Sanic Integration: Handled exceptions get captured and sent to sentry

[simonlindroosfyndiq]

Hi,

I have an issue that the Sanic integration is capturing and sending exceptions to Sentry even though I have declared an exception handler using the @app.exception decorator as described here Sanic Exceptions. I have created a sample application that reproduces this issue. The Sentry DSN key is provided in the SENTRY_DSN environment variable. I have tried this using python 3.7.5, 3.8.0 and 3.8.5 as well as with older versions of the sentry_sdk library without success. I have found that the exception is being sent to sentry before the code reaches the error handler, noted by the comment in the code below.

Note that if I remove the SanicIntegration() during initialisation of the sentry_sdk, the application behaves as expected. Only unhandled exceptions are sent to Sentry but with less context about the exception.

Is this an expected behaviour given the sample application I provided?

Application code app.py:

import os

import sentry_sdk
from sanic import Sanic, response
from sentry_sdk.integrations.sanic import SanicIntegration

sentry_sdk.init(
    dsn=os.environ['SENTRY_DSN'], environment='dev', integrations=[SanicIntegration()], debug=True
)
app = Sanic(__name__)

class CustomException(Exception):
    pass

@app.route('/custom_error')
async def get(request):
    raise CustomException()

@app.exception(CustomException)
async def custom_error_handler(request, exception):
    # Exception has already been captured and sent to Sentry when we reach this point
    message = {'description': 'Custom Exception'}
    return response.json(message, status=401)

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8000, debug=True, auto_reload=False, workers=1)

Web server start command and logs:

$ python app.py
 [sentry] DEBUG: Setting up integrations (with default = True)
 [sentry] DEBUG: Setting up previously not enabled integration sanic
 [sentry] DEBUG: Setting up previously not enabled integration logging
 [sentry] DEBUG: Setting up previously not enabled integration stdlib
 [sentry] DEBUG: Setting up previously not enabled integration excepthook
 [sentry] DEBUG: Setting up previously not enabled integration dedupe
 [sentry] DEBUG: Setting up previously not enabled integration atexit
 [sentry] DEBUG: Setting up previously not enabled integration modules
 [sentry] DEBUG: Setting up previously not enabled integration argv
 [sentry] DEBUG: Setting up previously not enabled integration threading
 [sentry] DEBUG: Enabling integration sanic
 [sentry] DEBUG: Enabling integration logging
 [sentry] DEBUG: Enabling integration stdlib
 [sentry] DEBUG: Enabling integration excepthook
 [sentry] DEBUG: Enabling integration dedupe
 [sentry] DEBUG: Enabling integration atexit
 [sentry] DEBUG: Enabling integration modules
 [sentry] DEBUG: Enabling integration argv
 [sentry] DEBUG: Enabling integration threading
[2020-08-24 10:08:41 +0200] [7391] [DEBUG]

                 Sanic
         Build Fast. Run Fast.

[2020-08-24 10:08:41 +0200] [7391] [INFO] Goin' Fast @ http://0.0.0.0:8000
[2020-08-24 10:08:41 +0200] [7391] [INFO] Starting worker [7391]
[2020-08-24 10:08:47 +0200] - (sanic.access)[INFO][127.0.0.1:55202]: GET http://localhost:8000/custom_error  401 34
 [sentry] DEBUG: Sending event, type:null level:error event_id:<REDACTED> project:<REDACTED> host:<REDACTED>.ingest.sentry.io

curl command

$ curl -i http://localhost:8000/custom_error
HTTP/1.1 401 Unauthorized
Connection: keep-alive
Keep-Alive: 5
Content-Length: 34
Content-Type: application/json

{"description":"Custom Exception"}

pip freeze output

aiofiles==0.5.0
certifi==2020.6.20
chardet==3.0.4
click==7.1.2
h11==0.8.1
h2==3.2.0
hpack==3.0.0
hstspreload==2020.8.18
httptools==0.1.1
httpx==0.9.3
hyperframe==5.2.0
idna==2.10
multidict==4.7.6
pip-tools==5.3.1
rfc3986==1.4.0
sanic==19.12.2
sentry-sdk==0.16.5
six==1.15.0
sniffio==1.1.0
ujson==3.1.0
urllib3==1.25.10
uvloop==0.14.0
websockets==8.1

[untitaker]

This is currently intended behavior, but we could probably implement a similar solution to #303

[simonlindroosfyndiq]

Thank you for you answer, we did not expect this to be the expected behaviour. For now we will remove the SanicIntegration for our team to proceed.

[untitaker]

Sanic integration adds request data to your events so you'll lose some product value from disabling it. I'd recommend using the before_send hook to filter out CustomException: https://docs.sentry.io/error-reporting/configuration/filtering/?platform=python#before-send

Instead of setting a fingerprint you'd return None to drop the event.

[j-boivie]

I've come across this as well, and I'm a bit surprised that this is the intended behavior. The docs for the Sanic integration say:

All exceptions leading to an Internal Server Error are reported.

I took this to mean that all exceptions that result in a 500 visible to a user would be reported, but perhaps I misunderstood? We're using custom exception handlers to handle 4xx errors, that shouldn't be logged to Sentry (which I think is a fairly common pattern?), but this makes that difficult.

[github-actions[bot]]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

---

"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀

[antonpirker]

Hello @simonlindroosfyndiq and @j-boivie ! Just a quick update: I think it would be good if we would have the behavior similar to the one described in https://github.com/getsentry/sentry-python/issues/303 like @untitaker suggested.

(so basically only send unhandled exceptions to Sentry)

So, anyone of you (or anyone else from the Sanic community) is motivated and also has the time to provide a PR for this? (In Sentry we will not be able to implement this in the next couple of months, I am afraid)

[github-actions[bot]]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

---

"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀