opentelemetry-instrumentation-flask 0.32b0

Flask instrumentation for OpenTelemetry

This library builds on the OpenTelemetry WSGI middleware to track web requests in Flask applications.

Installation

pip install opentelemetry-instrumentation-flask

Configuration

Exclude lists

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

For example,

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

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

You can also pass the comma delimited regexes to the instrument_app method directly:

FlaskInstrumentor().instrument_app(app, excluded_urls="client/.*/info,healthcheck")

Request/Response hooks

Utilize request/reponse hooks to execute custom logic to be performed before/after performing a request. Environ is an instance of WSGIEnvironment (flask.request.environ). Response_headers is a list of key-value (tuples) representing the response headers returned from the response.

def request_hook(span: Span, environ: WSGIEnvironment):
    if span and span.is_recording():
        span.set_attribute("custom_user_attribute_from_request_hook", "some-value")

def response_hook(span: Span, status: str, response_headers: List):
    if span and span.is_recording():
        span.set_attribute("custom_user_attribute_from_response_hook", "some-value")

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

Flask Request object reference: https://flask.palletsprojects.com/en/2.0.x/api/#flask.Request

References

• OpenTelemetry Flask Instrumentation
• OpenTelemetry Project
• OpenTelemetry Python Examples