Azure Function OpenTelemetry instrumentation of FastAPI

[claria]

• Package Name: azure-monitor-opentelemetry
• Package Version:
• Operating System: Windows/Linux
• Python Version: 3.11.9

Describe the bug

I am testing to use opentelemetry for a fastapi app running in azure function. I use the auto instrumentation of fastapi given by the package opentelemetry-instrumentation-fastapi.

While it is working and all logs and spans are exported to Azure AppInsights, the specific entry in the requests table is created in an unfortunate way.

I have one route "/hello/{name}". As you can see from the spans created from opentelemetry the spans get the name "GET /hello/{name}" while the entry in the requests table gets the name "GET /hello/1" (with the actual url). This destroys the grouping in appInsights as can bee seen in the screenshots:

To Reproduce

function_app.py

import logging

import azure.functions as func
import fastapi
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor

fastapi_app = fastapi.FastAPI()

FastAPIInstrumentor.instrument_app(fastapi_app)

logger = logging.getLogger(__name__)


@fastapi_app.get("/hello/{name}")
async def get_name(name: str):
    logger.info(f"Hello {name}")
    return {
        "name": name,
    }


app = func.AsgiFunctionApp(app=fastapi_app,
                           http_auth_level=func.AuthLevel.ANONYMOUS,
                           function_name='fastapi')
import logging

import azure.functions as func
import fastapi
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor

fastapi_app = fastapi.FastAPI()

FastAPIInstrumentor.instrument_app(fastapi_app)

logger = logging.getLogger(__name__)


@fastapi_app.get("/hello/{name}")
async def get_name(name: str):
    logger.info(f"Hello {name}")
    return {
        "name": name,
    }


app = func.AsgiFunctionApp(app=fastapi_app,
                           http_auth_level=func.AuthLevel.ANONYMOUS,
                           function_name='fastapi')

host.json:

{
  "version": "2.0",
  "extensions": {
    "http": {
      "routePrefix": ""
    }
  },
  "telemetryMode": "OpenTelemetry"
}

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "PYTHON_ENABLE_INIT_INDEXING": "1",
    "PYTHON_ENABLE_OPENTELEMETRY": true,
    "PYTHON_APPLICATIONINSIGHTS_ENABLE_TELEMETRY": true,
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "AzureWebJobsStorage": "XXXXXXXXXXXXXXXXXXXXXX",
    "APPLICATIONINSIGHTS_CONNECTION_STRING": "XXXXXXXXXXXXXXXXXXXXXXX"
  }
}

requirements.txt:

azure-functions==1.24.0b3
fastapi==0.116.1
azure-monitor-opentelemetry==1.6.13
opentelemetry-instrumentation-fastapi==0.57.b0

Expected behavior
Use the route name (with route param template) or the actual endpoint (function) name.

Screenshots

Additional context
Add any other context about the problem here.

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @gulopesd @Haiying-MSFT @jairmyree @joshfree @KarishmaGhiya @KevinBlasko @kurtzeborn @pvaneck @scottaddie @srnagar @ToddKingMSFT.

[claria]

Hi, is there any feedback to this issue?

I tested a bit and found out the following:

• the entries in the requests table in appinsights are populated by server type spans in opentelemetry

• Fastapi opentelemetry integration (correctly) does not produce a server type span as we have an external correlation context.

• The current entries in the requests table are not produced by the python azure function worker but already sometime before (in the c# worker?)

• I could not find a configuration setting to disable the logging for these entries (like setting Host.Results logging to error)

The only way i found to correctly show the routes as separates operations i had to do the following.

• break the correlation context by calling configure_azure_monitor(...) from within the app and not setting "telemetryMode": "OpenTelemetry" in host.results and disabling the duplicated logs within host.json logging configuration

But of course this brings again more downsides than advantages. In my opinion, there should be a possibility to set the span/requests name from within the application itself.

[claria]

@hectorhdzg Any recommendation what to do here?

[rads-1996]

@claria Thanks for reaching out! I’ve tested using the same environment and code you provided, and I’m seeing the grouping behave as expected. I’ve set telemetryMode to OpenTelemetry in host.json, and everything works correctly on my end. For reference, I’m using azure-monitor-opentelemetry==1.8.1 and opentelemetry-instrumentation-fastapi==0.58b0.