chore: route uvicorn logs to structlog; disable default access logs

app/logging_config.py

@@ -9,6 +9,7 @@ included automatically in log records.
 from __future__ import annotations
 
 import logging
+import logging.config
 from typing import Any, Dict
 
 import structlog
@@ -29,29 +30,93 @@ def _add_required_defaults(_: Any, __: str, event_dict: Dict[str, Any]) -> Dict[
     return event_dict
 
 
+def _build_foreign_pre_chain() -> list:
+    """Common processor chain used for stdlib log bridging."""
+    return [
+        structlog.contextvars.merge_contextvars,
+        structlog.stdlib.add_log_level,
+        _add_required_defaults,
+        structlog.processors.TimeStamper(fmt="iso", key="timestamp"),
+        structlog.processors.dict_tracebacks,
+    ]
+
+
+def _ensure_stdlib_processor_logging(log_level: int) -> None:
+    """Route stdlib (and uvicorn) loggers through structlog's ProcessorFormatter.
+
+    This ensures uvicorn error logs and any stdlib logs are emitted as JSON,
+    matching the structlog output used by the application code.
+    """
+    formatter = structlog.stdlib.ProcessorFormatter(
+        processor=structlog.processors.JSONRenderer(),
+        foreign_pre_chain=_build_foreign_pre_chain(),
+    )
+
+    handler = logging.StreamHandler()
+    handler.setFormatter(formatter)
+
+    # Root logger
+    root_logger = logging.getLogger()
+    root_logger.handlers = [handler]
+    root_logger.setLevel(log_level)
+
+    # Uvicorn loggers (error/access/parent)
+    for name in ("uvicorn", "uvicorn.error", "uvicorn.access"):
+        uv_logger = logging.getLogger(name)
+        uv_logger.handlers = [handler]
+        uv_logger.propagate = False
+        uv_logger.setLevel(log_level)
+
+
+def build_uvicorn_structlog_formatter() -> logging.Formatter:
+    """
+    Factory used by logging.config.dictConfig to create a ProcessorFormatter
+    that renders JSON and merges contextvars. This is referenced by
+    app/uvicorn_log_config.json.
+    """
+    return structlog.stdlib.ProcessorFormatter(
+        processor=structlog.processors.JSONRenderer(),
+        foreign_pre_chain=_build_foreign_pre_chain(),
+    )
+
+
 def setup_logging(log_level: int = logging.INFO) -> None:
     """
-    Configure structlog for JSON logging with contextvars support.
+    Configure structlog for JSON logging with contextvars support and bridge
+    stdlib/uvicorn loggers to JSON output.
 
     Args:
         log_level: Minimum log level for application logs.
     """
-    # Configure stdlib logging basic config for third-party libs (uvicorn, etc.)
+    # Do not clobber handlers if already configured by a log-config (e.g., uvicorn --log-config)
+    # basicConfig is a no-op if handlers exist.
     logging.basicConfig(level=log_level)
 
     structlog.configure(
         processors=[
+            structlog.stdlib.filter_by_level,
             structlog.contextvars.merge_contextvars,
             structlog.stdlib.add_log_level,
             _add_required_defaults,
             structlog.processors.TimeStamper(fmt="iso", key="timestamp"),
             structlog.processors.dict_tracebacks,
-            structlog.processors.JSONRenderer(),
+            # Defer rendering to logging's ProcessorFormatter to avoid double JSON
+            structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
         ],
         context_class=dict,
         logger_factory=structlog.stdlib.LoggerFactory(),
-        wrapper_class=structlog.make_filtering_bound_logger(log_level),
+        wrapper_class=structlog.stdlib.BoundLogger,
         cache_logger_on_first_use=True,
     )
 
+    # If uvicorn/root handlers are not already using ProcessorFormatter, ensure they do.
+    def _has_processor_formatter(logger: logging.Logger) -> bool:
+        for h in logger.handlers:
+            if isinstance(getattr(h, "formatter", None), structlog.stdlib.ProcessorFormatter):
+                return True
+        return False
+
+    if not (_has_processor_formatter(logging.getLogger()) or _has_processor_formatter(logging.getLogger("uvicorn"))):
+        _ensure_stdlib_processor_logging(log_level)
+