fix(tornado): ensure reading future.result() won't throw an exception in client.py _finish_tracing_callback

[jgibo]

Description

Ensures correct handling of an exception future result from tornado http client. Before this change, an exception result would cause an exception to be raised that is not handled by the lib - which is undesired based on logic in client.py _finish_tracing_callback.

Fixes #2555

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• With tornado instrumentation enabled, use tornado http client fetch with option raise_error=True and make a request that fails (response of 404, 500, etc...). An exception in _finish_tracing_callback will be raised that is not handled above - bubbles up to the asyncio runtime.
• Unit test added to verify traced http client request failure has its span exported (indirectly verifies that _finish_tracing_callback completes successfully).
  Note: The new test class class TestTornadoHTTPClientInstrumentation can be copied to main branch, and test_http_client_failed_response will fail due to this bug.

Does This PR Require a Core Repo Change?

• No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: jgibo / name: Jordan Gibbings (632452a, 8f1a52f, 9aebb65, d3e0d25, 245c557, a13049a, 6220697, a55a22e, 4280382, ca6cfc9, d9ed843, 8256c46, dfd4198, 38ebaf6, 4d9613e, cbb3e4d, b60cfc8, 24c75ad, 516de12, 4937ee7, 18fbf80, a1a8caa, 90eb089, 9b37b88, e1963f0, 252feba, 5a841a7, 20b2846, d96e92c)

[jgibo]

This is ready for review now - not planning on making any further changes before it's reviewed.

[jgibo]

Note: Running the lint fix commands .tox/lint/bin/black . and .tox/lint/bin/isort . applied some lint fixes to other libs (commit cbb3e4d)

[xrmx]

I would drop the commit that fixes linting outside the tornado instrumentation and possibly open a new PR with them.

[jgibo]

I would drop the commit that fixes linting outside the tornado instrumentation and possibly open a new PR with them.

@xrmx Fixed. Reverted original lint fix commit, re-applied on only tornado dir

[lzchen]

@jgibo

Needs a rebase. Please also allow for maintainer editing so we can rebase for you.

[jgibo]

@lzchen I've merged main in and resolved the changelog conflict, is that equivalent to what you meant by rebasing?

It looks like I can't enable maintainer edit as the fork is on a organisation account, not a personal account.

lmk how we should proceed. I'm happy to check it twice daily to keep it up-to-date if it's being prepared for merge.

[jgibo]

Merge conflict resolved, changelog entry moved to Unreleased.Fixed

[lzchen]

It looks like I can't enable maintainer edit as the fork is on a organisation account, not a personal account.

Unfortunately you will have to rebase again. I'll try to address this one asap to merge in before any others.

[jgibo]

@lzchen No worries. Main merged in and changelog confict resolved.

[lzchen]

@jgibo

Seems like we are good for the reviews. Hopefully one more rebase and we should be good to go!

[jgibo]

@lzchen Nice! Rebased.