app_logger.py

# Description: Setup for logging used throughout the application

import config
import logging
import os

# If it does not exist already, create a directory where we will store disk
# logs generated by the logging module
log_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), "logs")
if not os.path.exists(log_dir):
    os.mkdir(log_dir)

log_file_name = "NBC_Primary.log"
log_file_path = os.path.join(log_dir, log_file_name)

log_format = "%(asctime)s [%(levelname)s] [%(name)s] [%(filename)s/%(funcName)s(%(lineno)d)] :: %(message)s"

# Fetch logger level defined (as string) in our config file
level_text = config.LOG_LEVEL.upper()

# Define logging levels that correspond with level_text
logging_levels = {
    "CRITICAL": logging.CRITICAL,
    "ERROR": logging.ERROR,
    "WARNING": logging.WARNING,
    "INFO": logging.INFO,
    "DEBUG": logging.DEBUG,
}

# Convert level_text string to a level interpreted by the logging module,
# if the string does not match any defined in logging_levels then use
# INFO as a fallback
log_level = logging_levels.get(level_text)
if log_level is None:
    level_text = "INFO"
    log_level = logging.INFO


def get_file_handler():
    # RotatingFileHandler was producing WinError 32 (PermissionError)
    # It seems that my intended use-case is not applicable to multiple
    # Rotating Handlers (at least on Windows)
    # TODO: Will need to do more testing on Linux-based system
    file_handler = logging.FileHandler(
        filename=log_file_path,
        encoding="utf-8",
        mode="a",  # Append new logs to existing file
    )
    # Individual handlers can be set to listen only to specific level or above
    # Useful if ever plan to add a StreamHandler for example
    file_handler.setLevel(logging.DEBUG)
    file_handler.setFormatter(logging.Formatter(log_format))
    return file_handler


def get_logger(name):
    logger = logging.getLogger(name)
    logger.setLevel(log_level)
    logger.addHandler(get_file_handler())
    return logger


logger = get_logger(__name__)
logger.info(
    f"Sucessfully configured {__name__} with the "
    "following parameters:"
)
logger.info(
    f"> Logging Level: {level_text}"
)
logger.info(
    f"> File Path: {log_file_path}"
)