Request/Response hooks

The urllib instrumentation supports extending tracing behavior with the help of request and response hooks. These are functions that are called back by the instrumentation right after a Span is created for a request and right before the span is finished processing a response respectively. The hooks can be configured as follows:

from opentelemetry.instrumentation.urllib import URLLibInstrumentor

# `request_obj` is an instance of urllib.request.Request
def request_hook(span, request_obj):
    pass

# `request_obj` is an instance of urllib.request.Request
# `response` is an instance of http.client.HTTPResponse
def response_hook(span, request_obj, response):
    pass

URLLibInstrumentor().instrument(
    request_hook=request_hook, response_hook=response_hook
)

Exclude lists

To exclude certain URLs from being tracked, set the environment variable OTEL_PYTHON_URLLIB_EXCLUDED_URLS (or OTEL_PYTHON_EXCLUDED_URLS as fallback) with comma delimited regexes representing which URLs to exclude.

For example,

export OTEL_PYTHON_URLLIB_EXCLUDED_URLS="client/.*/info,healthcheck"

will exclude requests such as https://site/client/123/info and https://site/xyz/healthcheck.