OpenTelemetry ASGI Instrumentation

This library provides a ASGI middleware that can be used on any ASGI framework (such as Django, Starlette, FastAPI or Quart) to track requests timing through OpenTelemetry.

Installation

pip install opentelemetry-instrumentation-asgi

Usage (Quart)

from quart import Quart
from opentelemetry.instrumentation.asgi import OpenTelemetryMiddleware

app = Quart(__name__)
app.asgi_app = OpenTelemetryMiddleware(app.asgi_app)

@app.route("/")
async def hello():
    return "Hello!"

if __name__ == "__main__":
    app.run(debug=True)

Usage (Django 3.0)

Modify the application’s asgi.py file as shown below.

import os
from django.core.asgi import get_asgi_application
from opentelemetry.instrumentation.asgi import OpenTelemetryMiddleware

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'asgi_example.settings')

application = get_asgi_application()
application = OpenTelemetryMiddleware(application)

Usage (Raw ASGI)

from opentelemetry.instrumentation.asgi import OpenTelemetryMiddleware

app = ...  # An ASGI application.
app = OpenTelemetryMiddleware(app)

References

• OpenTelemetry Project

API

The opentelemetry-instrumentation-asgi package provides an ASGI middleware that can be used on any ASGI framework (such as Django-channels / Quart) to track requests timing through OpenTelemetry.

class opentelemetry.instrumentation.asgi.CarrierGetter

Bases: opentelemetry.trace.propagation.textmap.DictGetter

get(carrier, key)

Getter implementation to retrieve a HTTP header value from the ASGI scope.

Parameters

• carrier (dict) – ASGI scope object

• key (str) – header name in scope

Return type

List[str]

Returns

A list with a single string with the header value if it exists,

else an empty list.

opentelemetry.instrumentation.asgi.collect_request_attributes(scope)

Collects HTTP request attributes from the ASGI scope and returns a dictionary to be used as span creation attributes.

opentelemetry.instrumentation.asgi.set_status_code(span, status_code)

Adds HTTP response attributes to span using the status_code argument.

opentelemetry.instrumentation.asgi.get_default_span_details(scope)

Default implementation for span_details_callback

Parameters

scope (dict) – the asgi scope dictionary

Return type

Tuple[str, dict]

Returns

a tuple of the span, and any attributes to attach to the span.

class opentelemetry.instrumentation.asgi.OpenTelemetryMiddleware(app, span_details_callback=None)

Bases: object

The ASGI application middleware.

This class is an ASGI middleware that starts and annotates spans for any requests it is invoked with.

Parameters

• app – The ASGI application callable to forward requests to.

• span_details_callback – Callback which should return a string and a tuple, representing the desired span name and a dictionary with any additional span attributes to set. Optional: Defaults to get_default_span_details.