feat: Add CloudWatch Synthetics Canary Analysis to Application Signals MCP Server

[rgupta2205]

Add CloudWatch Synthetics Canary Analysis to Application Signals MCP Server

Summary

Changes

Extended the CloudWatch Application Signals MCP Server with comprehensive CloudWatch Synthetics canary analysis capabilities:

• New canary_utils.py: Utility functions for canary failure analysis, IAM role validation, artifact retrieval, and debugging
• Enhanced server.py: Added analyze_canary_failures tool for comprehensive canary failure investigation
• Updated aws_clients.py: Added Synthetics, S3, IAM, Lambda, and STS clients; cleaned up debug logging
• Updated README.md: Added documentation for canary analysis capabilities
• Added comprehensive tests: 21 test scenarios covering real-world canary failure patterns in test_canary_utils.py

User experience

Before: Users could only analyze Application Signals metrics and traces, with no visibility into CloudWatch Synthetics canary failures

After: Users can now:

• Analyze canary failures with comprehensive root cause identification
• Check IAM role configurations and permissions for canaries
• Retrieve and analyze canary artifacts (logs, screenshots, HAR files)
• Get actionable recommendations for resolving canary issues
• Correlate canary failures with Application Signals telemetry data
• Handle edge cases like S3 access errors, connection timeouts, browser target issues, and VPC configuration problems

Key Features Added

• Comprehensive failure analysis with pattern recognition for common canary issues
• IAM role and policy validation with specific permission checks
• Artifact analysis including HAR files, screenshots, and logs
• APM Pulse integration for enhanced diagnostics
• 21 comprehensive test scenarios covering real-world failure patterns
• Robust error handling for AWS API failures and edge cases

Checklist

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested (21/21 tests passing)
• Changes are documented

Is this a breaking change? (Y/N) N

RFC issue number: N/A

Acknowledgment

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.

Reference: https://quip-amazon.com/J1eLAngUZYMB/Cloudwatch-Synthetics-MCP-Server-using-API

Testing

[codecov]

Codecov Report

❌ Patch coverage is 90.35326% with 71 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.49%. Comparing base (a7e8cb9) to head (e689f49).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...s/cloudwatch_appsignals_mcp_server/canary_utils.py	91.71%	13 Missing and 26 partials ⚠️
...awslabs/cloudwatch_appsignals_mcp_server/server.py	87.20%	8 Missing and 24 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1471      +/-   ##
==========================================
+ Coverage   89.48%   89.49%   +0.01%     
==========================================
  Files         729      730       +1     
  Lines       50584    51317     +733     
  Branches     7990     8164     +174     
==========================================
+ Hits        45265    45928     +663     
- Misses       3453     3474      +21     
- Partials     1866     1915      +49     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[yiyuan-he]

Why are there so many new changes? Previously the PR was ~2K lines of code changes and now it is approaching 7K

[rgupta2205]

Why are there so many new changes? Previously the PR was ~2K lines of code changes and now it is approaching 7K

Just adding more unit test as it's (88.99% of diff hit (target 89.48%)) which causing check failure

[yiyuan-he]

Just adding more unit test as it's (88.99% of diff hit (target 89.48%)) which causing check failure

~0.5% additional test coverage results in 5K more lines of code?

[rgupta2205]

Just adding more unit test as it's (88.99% of diff hit (target 89.48%)) which causing check failure

~0.5% additional test coverage results in 5K more lines of code?

Originally it was in 35%

[mxiamxia]

LGTM now. Thx

[yiyuan-he]

LGTM ty