Add logging with loguru

discord_rss_bot/logger.py

@@ -0,0 +1,89 @@
+"""Configure handlers and formats for application loggers."""
+import logging
+import sys
+from pprint import pformat
+
+# if you dont like imports of private modules
+# you can move it to typing.py module
+from loguru import logger
+from loguru._defaults import LOGURU_FORMAT
+
+
+class InterceptHandler(logging.Handler):
+    """
+    Default handler from examples in loguru documentaion.
+    See https://loguru.readthedocs.io/en/stable/overview.html#entirely-compatible-with-standard-logging
+    """
+
+    def emit(self, record: logging.LogRecord) -> None:
+        # Get corresponding Loguru level if it exists
+        try:
+            level = logger.level(record.levelname).name
+        except ValueError:
+            level = record.levelno
+
+        # Find caller from where originated the logged message
+        frame, depth = logging.currentframe(), 2
+        while frame.f_code.co_filename == logging.__file__:  # type: ignore
+            frame = frame.f_back  # type: ignore
+            depth += 1
+
+        logger.opt(depth=depth, exception=record.exc_info).log(level, record.getMessage())
+
+
+def format_record(record: dict) -> str:
+    """
+    Custom format for loguru loggers.
+    Uses pformat for log any data like request/response body during debug.
+    Works with logging if loguru handler it.
+
+    Example:
+    >>> payload = [{"users":[{"name": "Nick", "age": 87, "is_active": True}, {"name": "Alex", "age": 27, "is_active": True}], "count": 2}] # noqa: E501
+    >>> logger.bind(payload=).debug("users payload")
+    >>> [   {   'count': 2,
+    >>>         'users': [   {'age': 87, 'is_active': True, 'name': 'Nick'},
+    >>>                      {'age': 27, 'is_active': True, 'name': 'Alex'}]}]
+    """
+
+    format_string = LOGURU_FORMAT
+    if record["extra"].get("payload") is not None:
+        record["extra"]["payload"] = pformat(record["extra"]["payload"], indent=4, compact=True, width=120)
+        format_string += "\n<level>{extra[payload]}</level>"  # type: ignore
+
+    format_string += "{exception}\n"  # type: ignore
+    return format_string
+
+
+def init_logging() -> None:
+    """
+    Replaces logging handlers with a handler for using the custom handler.
+
+    WARNING!
+    if you call the init_logging in startup event function,
+    then the first logs before the application start will be in the old format
+
+    >>> app.add_event_handler("startup", init_logging)
+    stdout:
+    INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
+    INFO:     Started reloader process [11528] using statreload
+    INFO:     Started server process [6036]
+    INFO:     Waiting for application startup.
+    2020-07-25 02:19:21.357 | INFO     | uvicorn.lifespan.on:startup:34 - Application startup complete.
+
+    """
+
+    # disable handlers for specific uvicorn loggers
+    # to redirect their output to the default uvicorn logger
+    # works with uvicorn==0.11.6
+    loggers = (logging.getLogger(name) for name in logging.root.manager.loggerDict if name.startswith("uvicorn."))
+    for uvicorn_logger in loggers:
+        uvicorn_logger.handlers = []
+
+    # change handler for default uvicorn logger
+    intercept_handler: InterceptHandler = InterceptHandler()
+    logging.getLogger("uvicorn").handlers = [intercept_handler]
+    logging.getLogger("reader").handlers = [intercept_handler]
+    logging.getLogger("apscheduler.executors.default").handlers = [intercept_handler]
+
+    # set logs output, level and format
+    logger.configure(handlers=[{"sink": sys.stdout, "level": logging.DEBUG, "format": format_record}])