app/core/logging.py

"""
Structured logging configuration.
"""

import logging
import sys
import json
from datetime import datetime, timezone


class JSONFormatter(logging.Formatter):
    """Emit log records as single-line JSON objects."""

    def format(self, record: logging.LogRecord) -> str:
        log_entry = {
            "timestamp": datetime.now(timezone.utc).isoformat(),
            "level": record.levelname,
            "logger": record.name,
            "message": record.getMessage(),
        }
        if record.exc_info and record.exc_info[0] is not None:
            log_entry["exception"] = self.formatException(record.exc_info)
        return json.dumps(log_entry)


def setup_logging(level: int = logging.INFO) -> None:
    """Configure root logger with structured JSON output to stderr."""
    handler = logging.StreamHandler(sys.stderr)
    handler.setFormatter(JSONFormatter())

    root = logging.getLogger()
    root.setLevel(level)
    root.addHandler(handler)

    # Quieten noisy third-party loggers
    logging.getLogger("uvicorn.access").setLevel(logging.WARNING)
    logging.getLogger("motor").setLevel(logging.WARNING)


def get_logger(name: str) -> logging.Logger:
    """Return a named logger."""
    return logging.getLogger(name)