Avoid basicConfig on import; add setup_fancy_logger for dynamic log l…

…evel (#307)

pgqueuer/cli.py

@@ -12,7 +12,7 @@
 from typer import Context
 from typing_extensions import AsyncGenerator
 
-from . import db, factories, helpers, listeners, models, qb, queries, supervisor
+from . import db, factories, helpers, listeners, logconfig, models, qb, queries, supervisor
 
 try:
     from uvloop import run as asyncio_run
@@ -391,10 +391,18 @@ def run(
         "--restart-on-failure",
         help="Restart the manager if it fails.",
     ),
+    log_level: logconfig.LogLevel | None = typer.Option(
+        None,
+        "--log-level",
+        help="Set pgqueuer log level.",
+    ),
 ) -> None:
     """
     Run the job manager, pulling tasks from the queue and handling them with workers.
     """
+    if log_level:
+        logconfig.setup_fancy_logger(log_level)
+
     asyncio_run(
         supervisor.runit(
             factories.load_factory(factory_fn),

pgqueuer/logconfig.py

@@ -1,17 +1,92 @@
 """
 Logging configuration for the pgqueuer application.
-
-This module initializes the logging settings for the application. It sets up a logger
-named 'pgqueuer' and configures its log level based on the 'LOGLEVEL' environment variable.
-If 'LOGLEVEL' is not set, it defaults to 'INFO'.
 """
 
 from __future__ import annotations
 
 import logging
-import os
+import logging.config
+import sys
+from datetime import datetime
+from enum import Enum
 from typing import Final
 
-logging.basicConfig()
+
+class LogLevel(Enum):
+    CRITICAL = "CRITICAL"
+    FATAL = "FATAL"
+    ERROR = "ERROR"
+    WARN = "WARN"
+    WARNING = "WARNING"
+    INFO = "INFO"
+    DEBUG = "DEBUG"
+    NOTSET = "NOTSET"
+
+
+class ISOFormatter(logging.Formatter):
+    """Outputs log timestamps in ISO 8601 format with timezone information."""
+
+    def formatTime(self, record: logging.LogRecord, datefmt: str | None = None) -> str:
+        return datetime.fromtimestamp(record.created).astimezone().isoformat()
+
+
+class MaxLevelFilter(logging.Filter):
+    """Only allows log records up to a specified maximum logging level."""
+
+    def __init__(self, max_level: int):
+        super().__init__()
+        self.max_level = max_level
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        return record.levelno <= self.max_level
+
+
+def setup_fancy_logger(level: LogLevel) -> None:
+    """
+    Update the 'pgqueuer' logger's level dynamically.
+    """
+
+    logging.config.dictConfig(
+        {
+            "version": 1,
+            "disable_existing_loggers": False,
+            "formatters": {
+                "default": {
+                    "()": ISOFormatter,
+                    "format": "%(asctime)s [%(name)s] %(levelname)s: %(message)s",
+                },
+            },
+            "filters": {
+                "max_info": {
+                    "()": MaxLevelFilter,
+                    "max_level": logging.INFO,
+                },
+            },
+            "handlers": {
+                "stdout": {
+                    "class": "logging.StreamHandler",
+                    "level": "DEBUG",
+                    "formatter": "default",
+                    "stream": sys.stdout,
+                    "filters": ["max_info"],
+                },
+                "stderr": {
+                    "class": "logging.StreamHandler",
+                    "level": "WARNING",
+                    "formatter": "default",
+                    "stream": sys.stderr,
+                },
+            },
+            "loggers": {
+                "pgqueuer": {
+                    "handlers": ["stdout", "stderr"],
+                    "level": level.name,
+                }
+            },
+        }
+    )
+
+
+# Create the 'pgqueuer' logger and attach a NullHandler by default.
 logger: Final = logging.getLogger("pgqueuer")
-logger.setLevel(level=os.environ.get("LOGLEVEL", "INFO").upper())
+logger.addHandler(logging.NullHandler())