docs: document env.VAR_NAME support for collector_url, metrics_endpoint, and Prometheus Push Gateway fields

[BearTS]

Summary

Documents environment variable substitution support for collector_url, metrics_endpoint, and Prometheus Push Gateway fields (push_gateway_url, username, password). Previously, only header values were documented as supporting env.VAR_NAME — this update clarifies that endpoint URLs and credentials can also reference environment variables, keeping sensitive values out of stored configuration.

Changes

• Updated collector_url and metrics_endpoint field types to string | EnvVar and noted env.VAR_NAME support in their descriptions
• Updated push_gateway_url, username, and password field types to string | EnvVar with the same notation
• Expanded the "Environment Variable Substitution" section in the OTel docs to include collector_url and metrics_endpoint in the example and explanation
• Clarified that stored configuration retains the env.VAR_NAME string and that resolved values are never persisted or returned in API responses
• Added a new "With Environment Variables" example block to the Prometheus docs showing push_gateway_url, username, and password using env.VAR_NAME

Type of change

• Bug fix
• Feature
• Refactor
• Documentation
• Chore/CI

Affected areas

• Core (Go)
• Transports (HTTP)
• Providers/Integrations
• Plugins
• UI (React)
• Docs

How to test

Review the updated docs pages for the OTel and Prometheus plugins and verify:

• Field type columns reflect string | EnvVar where applicable
• Example JSON snippets include env.VAR_NAME usage for endpoint URLs and credentials
• The security behavior description (no persistence of resolved values, redaction in API responses) is accurate against the implementation

Breaking changes

• Yes
• No

Security considerations

The documentation now explicitly states that resolved environment variable values are never persisted to the database or config file, and that API responses return EnvVar objects with sensitive resolved values redacted. This is a documentation clarification of existing security behavior.

Checklist

• I read docs/contributing/README.md and followed the guidelines
• I added/updated tests where appropriate
• I updated documentation where needed
• I verified builds succeed (Go and UI)
• I verified the CI pipeline passes locally if applicable

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

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📥 Commits

Reviewing files that changed from the base of the PR and between 74831c9 and a1f3163.

📒 Files selected for processing (2)

• docs/features/observability/otel.mdx
• docs/features/observability/prometheus.mdx

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch 05-26-docs_update_otel_and_prometheus_docs

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[BearTS]

• docs: document env.VAR_NAME support for collector_url, metrics_endpoint, and Prometheus Push Gateway fields #3753 👈 (View in Graphite)
• dev

This stack of pull requests is managed by Graphite. Learn more about stacking.

[greptile-apps]

Confidence Score: 5/5

Documentation-only changes with no code modifications; safe to merge.

Both files contain only prose, table, and JSON example updates. The new content accurately describes the env var substitution feature and the JSON snippets are well-formed. No logic, config defaults, or runtime behaviour is altered.

No files require special attention.

Important Files Changed

Filename	Overview
docs/features/observability/otel.mdx	Documents env var substitution support for collector_url and metrics_endpoint fields; updates type annotations and adds example JSON snippets
docs/features/observability/prometheus.mdx	Documents env var substitution for push_gateway_url, username, and password; adds a new "With Environment Variables" config example inside the Config File tab

_{Reviews (1): Last reviewed commit: "docs: update otel and prometheus docs" | Re-trigger Greptile}

[akshaydeo]

Merge activity

• May 26, 8:55 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• May 26, 8:56 AM UTC: @akshaydeo merged this pull request with Graphite.