Some settings don't appear to work with "Custom Application"

[truh]

I have a FastAPI application that I run with gunicorn with a runner similar to https://docs.gunicorn.org/en/stable/custom.html.

I'm trying to print some header values to I added "access_log_format": '%({user-agent}i)s' to the options dict. To my surprise the access log is the same as it is without that line.

Some other settings also didn't work. For example adding "print_config": True, doesn't do anything.
Some settings like bind, workers, worker_class, accesslog appear to work fine.

[pajod]

access_log_format #worksforme

And print_config one is part of Application, not BaseApplication - but you can easily add it back if you want it, like so:

import gunicorn.app.base

def handler_app(environ, start_response):
    start_response("200 OK", [])
    return [b'Works.']

class StandaloneApplication(gunicorn.app.base.BaseApplication):
    def __init__(self, app, options=None):
        self.options = options or {}
        self.application = app
        super().__init__()
    def load_config(self):
        config = {key: value for key, value in self.options.items()
                  if key in self.cfg.settings and value is not None}
        for key, value in config.items():
            self.cfg.set(key.lower(), value)
    def load(self):
        return self.application
    def run(self):
        if self.cfg.print_config:  # <<<<<<<<<<<<<<<<<<<<<<< print_config added here
            print(self.cfg)
        super().run()

if __name__ == '__main__':
    options = {
        'bind': '%s:%s' % ('[::1]', '8080'),
        'workers': 1,
        "print_config": True,
        "access_log_format": 'this is my custom log format - %({user-agent}i)s',
        "enable_stdio_inheritance": True,
        "accesslog": "-",
        "errorlog": "-",
    }
    StandaloneApplication(handler_app, options).run()

# python3 app.py
access_log_format                  = this is my custom log format - %({user-agent}i)s
[..]
[2025-04-08 19:39:28 +0200] [401927] [INFO] Starting gunicorn 23.0.0
[2025-04-08 19:39:28 +0200] [401927] [INFO] Listening at: http://[::1]:8080 (401927)
[2025-04-08 19:39:28 +0200] [401927] [INFO] Using worker: sync
[2025-04-08 19:39:28 +0200] [401929] [INFO] Booting worker with pid: 401929
# echo -ne "GET / HTTP/1.1\r\nUser-Agent: foo\r\n\r\n" | nc.openbsd "::1" 8080
this is my custom log format - foo

[truh]

Good to know that I need to implement print_config myself. Maybe that part lead me to incorrect assumptions about the rest of my application as well.