Logging

In SSH, the LogLevel option allows you to control the level of logging information generated by the SSH client and server.
There are several log levels you can use to adjust the verbosity of SSH logging. Here are the most commonly used log levels:

QUIET:
Suppresses all log messages, except for fatal errors. It provides the least amount of information.
FATAL:
Logs only fatal errors, indicating severe issues that may prevent the SSH session from being established.
ERROR:
Logs error messages, which are issues that might cause problems but don't necessarily prevent the session from being established.
INFO:
Logs informational messages, such as connection status and key exchange details. This is the default log level.
VERBOSE:
Provides more detailed logging than INFO, including additional debugging information.
DEBUG:
Generates detailed debugging messages. This level is useful when diagnosing connection and authentication issues.
DEBUG1, DEBUG2, DEBUG3:
Provides even more verbose debugging output, with DEBUG3 being the most detailed.

cat ~/.ssh/config
  Host *
    LogLevel QUIET
    LogLevel FATAL
    LogLevel ERROR
    LogLevel INFO
    LogLevel VERBOSE
    LogLevel DEBUG
    LogLevel DEBUG1
    LogLevel DEBUG2
    LogLevel DEBUG3
    ...

cat <<'EOF'> config.py
LOGGER_MAX_FILE_LENGTH = 10
EOF

mkdir src
cat <<'EOF'> src/logger.py
import logging
import datetime
import sys

from config import *

if isinstance(LOGGER_MAX_FILE_LENGTH, int):
    LOGGER_MAX_FILE_LENGTH = str(LOGGER_MAX_FILE_LENGTH)


def get_now() -> str:
    #
    # choose your format
    #
    current_time = datetime.datetime.now()

    # 2023-07-16 22:16:15.958
    formatted_time_1 = current_time.strftime("%Y-%m-%d %H:%M:%S.%f")[:-3]

    # 22:16:54.471
    formatted_time_2 = current_time.strftime("%H:%M:%S.%f")[:-3]

    # 22:17:21
    formatted_time_3 = current_time.strftime("%H:%M:%S")

    return formatted_time_2


class ExitOnCriticalHandler(logging.Handler):
    def emit(self, record):
        # Unset Color
        COLOR = RESET = "\033[0m"

        # Debug -> Black
        if record.levelno == logging.DEBUG:
            COLOR = "\033[0m"
        # Info -> Green
        elif record.levelno == logging.INFO:
            COLOR = "\033[92m"
        # Warn -> Blue
        elif record.levelno == logging.WARNING:
            COLOR = "\033[94m"
        # Error -> Orange
        elif record.levelno == logging.ERROR:
            COLOR = "\033[38;5;208m"
        # Critical -> Red
        elif record.levelno >= logging.CRITICAL:
            COLOR = "\033[91m"

        # Custom Line
        print(
            COLOR
            + "{:} {:} {:04} {:{w}} {:}".format(
                get_now(),
                record.levelname,
                record.lineno,
                record.filename,
                record.msg,
                w=LOGGER_MAX_FILE_LENGTH,
            )
            + RESET
        )

        # Exit on Critical
        if record.levelno >= logging.CRITICAL:
            logging.shutdown()
            print("\033[91m" + "GOT A CRITICAL -> EXIT HERE!" + "\033[0m")
            sys.exit()


# Init Logger
logger = logging.getLogger()
logger.setLevel(logging.INFO)

# Create and add the custom handler
exit_handler = ExitOnCriticalHandler()
logger.addHandler(exit_handler)


# Set Log Level
def set_log_level(level: str):
    # Parse/ Set LogLevel
    if level.lower() in ["d", "debug"]:
        logger.setLevel(logging.DEBUG)
    elif level.lower() in ["i", "info"]:
        logger.setLevel(logging.INFO)
    elif level.lower() in ["w", "warning"]:
        logger.setLevel(logging.WARNING)
    elif level.lower() in ["e", "error"]:
        logger.setLevel(logging.ERROR)
    elif level.lower() in ["c", "critical"]:
        logger.setLevel(logging.CRITICAL)

    # Custom level name mappings, Debug -> D
    logging.addLevelName(logging.DEBUG, "D")
    logging.addLevelName(logging.INFO, "I")
    logging.addLevelName(logging.WARNING, "W")
    logging.addLevelName(logging.ERROR, "E")
    logging.addLevelName(logging.CRITICAL, "C")


# Functions to Call
def ldebug(msg: str):
    logger.debug(msg)


def linfo(msg: str):
    logger.info(msg)


def lwarning(msg: str):
    logger.warning(msg)


def lerror(msg: str):
    logger.error(msg)


def lcritical(msg: str):
    logger.critical(msg)
EOF