web.py and wsgi problem

[Katafalkas]

Hey,
So we are trying to wrap raven.middleware around our WSGI application. The problem is that when we do - raven still does not send exceptions to Sentry. raven test worked fine, so we are sure there is a connection to Sentry server.I did some debugging in raven.middleware and found out that our web.py WSGI application does not trigger any of the cases that call self.handle_exception(environ). I did slight modification on the call method:

def __call__(self, environ, start_response):
        try:
        iterable = self.application(environ, start_response)
        except Exception:
            self.handle_exception(environ)
            raise

        try:
            for event in iterable:
                yield event
        except Exception:
            self.handle_exception(environ)

            raise
        finally:
            # wsgi spec requires iterable to call close if it exists
            # see http://blog.dscpl.com.au/2012/10/obligations-for-calling-close-on.html
            if iterable and hasattr(iterable, 'close') and callable(iterable.close):
                try:
                    iterable.close()
                except Exception:
                    self.handle_exception(environ)
            else:
                print "Force handle exception"
                self.handle_exception(environ)

The last else did work. And the Exception did get to the Sentry. The exception was empty. Just the name.

So the question here: is this a web.py issue ? or Raven. I am aware that raven is working according all WSGI specifications, but we did try using NewRelic before, and their wrapper worked just fine.

I will post similar issue on web.py repo as well. Hopefully we will figure something out.

[dcramer]

My intuition is telling me that whatever is under Sentry (e.g. the web.py middleware) is catching the exception, which is why handle_exception would actually have some data here.

Basically you print sys.exc_info() and you can get the last exception unless its been cleaned up.

[Katafalkas]

So I have done some testing with sys.exc_info() and it looks like it is clean at every stage.
So if we will draw the stack like this:

  app
    |
web.py
    |
raven
    |
uWSGI

somehow, exceptions do reach uWSGI, but at the raven stage they are clean. not sure how it works

[Katafalkas]

Hey,

There was a problem with web.py. My colleague wrote this web.py client.
#353

[xordoquy]

Given #353 has been merged, do you think we could close this issue ?

[xordoquy]

Feel free to reopen this issue if needed.