014 add json logging

app/runtime/__init__.py

@@ -0,0 +1 @@
+"""Runtime support modules."""

app/runtime/logging.py

@@ -0,0 +1,78 @@
+"""Centralized runtime logging bootstrap."""
+
+import logging
+import sys
+from collections.abc import Iterable
+from typing import TextIO
+
+import structlog
+
+
+_UVICORN_LOGGER_NAMES = ("uvicorn", "uvicorn.error", "uvicorn.access")
+
+
+def configure_logging(
+    *,
+    log_level: int = logging.INFO,
+    stream: TextIO | None = None,
+) -> None:
+    resolved_stream = sys.stdout if stream is None else stream
+    formatter = structlog.stdlib.ProcessorFormatter(
+        foreign_pre_chain=list(_shared_processors()),
+        processors=[
+            structlog.stdlib.ProcessorFormatter.remove_processors_meta,
+            structlog.processors.JSONRenderer(sort_keys=True),
+        ],
+    )
+    handler = logging.StreamHandler(resolved_stream)
+    handler.setLevel(log_level)
+    handler.setFormatter(formatter)
+
+    structlog.reset_defaults()
+    structlog.configure(
+        processors=[
+            *_shared_processors(),
+            structlog.stdlib.PositionalArgumentsFormatter(),
+            structlog.processors.StackInfoRenderer(),
+            structlog.processors.format_exc_info,
+            structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
+        ],
+        logger_factory=structlog.stdlib.LoggerFactory(),
+        wrapper_class=structlog.stdlib.BoundLogger,
+        cache_logger_on_first_use=True,
+    )
+
+    _configure_logger(logging.getLogger(), handler=handler, log_level=log_level)
+    for logger_name in _UVICORN_LOGGER_NAMES:
+        _configure_logger(
+            logging.getLogger(logger_name),
+            handler=handler,
+            log_level=log_level,
+            propagate=False,
+        )
+
+
+def _shared_processors() -> tuple[structlog.types.Processor, ...]:
+    return (
+        structlog.stdlib.add_logger_name,
+        structlog.stdlib.add_log_level,
+        structlog.processors.TimeStamper(fmt="iso", utc=True),
+    )
+
+
+def _configure_logger(
+    logger: logging.Logger,
+    *,
+    handler: logging.Handler,
+    log_level: int,
+    propagate: bool = True,
+) -> None:
+    _clear_handlers(logger.handlers)
+    logger.setLevel(log_level)
+    logger.handlers = [handler]
+    logger.propagate = propagate
+
+
+def _clear_handlers(handlers: Iterable[logging.Handler]) -> None:
+    for existing_handler in list(handlers):
+        existing_handler.close()