fx-private-relay/gunicorn.conf.py

import os

for k, v in os.environ.items():
    if k.startswith("GUNICORN_"):
        key = k.split("_", 1)[1].lower()
        locals()[key] = v


if "PORT" in os.environ:
    locals()["bind"] = "0.0.0.0:{}".format(os.environ["PORT"])