python app with loggin to rsyslog

logger-rsyslog.py

"""

rsyslog config: /etc/rsyslog.d/my-sample.conf:
$template AppLogFormat, "%TIMESTAMP:::date-pgsql%%TIMESTAMP:27:32:date-rfc3339%(%syslogseverity-text%)%msg%\n"
if $app-name == 'my-sample-app' then -/var/log/my-sample-app/app.log;AppLogFormat
& ~

"""

from __future__ import print_function
import argparse
import logging
import logging.handlers

APP_NAME = "my-sample-app"


def create_logger(app_name, log_level=logging.DEBUG, stdout=True, syslog=False, file=False):
    """
    create logging object with logging to syslog, file and stdout
    :param app_name app name
    :param log_level logging log level
    :param stdout log to stdout
    :param syslog log to syslog
    :param file log to file
    :return: logging object
    """
    # disable requests logging
    #logging.getLogger("requests").setLevel(logging.ERROR)
    #logging.getLogger("urllib3").setLevel(logging.ERROR)

    # create logger
    logger = logging.getLogger(app_name)
    logger.setLevel(log_level)

    # set log format to handlers
    formatter = logging.Formatter('%(name)s - %(asctime)s - %(levelname)s - %(message)s')

    if file:
        # create file logger handler
        fh = logging.FileHandler('my-sample-app.log')
        fh.setLevel(log_level)
        fh.setFormatter(formatter)
        logger.addHandler(fh)

    if syslog:
        # create syslog logger handler
        sh = logging.handlers.SysLogHandler(address='/dev/log')
        sh.setLevel(log_level)
        sf = logging.Formatter('%(name)s: %(message)s')
        sh.setFormatter(sf)
        logger.addHandler(sh)

    if stdout:
        # create stream logger handler
        ch = logging.StreamHandler()
        ch.setLevel(log_level)
        ch.setFormatter(formatter)
        logger.addHandler(ch)

    return logger


if __name__ == "__main__":
    print("BEGIN")

    parser = argparse.ArgumentParser(description='sample app with logging')
    parser.add_argument('-s', '--stdout', action='store_true', default=True, help='log to stdout')
    parser.add_argument('-r', '--rsyslog', action='store_true', default=False, help='log to syslog')
    parser.add_argument('-f', '--file', action='store_true', default=False, help='log file app.log')

    args = parser.parse_args()

    log = create_logger(
        app_name=APP_NAME,
        log_level=logging.DEBUG,
        syslog=args.rsyslog,
        stdout=args.stdout,
        file=args.file)

    log.debug("hello debug from my sample app")
    log.debug("hello error from my sample app")

    print("END")

Awesome!

You have used $app-name in /etc/rsyslog.d/my-sample.conf
How it actually work?
How does configuration file got to know that variable?
From where it gets it value?
Can you share any reference for writing such configuration files?

Hi! $app-mame is part of rsyslog template https://www.rsyslog.com/doc/v8-stable/configuration/templates.html
It is filled by python logging formatter.
In my example code, it is filled with value of app_name parameter in create_logger

how your conf file matches that name with python code? I changed the $app-name with another name which didn't executed.

…

On Fri, Jun 7, 2019 at 1:17 PM Daniel Kraic ***@***.***> wrote: Hi! $app-mame is part of rsyslog template — You are receiving this because you commented. Reply to this email directly, view it on GitHub <https://gist.github.com/a1657f19bad9c158cbf9532e1ed1503b?email_source=notifications&email_token=AISEHCJ6LUIOQN5XQOYZBRLPZIHAXA5CNFSM4HVRRQA2YY3PNVWWK3TUL52HS4DFVNDWS43UINXW23LFNZ2KUY3PNVWWK3TUL5UWJTQAFTJHY#gistcomment-2937468>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AISEHCJSFLCANEINEDI74NTPZIHAXANCNFSM4HVRRQAQ> .

Sorry, $app-mame is one of rsyslog properties - it is data item from log message: https://www.rsyslog.com/doc/v8-stable/configuration/properties.html
In python code syslog message is created using logging formatter. Part of this message is also app name. Message is then send to syslog (via /dev/log unix socket). Rsyslog service will read and parse received message and fill rsyslog properties from this message.

Ok, I got it. Thank you very much for sharing this information with me.

…

On Sun, Jun 9, 2019 at 9:56 PM Daniel Kraic ***@***.***> wrote: Sorry, $app-mame is one of rsyslog properties - it is data item from log message: https://www.rsyslog.com/doc/v8-stable/configuration/properties.html In python code syslog message is created using logging formatter. Part of this message is also app name. Message is then send to syslog (via /dev/log unix socket). Rsyslog service will read and parse received message and fill rsyslog properties from this message. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <https://gist.github.com/a1657f19bad9c158cbf9532e1ed1503b?email_source=notifications&email_token=AISEHCMEHCOCESZFQAX57WLPZUVLBA5CNFSM4HVRRQA2YY3PNVWWK3TUL52HS4DFVNDWS43UINXW23LFNZ2KUY3PNVWWK3TUL5UWJTQAFTMKS#gistcomment-2939049>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AISEHCJ2YBBJSDYEVEWPCZ3PZUVLBANCNFSM4HVRRQAQ> .