Update Correlation Context Documentation

[Copilot]

Summary

This PR adds support for correlating frontend and backend applications by adding support for sessionId and ai-session-id headers in the correlation context manager. This enables better end-to-end tracing in Application Insights between frontend and backend components.

Changes

• Enhanced correlationContextManager.ts to detect and process sessionId and ai-session-id headers from incoming requests
• Modified generateContextObject method to store the session ID in the correlation context's custom properties
• Added comprehensive tests to verify the new functionality
• Added documentation in the README explaining the supported headers for frontend-backend correlation

Usage

When using Application Insights in both frontend (with @microsoft/applicationinsights-web) and backend (with this package), the correlation will now work automatically if the frontend includes any of these headers:

• traceparent: W3C trace context header (primary header for distributed tracing)
• tracestate: W3C trace state header (optional)
• request-id: Legacy Application Insights header (fallback)
• sessionId or ai-session-id: Session ID for correlation (new support added)

The backend will automatically pick up these headers and establish the proper correlation context, allowing you to see related telemetry in the Azure Portal.

Fixes #1333.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• global.livediagnostics.monitor.azure.com
  • Triggering command: node /home/REDACTED/work/ApplicationInsights-node.js/ApplicationInsights-node.js/node_modules/.bin/mocha ./out/test/unitTests --recursive (dns block)
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• westus-0.in.applicationinsights.azure.com
  • Triggering command: node /home/REDACTED/work/ApplicationInsights-node.js/ApplicationInsights-node.js/node_modules/.bin/mocha ./out/test/unitTests --recursive (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

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[JacksonWeber]

Please address the documentation question at the bottom of the thread on this issue.

[JacksonWeber]

Remove sessionId from the readme and do not change any code files, JUST documentation.

[Copilot]

Please address the documentation question at the bottom of the thread on this issue.

I've enhanced the "Frontend to Backend Correlation" documentation in the README.md with detailed examples explaining how correlation works between frontend and backend applications. The documentation now includes:

1. Clear explanation of supported headers
2. Frontend setup with code sample
3. Description of how headers are automatically processed
4. Clarification that no manual code is required for correlation

These changes are in commit cbb5892.

[Copilot]

Remove sessionId from the readme and do not change any code files, JUST documentation.

I've removed all references to sessionId from the README.md while maintaining the ai-session-id header documentation. No code files were modified as requested. Changes are in commit 8e4b74b.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• cdn.fwupd.org
  • Triggering command: /usr/bin/fwupdmgr refresh (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• global.livediagnostics.monitor.azure.com
  • Triggering command: node /home/REDACTED/work/ApplicationInsights-node.js/ApplicationInsights-node.js/node_modules/.bin/mocha ./out/test/unitTests --recursive (dns block)
• westus-0.in.applicationinsights.azure.com
  • Triggering command: node /home/REDACTED/work/ApplicationInsights-node.js/ApplicationInsights-node.js/node_modules/.bin/mocha ./out/test/unitTests --recursive (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list