Update outdated aiohttp middleware

[halfdanrump]

This:

from ddtrace.contrib.aiohttp import trace_app
from ddtrace import tracer, patch
patch(aiohttp=True)  # patch third-party modules like aiohttp_jinja2

causes this

DeprecationWarning: old-style middleware "<function trace_middleware at 0x1117ac2f0>" deprecated, see #2252
  self._middlewares_handlers = tuple(self._prepare_middleware())

when running pytest. I confirmed that the code is indeed using outdated middleware. See aiohttp docs for new-style middleware.

[labbati]

Hi @halfdanrump, thanks for taking some time to look into this issue. We will look into it as soon as possible. No workarounds are currently needed, as I can tell, as this is just a deprecation and it still work (based on aio-libs/aiohttp#2252). Something we want to address, though! In the meantime, any PR is well welcomed 😄

[labbati]

Also, this PR will resolve this issue: https://github.com/DataDog/dd-trace-py/pull/294/files#diff-4486ecdada144080e284937d7892bd76L16
Currently still work in progress, so I am not closing this issue for now.

[halfdanrump]

Hi @labbati ,

Thanks for getting back to me! Cool, I don't mind to wait for the PR. As you say it's just a deprecation warning, so it's not a big deal. Mostly makes our test suite yellow instead of nice and green 😆 Will the PR work for aiohttp 3.x though? The PR code seems to have an extra @asyncio.coroutine decorator. At least that's not required in 3.x.

[labbati]

hey @halfdanrump:

makes our test suite yellow instead of nice and green

I know that feeling, it hurts 😄 but will come soon

Will the PR work for aiohttp 3.x though

Support for 3.x is in our radar, but it probably goes beyond the PR i linked. BTW, while we do not officially test such version, did you try to use it? Any specific error?

The PR code seems to have an extra @asyncio.coroutine decorator. At least that's not required in 3.x.

Actually that could be removed, I guess, as a part of 3.x support, as it is not required and is deprecated

[stj]

Created PR #805, with a different approach (it duplicates more code). Happy to address any feedback.

Next release of aiohttp will drop the old style middleware, would like to get dd-trace-py into a state that will allow us to update and test against aiohttp master.

[majorgreys]

#294 has begun work on this. We will update this issue once it is merged.

[Kyle-Verhoog]

Done! #3362