsio_integration_test.py to generate unique bucket names with a UUID prefix and test parameters to eliminate parallel test thread collisions.

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses flakiness in GcsIOIntegrationTest caused by race conditions during GCS bucket creation. By implementing robust conflict handling for 409 errors and improving the uniqueness of test bucket naming, the changes ensure that concurrent test executions do not interfere with each other, leading to more reliable CI/CD pipelines.

Highlights

• Conflict Handling: Updated get_or_create_default_gcs_bucket in gcsio.py to catch 409 Conflict exceptions, allowing the system to gracefully handle existing buckets during concurrent creation attempts.
• Test Stability: Enhanced GcsIOIntegrationTest by incorporating UUIDs and additional test parameters into bucket names to prevent race conditions and collisions in parallel CI environments.
• Unit Testing: Added comprehensive unit tests in gcsio_test.py to verify the new conflict resolution logic and ensure correct behavior when bucket creation fails.

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[gemini-code-assist]

Code Review

This pull request updates get_or_create_default_gcs_bucket in gcsio.py to handle Conflict exceptions during bucket creation by fetching and validating the existing bucket. It also updates integration tests to use more unique bucket names to prevent collisions, and adds corresponding unit tests. Feedback highlights that the new bucket naming scheme in integration tests could exceed the 63-character GCS limit in regions with long names, suggesting shorter identifiers. Additionally, a redundant inner try-except block in gcsio.py was identified for simplification.

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[github-actions]

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