flask with logging

flask_logging.py

# https://rz0r.net/post/2019-05-27-flask-logging/
import os
import logging
import socket
from flask import Flask
from logging.config import dictConfig

class ContextFilter(logging.Filter):
    hostname = socket.gethostname()

    def filter(self, record):
        record.hostname = ContextFilter.hostname
        return True

logging_configuration = dict(
    version=1,
    disable_existing_loggers=False,
    formatters={
        "default": {"format": "[%(hostname)s %(asctime)s] %(levelname)s in %(module)s: %(message)s"},
    },
    filters={"hostname_filter": {"()": ContextFilter}},
    handlers={
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "default",
            "filters": ["hostname_filter"],
        }
    },
    root={"handlers": ["console"], "level": os.getenv("LOG_LEVEL", "INFO")},
)

dictConfig(logging_configuration)
app = Flask(__name__)
logger = logging.getLogger(__name__)


@app.route("/")
def home():
    logger.debug("debug message")
    logger.info("info message")
    logger.warning("warning message")
    logger.error("error message")
    logger.critical("critical error message")
    return "Hello World"


if __name__ == "__main__":
    app.run()