added json logger

modules/logger.py

@@ -0,0 +1,96 @@
+"""
+loggerdabn.py
+
+This module provides functionality for setting up a centralized logging system using the
+`logging` library and the `python-json-logger` to output logs in JSON format. It handles
+log rotation by renaming old log files and saving them based on the first timestamp entry.
+
+Functions:
+- log_format(keys): Generates the logging format string based on the list of keys.
+- rotate_log_file(): Handles renaming the existing log file to a timestamp-based name.
+- setup_logger(): Configures the logging system, applies a JSON format, and returns a logger instance.
+"""
+
+import logging
+import os
+import json
+from datetime import datetime
+from pythonjsonlogger import jsonlogger
+
+# Constants for file paths and exclusions
+if __package__ is None:
+    PACKAGE = ""
+else:
+    PACKAGE = __package__
+SCRIPTDIR = os.path.abspath(os.path.dirname(__file__).removesuffix(PACKAGE))
+LOG_DIR = os.path.join(SCRIPTDIR, "logs")
+LATEST_LOG_FILE = os.path.join(LOG_DIR, "latest.jsonl")
+
+if not os.path.exists(LOG_DIR):
+    os.makedirs(LOG_DIR)
+
+
+def log_format(keys):
+    """
+    Generates a list of format strings based on the given keys.
+
+    Args:
+        keys (list): A list of string keys that represent the log attributes (e.g., 'asctime', 'levelname').
+
+    Returns:
+        list: A list of formatted strings for each key, in the format "%(key)s".
+    """
+    return [f"%({i})s" for i in keys]
+
+
+def rotate_log_file():
+    """
+    Renames the existing 'latest.jsonl' file to a timestamped file based on the first log entry's asctime.
+
+    If 'latest.jsonl' exists, it's renamed to the first timestamp found in the log entry.
+    """
+    if os.path.exists(LATEST_LOG_FILE):
+        with open(LATEST_LOG_FILE, "r", encoding="utf-8") as f:
+            first_line = f.readline()
+            try:
+                first_log = json.loads(first_line)
+                first_timestamp = first_log.get("asctime")
+                first_timestamp = first_timestamp.split(",")[0]
+            except (json.JSONDecodeError, KeyError):
+                first_timestamp = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
+
+        safe_timestamp = first_timestamp.replace(":", "-").replace(" ", "_")
+        old_log_filename = os.path.join(LOG_DIR, f"{safe_timestamp}.jsonl")
+
+        os.rename(LATEST_LOG_FILE, old_log_filename)
+
+
+def setup_logger():
+    """
+    Configures the logging system with a custom format and outputs logs in JSON format.
+
+    The logger will write to the 'logs/latest.jsonl' file, and it will include
+    multiple attributes such as the time of logging, the filename, function name, log level, etc.
+    If 'latest.jsonl' already exists, it will be renamed to a timestamped file before creating a new one.
+
+    Returns:
+        logging.Logger: A configured logger instance that can be used to log messages.
+    """
+    rotate_log_file()
+    app_logger = logging.getLogger()
+
+    supported_keys = ["asctime", "created", "filename", "funcName", "levelname", "levelno", "lineno", "module", "msecs", "message", "name", "pathname", "process", "processName", "relativeCreated", "thread", "threadName", "taskName"]
+
+    custom_format = " ".join(log_format(supported_keys))
+    formatter = jsonlogger.JsonFormatter(custom_format)
+
+    log_handler = logging.FileHandler(LATEST_LOG_FILE)
+    log_handler.setFormatter(formatter)
+
+    app_logger.addHandler(log_handler)
+    app_logger.setLevel(logging.INFO)
+
+    return app_logger
+
+
+logger = setup_logger()