logger is logging multiple times

[bluebrown]

Hi, I am using flask and the logger is logging up to 4 times depedning on what im doing there. All i want is to set some configuration. It seems like every interaction with the logging module creates another handler or something.

app = flask.Flask(__name__)
json_logging.init_flask(enable_json=True)
json_logging.init_request_instrument(
    app, exclude_url_patterns=[r'/ready', r'/alive'])

app.logger.setLevel(logging.getLevelName(env.get('LOGLEVEL', 'INFO').upper()))
app.logger.addHandler(logging.StreamHandler(sys.stdout))
app.logger.removeHandler(default_handler)

app.config["MONGO_URI"] = env.get("MONGO_DSN")

client = MongoClient(app.config["MONGO_URI"])
app.logger.debug(client.server_info())

[bobbui]

@bluebrown can u provide a fully working code sample

[bluebrown]

That is a working example, all what's missing is the import statements., which I though I can leave out for brevity as they are apparent.

I made it even smaller now.

import flask
from os import environ as env
from pymongo import MongoClient
import json_logging
import logging

app = flask.Flask(__name__)
json_logging.init_flask(enable_json=True)
json_logging.init_request_instrument(
    app, exclude_url_patterns=[r'/ready', r'/alive'])

app.logger.setLevel(logging.getLevelName(env.get('LOGLEVEL', 'INFO').upper()))

app.config["MONGO_URI"] = env.get("MONGO_DSN")

client = MongoClient(app.config["MONGO_URI"])
app.logger.debug(client.server_info())

I m doing further testing and I noticed something. When I run this via the below I dont seem to get duplicates.

python -m flask run --host 0.0.0.0

When I use gunicorn it will duplicate but only in the entry point. Logs from other modules than the entrypoint are not double.

gunicorn \
    --worker-tmp-dir=/dev/shm \
    --workers=2 \
    --threads=4 \
    --worker-class=gthread  \
    --bind=0.0.0.0:5000 \
    --log-level=${LOGLEVEL} \
    app:app

Now I actually hav tried to set the --workers=1 and there is no duplicate anymore. I havn tested fully but it seems at least related.