FastAPI gunicon uvicorn access_log format customization - gunicorn

Question

We are using the https://github.com/tiangolo/uvicorn-gunicorn-fastapi-docker FastAPI and were able to customize our logging with a gunicorn logging file.
However, we are not able to change the details of the %(message)s attribute as defined in the documentation access log - https://docs.gunicorn.org/en/stable/settings.html#accesslog.
We receive an error postet below, that the keys are unknown.
A similar question has been asked before and received many upvotes.
gunicorn log-config access_log_format
What are we doing wrong?
#start.sh
# Start Gunicorn
exec gunicorn -k uvicorn.workers.UvicornWorker -c "$GUNICORN_CONF" "$APP_MODULE" --log-config "/logging.conf"
[loggers]
keys=root, gunicorn.error, gunicorn.access,uvicorn.error,uvicorn.access
[handlers]
keys=console, error_file, access_file, access_filegunicorn
[formatters]
keys=generic, access, accessgunicorn
[logger_root]
level=INFO
handlers=console
propagate=1
[logger_gunicorn.error]
level=INFO
handlers=error_file
propagate=0
qualname=gunicorn.error
[logger_gunicorn.access]
level=INFO
handlers=access_filegunicorn
propagate=0
qualname=gunicorn.access
[logger_uvicorn.error]
level=INFO
handlers=error_file
propagate=0
qualname=uvicorn.error
[logger_uvicorn.access]
level=INFO
handlers=access_file
propagate=0
qualname=uvicorn.access
[handler_console]
class=StreamHandler
formatter=generic
args=(sys.stdout, )
[handler_error_file]
class=StreamHandler
formatter=generic
args=(sys.stdout, )
[handler_access_file]
class=StreamHandler
formatter=access
args=(sys.stdout, )
[handler_access_filegunicorn]
class=StreamHandler
formatter=accessgunicorn
args=(sys.stdout, )
[formatter_generic]
format=[%(levelname)s]: %(message)s
datefmt=%Y-%m-%dT%H:%M:%S
class=logging.Formatter
[formatter_access]
format=[%(levelname)s]: %(message)s
datefmt=%Y-%m-%dT%H:%M:%S
class=logging.Formatter
[formatter_accessgunicorn]
format=[%(levelname)s]: '{"remote_ip":"%(h)s","session_id":"%({X-Session-Id}i)s","status":"%(s)s","request_method":"%(m)s","request_path":"%(U)s","request_querystring":"%(q)s","request_timetaken":"%(D)s","response_length":"%(B)s", "remote_addr": "%(h)s"}'
datefmt=%Y-%m-%dT%H:%M:%S
class=logging.Formatter
Message: '%s - "%s %s HTTP/%s" %d'
Arguments: ('213.3.14.24:53374', 'GET', '/v1/docs', '1.1', 200)
--- Logging error ---
Traceback (most recent call last):
File "/usr/local/lib/python3.7/logging/__init__.py", line 1025, in emit
msg = self.format(record)
File "/usr/local/lib/python3.7/logging/__init__.py", line 869, in format
return fmt.format(record)
File "/usr/local/lib/python3.7/logging/__init__.py", line 611, in format
s = self.formatMessage(record)
File "/usr/local/lib/python3.7/logging/__init__.py", line 580, in formatMessage
return self._style.format(record)
File "/usr/local/lib/python3.7/logging/__init__.py", line 422, in format
return self._fmt % record.__dict__
KeyError: 'h'
Call stack:
File "/usr/local/bin/gunicorn", line 8, in <module>
sys.exit(run())
File "/usr/local/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 58, in run
WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
File "/usr/local/lib/python3.7/site-packages/gunicorn/app/base.py", line 228, in run
super().run()
File "/usr/local/lib/python3.7/site-packages/gunicorn/app/base.py", line 72, in run
Arbiter(self).run()
File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 202, in run
self.manage_workers()
File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 545, in manage_workers
self.spawn_workers()
File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 616, in spawn_workers
self.spawn_worker()
File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 583, in spawn_worker
worker.init_process()
File "/usr/local/lib/python3.7/site-packages/uvicorn/workers.py", line 61, in init_process
super(UvicornWorker, self).init_process()
File "/usr/local/lib/python3.7/site-packages/gunicorn/workers/base.py", line 140, in init_process
self.run()
File "/usr/local/lib/python3.7/site-packages/uvicorn/workers.py", line 70, in run
loop.run_until_complete(server.serve(sockets=self.sockets))
File "/usr/local/lib/python3.7/site-packages/uvicorn/protocols/http/httptools_impl.py", line 385, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/usr/local/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/site-packages/fastapi/applications.py", line 171, in __call__
await super().__call__(scope, receive, send)
File "/usr/local/lib/python3.7/site-packages/starlette/applications.py", line 102, in __call__
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/usr/local/lib/python3.7/site-packages/starlette/middleware/cors.py", line 78, in __call__
await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/usr/local/lib/python3.7/site-packages/starlette/routing.py", line 550, in __call__
await route.handle(scope, receive, send)

Answer 1

I found very useful information here https://github.com/tiangolo/fastapi/issues/1508
I needed to add the request datetime , and the solution that I implemented was:
#app.on_event("startup")
async def startup_event():
logger = logging.getLogger("uvicorn.access")
console_formatter = uvicorn.logging.ColourizedFormatter(
"{asctime} {levelprefix} : {message}",
style="{", use_colors=True)
logger.handlers[0].setFormatter(console_formatter)
if __name__ == "__main__":
uvicorn.run(app, host="0.0.0.0", port=8000)

Answer 2

Our solution was a customer logger written in python that is referenced in a logging.conf file
logging.conf
[loggers]
keys=root, gunicorn.error, gunicorn.access,uvicorn.error,uvicorn.access
[handlers]
keys=console, error_file, access_file, accesscustom
[formatters]
keys=generic, access, AccessFormatter
[logger_root]
level=INFO
handlers=console
propagate=1
[logger_gunicorn.error]
level=INFO
handlers=error_file
propagate=0
qualname=gunicorn.error
[logger_gunicorn.access]
level=INFO
handlers=accesscustom
propagate=0
qualname=gunicorn.access
[logger_uvicorn.error]
level=INFO
handlers=error_file
propagate=0
qualname=uvicorn.error
[logger_uvicorn.access]
level=INFO
handlers=accesscustom
propagate=0
qualname=uvicorn.access
[handler_console]
class=StreamHandler
formatter=generic
args=(sys.stdout, )
[handler_error_file]
class=StreamHandler
formatter=generic
args=(sys.stdout, )
[handler_access_file]
class=StreamHandler
formatter=access
args=(sys.stdout, )
[handler_accesscustom]
class=StreamHandler
formatter=AccessFormatter
args=(sys.stdout, )
[formatter_generic]
format=%(levelname)s: %(message)s
datefmt=%Y-%m-%dT%H:%M:%S
class=uvicorn.logging.DefaultFormatter
[formatter_access]
format=%(levelname)s: %(message)s
datefmt=%Y-%m-%dT%H:%M:%S
class=customlogger.CustomFormatter
[formatter_AccessFormatter]
format={"event":"access_log","ip":"%(h)s","status":"%(s)s","method":"%(m)s","path":"%(U)s","referer":"%(f)s","x_session_id":"%(x-session-id)s","x_google_id":"%(x-google-id)s","x_server_time":"%(x-server-time)s","agent":"%(a)s"}
datefmt=%Y-%m-%dT%H:%M:%S
class=customlogger.CustomFormatter
customlogger.py
import base64
import binascii
import http
import logging
import os
import sys
import time
from copy import copy
from datetime import datetime
from pprint import pprint
import click
TRACE_LOG_LEVEL = 5
class ColourizedFormatter(logging.Formatter):
"""
A custom log formatter class that:
* Outputs the LOG_LEVEL with an appropriate color.
* If a log call includes an `extras={"color_message": ...}` it will be used
for formatting the output, instead of the plain text message.
"""
level_name_colors = {
TRACE_LOG_LEVEL: lambda level_name: click.style(str(level_name), fg="blue"),
logging.DEBUG: lambda level_name: click.style(str(level_name), fg="cyan"),
logging.INFO: lambda level_name: click.style(str(level_name), fg="green"),
logging.WARNING: lambda level_name: click.style(str(level_name), fg="yellow"),
logging.ERROR: lambda level_name: click.style(str(level_name), fg="red"),
logging.CRITICAL: lambda level_name: click.style(
str(level_name), fg="bright_red"
),
}
def __init__(self, fmt=None, datefmt=None, style="%", use_colors=None):
if use_colors in (True, False):
self.use_colors = use_colors
else:
self.use_colors = sys.stdout.isatty()
super().__init__(fmt=fmt, datefmt=datefmt, style=style)
def color_level_name(self, level_name, level_no):
default = lambda level_name: str(level_name)
func = self.level_name_colors.get(level_no, default)
return func(level_name)
def should_use_colors(self):
return True
def formatMessage(self, record):
recordcopy = copy(record)
levelname = recordcopy.levelname
seperator = " " * (8 - len(recordcopy.levelname))
if self.use_colors:
levelname = self.color_level_name(levelname, recordcopy.levelno)
if "color_message" in recordcopy.__dict__:
recordcopy.msg = recordcopy.__dict__["color_message"]
recordcopy.__dict__["message"] = recordcopy.getMessage()
recordcopy.__dict__["levelprefix"] = levelname + ":" + seperator
return super().formatMessage(recordcopy)
class DefaultFormatter(ColourizedFormatter):
def should_use_colors(self):
return sys.stderr.isatty()
class AccessFormatter(ColourizedFormatter):
status_code_colours = {
1: lambda code: click.style(str(code), fg="bright_white"),
2: lambda code: click.style(str(code), fg="green"),
3: lambda code: click.style(str(code), fg="yellow"),
4: lambda code: click.style(str(code), fg="red"),
5: lambda code: click.style(str(code), fg="bright_red"),
}
def get_client_addr(self, scope):
client = scope.get("client")
if not client:
return ""
return "%s:%d" % (client[0], client[1])
def get_path(self, scope):
return scope.get("root_path", "") + scope["path"]
def get_full_path(self, scope):
path = scope.get("root_path", "") + scope["path"]
query_string = scope.get("query_string", b"").decode("ascii")
if query_string:
return path + "?" + query_string
return path
def get_status_code(self, record):
status_code = record.__dict__["status_code"]
try:
status_phrase = http.HTTPStatus(status_code).phrase
except ValueError:
status_phrase = ""
status_and_phrase = "%s %s" % (status_code, status_phrase)
if self.use_colors:
default = lambda code: status_and_phrase
func = self.status_code_colours.get(status_code // 100, default)
return func(status_and_phrase)
return status_and_phrase
def formatMessage(self, record):
recordcopy = copy(record)
scope = recordcopy.__dict__["scope"]
method = scope["method"]
path = self.get_path(scope)
full_path = self.get_full_path(scope)
client_addr = self.get_client_addr(scope)
status_code = self.get_status_code(recordcopy)
http_version = scope["http_version"]
request_line = "%s %s HTTP/%s" % (method, full_path, http_version)
if self.use_colors:
request_line = click.style(request_line, bold=True)
recordcopy.__dict__.update(
{
"method": method,
"path": path,
"full_path": full_path,
"client_addr": client_addr,
"request_line": request_line,
"status_code": status_code,
"http_version": http_version,
}
)
return super().formatMessage(recordcopy)
class SafeAtoms(dict):
def __init__(self, atoms):
dict.__init__(self)
for key, value in atoms.items():
if isinstance(value, str):
self[key] = value.replace('"', '\\"')
else:
self[key] = value
def __getitem__(self, k):
if k.startswith("{"):
kl = k.lower()
if kl in self:
return super().__getitem__(kl)
else:
return "-"
if k in self:
return super().__getitem__(k)
else:
return '-'
class CustomFormatter(AccessFormatter):
atoms_wrapper_class = SafeAtoms
def now(self):
""" return date in Apache Common Log Format """
return time.strftime('[%d/%b/%Y:%H:%M:%S %z]')
def _get_user(self, environ):
user = None
http_auth = environ.get("HTTP_AUTHORIZATION")
if http_auth and http_auth.lower().startswith('basic'):
auth = http_auth.split(" ", 1)
if len(auth) == 2:
try:
# b64decode doesn't accept unicode in Python < 3.3
# so we need to convert it to a byte string
auth = base64.b64decode(auth[1].strip().encode('utf-8'))
# b64decode returns a byte string
auth = auth.decode('utf-8')
auth = auth.split(":", 1)
except (TypeError, binascii.Error, UnicodeDecodeError) as exc:
self.debug("Couldn't get username: %s", exc)
return user
if len(auth) == 2:
user = auth[0]
return user
def atoms(self, environ, request_time, scope, statuscode, created):
headers = dict(scope.get('headers',[('-','-')]))
response_headers = dict(scope.get('response_headers',[('-','-')]))
atoms = {
'h': scope.get("client", ('-', ''))[0],
'l': '-',
's': statuscode,
'u': self._get_user(environ) or '-',
't': created,
'm': str(scope.get("method", "-")),
'U': scope.get("path", "-"),
'q': scope.get("query_string", "-").decode("utf-8"),
'H': str(scope.get("type", "-")),
'f': headers.get(b"referer", b"-").decode("utf-8"),
'a': headers.get(b"user-agent", b"-").decode("utf-8"),
'x-session-id': headers.get(b"x-session-id", b"-").decode("utf-8"),
'x-google-id': headers.get(b"x-google-id", b"-").decode("utf-8"),
'x-server-time': response_headers.get(b"x-server-time", b"").decode("utf-8"),
'p': "<%s>" % os.getpid()
}
return atoms
def formatMessage(self, record):
recordcopy = copy(record)
scope = recordcopy.__dict__["scope"]
#pprint(vars(recordcopy))
safe_atoms = self.atoms_wrapper_class(
self.atoms(os.environ, datetime.now(), scope, recordcopy.status_code, recordcopy.created)
)
recordcopy.__dict__.update(safe_atoms)
# pprint(vars(os.environ))
return super().formatMessage(recordcopy)

Answer 3

I'm also using the FastAPI - Uvicorn - Gunicorn stack.
To modify the format of the uvicorn logging, I first inspected its current configuration :
>>> from pprint import pprint
>>> import uvicorn.config
>>> pprint(uvicorn.config.LOGGING_CONFIG)
{'disable_existing_loggers': False,
'formatters': {'access': {'()': 'uvicorn.logging.AccessFormatter',
'fmt': '%(levelprefix)s %(client_addr)s - '
'"%(request_line)s" %(status_code)s'},
'default': {'()': 'uvicorn.logging.DefaultFormatter',
'fmt': '%(levelprefix)s %(message)s',
'use_colors': None}},
'handlers': {'access': {'class': 'logging.StreamHandler',
'formatter': 'access',
'stream': 'ext://sys.stdout'},
'default': {'class': 'logging.StreamHandler',
'formatter': 'default',
'stream': 'ext://sys.stderr'}},
'loggers': {'uvicorn': {'handlers': ['default'], 'level': 'INFO'},
'uvicorn.access': {'handlers': ['access'],
'level': 'INFO',
'propagate': False},
'uvicorn.error': {'level': 'INFO'}},
'version': 1}
And I created my own logging configuration based on the default configuration of uvicorn. I added the date/time of the log, and my own custom logger :
import logging
LOGGER_NAME = "myapp"
log_config = {
"version": 1,
"disable_existing_loggers": False,
"formatters": {
'access': {
'()': 'uvicorn.logging.AccessFormatter',
'fmt': '%(levelprefix)s %(asctime)s - %(client_addr)s - "%(request_line)s" %(status_code)s',
"datefmt": "%Y-%m-%d %H:%M:%S",
"use_colors": True
},
"default": {
"()": "uvicorn.logging.DefaultFormatter",
"fmt": "%(levelprefix)s %(asctime)s - %(message)s",
"datefmt": "%Y-%m-%d %H:%M:%S",
"use_colors": True
},
},
"handlers": {
'access': {
'class': 'logging.StreamHandler',
'formatter': 'access',
'stream': 'ext://sys.stdout'
},
"default": {
"formatter": "default",
"class": "logging.StreamHandler",
"stream": "ext://sys.stderr",
},
},
"loggers": {
LOGGER_NAME: {
"handlers": ["default"],
"level": "DEBUG",
"propagate": False
},
"uvicorn": {
"handlers": ["default"],
"level": "DEBUG",
"propagate": True
},
'uvicorn.access': {
'handlers': ['access'],
'level': 'INFO',
'propagate': False
},
'uvicorn.error': {
'level': 'INFO',
'propagate': False
}
},
}
def get_logger():
return logging.getLogger(LOGGER_NAME)
Then in my main.py file, where I defined app = FastAPI(...), I configure the logging just after my imports lines with :
logging.config.dictConfig(log_config)
And I do custom logging in my app by using the custom logger that I defined :
logger = get_logger()
logger.info("Hello World!")