[ENH]: Empty OTEL endpoint won't cause panic + OTEL standard exporter env var support

[tazarov]

Closes #4609

Description of changes

Summarize the changes made by this PR.

• Improvements & Bug fixes
  • If OTEL endpoint is empty string then OTEL layer becomes Identity (noop)
  • Support for OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_ENDPOINT to that conform to OTEL SDK config - https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/

Test plan

How are these changes tested?

• Tests pass locally with pytest for python, yarn test for js, cargo test for rust

Documentation Changes

TBD

[github-actions]

Reviewer Checklist

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Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)

[tazarov]

• [ENH]: Empty OTEL endpoint won't cause panic + OTEL standard exporter env var support #4622 👈 (View in Graphite)
• main

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[propel-code-bot]

Handle Empty OTEL Endpoint Gracefully & Add OTEL Exporter Env Var Support

This PR improves the OpenTelemetry (OTEL) initialization logic in the Rust tracing module by ensuring that an empty OTEL endpoint no longer causes a panic-instead, it falls back to a no-operation (Identity) layer. Additionally, it enhances environment variable support to align with OTEL standards by checking OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_ENDPOINT variables per upstream SDK configuration guidelines.

Key Changes:
• init_otel_layer checks OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_ENDPOINT environment variables for endpoint value, falling back to parameter if unset.
• If the resolved OTEL endpoint is empty, the function returns an Identity (noop) tracing layer instead of causing a panic.
• Metric exporter now also uses OTEL_EXPORTER_OTLP_METRICS_ENDPOINT, falling back to the final endpoint if not set.
• Function signatures updated to use &str, improving ergonomics and reducing unnecessary String cloning.

Affected Areas:
• rust/tracing/src/init_tracer.rs

This summary was automatically generated by @propel-code-bot