Request ASGI attributes passed to Sampler

[tammy-baylis-swi]

Description

This adds HTTP server request attributes to the ASGI instrumentation library's start_span call, making them available to otel sampler's should_sample method. A very basic example:

class MySampler(Sampler):
    def should_sample(
        self,
        parent_context: Optional[OtelContext],
        trace_id: int,
        name: str,
        kind: SpanKind = None,
        attributes: Attributes = None,
        links: Sequence["Link"] = None,
        trace_state: "TraceState" = None,
    ) -> "SamplingResult":
        logger.debug("attributes: %s", attributes)

Before this change, attributes is None. After this change, attributes for an instrumented ASGI app would be:

{'http.scheme': 'http', 'http.host': '172.22.0.2:8005', 'net.host.port': 8005, 'http.flavor': '1.1', 'http.target': '/healthcheck', 'http.url': 'http://172.22.0.2:8005/healthcheck', 'http.method': 'GET', 'http.server_name': '0.0.0.0:8005', 'http.user_agent': 'curl/7.87.0', 'net.peer.ip': '172.22.0.1', 'net.peer.port': 55278, 'http.route': '/healthcheck'}

Fixes #1752

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I have a custom distro that configures the attribute-logging sampler code in the above Description. On my local I run a FastAPI app with opentelemetry-instrument after local install of opentelemetry-instrumentation-asgi==0.39b0.dev and its dependencies. Then I curl the app's /healthcheck route to see stdout logs of the attributes.

Does This PR Require a Core Repo Change?

• Yes. - Link to PR:
• 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: tammy-baylis-swi / name: Tammy Baylis (d17ca4c, 31298d1)

[shalevr]

Could you update the tests? The attributes are changed so the expected attributes in tests should be updated too

[tammy-baylis-swi]

Could you update the tests? The attributes are changed so the expected attributes in tests should be updated too

Hi @shalevr, the final span attributes are the same before and after the code update. The tests in test_asgi_custom_headers.py and test_asgi_middleware.py check the attributes by using get_finished_spans from the TestBase's InMemorySpanExporter, and the tests pass. The code update changes the timing of attribute assignment.

[tammy-baylis-swi]

I've added 7d91b86 to fix a failed test in the aiohttp-client instrumentation library:

test_aiohttp_client_integration.py:118: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
		test_aiohttp_client_integration.py:63: in assert_spans 
 self.assertEqual( 
E AssertionError: Lists differ: [('HT[93 chars]45305/test-path#foobar', 'http.status_code': 200})] != [('HT[93 chars]45305/test-path?query=param#foobar', 'http.status_code': 200})] 
E 
E First differing element 0: 
E ('HTT[91 chars]:45305/test-path#foobar', 'http.status_code': 200}) 
E ('HTT[91 chars]:45305/test-path?query=param#foobar', 'http.status_code': 200}) 
E 
E [('HTTP GET', 
E (<StatusCode.UNSET: 0>, None), 
E {'http.method': 'GET', 
E 'http.status_code': 200, 
E - 'http.url': ' http://127.0.0.1:45305/test-path#foobar'})] 
E + 'http.url': ' http://127.0.0.1:45305/test-path?query=param#foobar'})] 
E ? ++++++++++++

This seems to have fixed the instrumentation tests for py37,8,9,10 and pypy3 on Ubuntu 20.04, while the py311 test last failed with a connection timeout. Is this a known and/or transient issue?:

py311-test-opentelemetry-instrumentation run-test-pre: commands[3] | pip install 'opentelemetry-sdk[test] @ git+https://github.com/open-telemetry/opentelemetry-python.git@2387b4465d930b020df79692a8097e1d54b66ec1#egg=opentelemetry-sdk&subdirectory=opentelemetry-sdk'
Collecting opentelemetry-sdk[test]@ git+https://github.com/open-telemetry/opentelemetry-python.git@2387b4465d930b020df79692a8097e1d54b66ec1#egg=opentelemetry-sdk&subdirectory=opentelemetry-sdk
  Cloning https://github.com/open-telemetry/opentelemetry-python.git (to revision 2387b4465d930b020df79692a8097e1d54b66ec1) to /tmp/pip-install-0tijk4_h/opentelemetry-sdk_d056d10a8af0445582060f9b44fffedd
  Running command git clone --filter=blob:none --quiet https://github.com/open-telemetry/opentelemetry-python.git /tmp/pip-install-0tijk4_h/opentelemetry-sdk_d056d10a8af0445582060f9b44fffedd
  fatal: unable to access 'https://github.com/open-telemetry/opentelemetry-python.git/': Failed to connect to github.com port 443: Connection timed out
  fatal: could not fetch f5236d7c1bc1a9b9598b62fd4d4079e39b695540 from promisor remote
  warning: Clone succeeded, but checkout failed.

  ERROR: py311-test-opentelemetry-instrumentation: commands failed

[cheempz]

@srikanthccv @shalevr any chance we can get this merged in soon?