feat: adopt structlog for structured logging

[Sumitha007]

What this PR does / why we need it

This PR introduces structured logging support to the Kubeflow SDK using structlog.

Changes

• Add a new kubeflow.common.structured_logging module.
• Provide an opt-in configure_logging() API for configuring structured logging.
• Add a get_logger() helper for creating structured loggers.
• Replace logging.getLogger(__name__) with get_logger(__name__) across the SDK modules.
• Preserve existing logging behavior until configure_logging() is explicitly called.

Which issue(s) this PR fixes

Fixes #631

Checklist

• Docs included if any changes are user facing (not applicable)
• Code follows the project style guidelines
• ruff format passed
• ruff check . passed
• Relevant unit tests passed

[google-oss-prow]

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[Sridhar1030]

/assign

[lntutor]

structlog is imported by the new module and by the updated SDK modules, but this PR does not change pyproject.toml or uv.lock to declare it. In a clean repository environment, uv run python -c "import structlog" currently raises ModuleNotFoundError.

That means importing an affected client after this change will fail for downstream users who install the SDK from its declared dependencies. Please add the runtime dependency to pyproject.toml, regenerate uv.lock, and add a small import/configuration test so the package dependency is covered.

[google-oss-prow]

@lntutor: changing LGTM is restricted to collaborators

Details

In response to this:

structlog is imported by the new module and by the updated SDK modules, but this PR does not change pyproject.toml or uv.lock to declare it. In a clean repository environment, uv run python -c "import structlog" currently raises ModuleNotFoundError.

That means importing an affected client after this change will fail for downstream users who install the SDK from its declared dependencies. Please add the runtime dependency to pyproject.toml, regenerate uv.lock, and add a small import/configuration test so the package dependency is covered.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Sumitha007]

Thanks for the review! I've added the structlog dependency, updated uv.lock, and added a structured logging test. Please take another look.

[Sridhar1030]

the file has no logging calls

[Sumitha007]

Thanks! I've removed the unused logger from this file.

[Sridhar1030]

Thanks @Sumitha007
/lgtm
cc @andreyvelich

[Sridhar1030]

hey @Sumitha007 can u resolve the conflicts ?

[google-oss-prow]

New changes are detected. LGTM label has been removed.