feat: add healthcheck handling to streamable http server MCP-383

[nirinchev]

Proposed changes

This adds two config options - healthCheckPort and healthCheckHost that control a separate express instance we create for k8s/docker health checks.

[Copilot]

Pull request overview

This PR adds health check capabilities to the streamable HTTP server by introducing two new configuration options: healthCheckPort and healthCheckHost. These options enable a separate Express server dedicated to handling Kubernetes and Docker health checks.

Changes:

• Added configuration schema for health check server with validation
• Refactored streamable HTTP transport to support dual server architecture
• Added comprehensive test coverage for health check functionality

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/transports/streamableHttp.ts	Refactored to create separate MCP and health check servers using a shared base class
src/common/config/userConfig.ts	Added healthCheckPort and healthCheckHost configuration schema
src/common/logger.ts	Added log IDs for generic HTTP server lifecycle events
tests/integration/transports/streamableHttp.test.ts	Added health check server tests and updated test setup to use beforeEach
tests/unit/common/config/configOverrides.test.ts	Updated to include new health check fields in override validation
tests/integration/transports/createSessionConfig.test.ts	Updated server address access to use mcpServer property
tests/integration/transports/configOverrides.test.ts	Updated server address access to use mcpServer property
server.json	Added health check configuration to environment variables and CLI arguments

[coveralls]

Pull Request Test Coverage Report for Build 21865226184

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 151 of 166 (90.96%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.5%) to 82.821%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/transports/streamableHttp.ts	131	146	89.73%

Totals
Change from base Build 21864680015:	0.5%
Covered Lines:	7652
Relevant Lines:	9120

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💛 - Coveralls

[himanshusinghs]

Love the change, great readability improvement 🚀

[fmenezes]

LGTM