Investigation findings:
- JSON logging WORKS correctly in single-process mode
- All test scripts show proper JSON formatting with stacktraces
- Issue likely caused by multi-worker setup where _turn_on_json()
is only called in main process, not worker processes
Test scripts added:
- test_json_logs_reproducer.py: Basic JSON logging with env var
- test_json_logs_late_enable.py: Tests late JSON logs enablement
- test_logging_handlers.py: Analyzes logger handler hierarchy
- test_proxy_json_logs_reproducer.py: Simulates exact proxy startup
- test_json_logs_config.yaml: Minimal proxy config for testing
Documentation:
- JSON_LOGS_REPRODUCTION.md: Comprehensive investigation findings,
reproduction steps, and recommended solutions
Root cause: When using multiple workers (gunicorn/uvicorn), each
worker process has its own logging configuration. The _turn_on_json()
call in main process doesn't propagate to workers.
Recommended fix: Ensure _turn_on_json() is called in each worker
process during initialization, or set JSON_LOGS env var before import.
