SignaFX Python Azure Function Wrapper

SignalFx Python Azure Function Wrapper.

Usage

The SignalFx Python Azure Function Wrapper is a wrapper around a decorator used to instrument the execution of the function and send metrics to SignalFx

Installation

Use the github package

pip install git+https://github.com/claranet/signalfx-azure-function-python@vx.x.x#egg=signalfx-azure-function-python

Wrap your function handler

import signalfx_azure_function_python.metrics
import azure.functions as func


@signalfx_azure_function_python.metrics.emit_metrics()
def main(req: func.HttpRequest, context: func.Context) -> func.HttpResponse:
    return func.HttpResponse(
        "Hello World"
    )

• The context parameter is mandatory to retrieve the function name.
• You can pass extra_dimensions in parameters of emit_metrics decorator.

Mandatory environment variables

SIGNALFX_AUTH_TOKEN=xxxxxxx

Optional environment variables

SIGNALFX_SEND_TIMEOUT=milliseconds for signalfx client timeout. Default 1000
SIGNALFX_REALM=EndPoint Realm. Default: us0

Metrics and dimensions sent by the wrapper

The function wrapper sends the following metrics to SignalFx:

Metric Name	Type	Description
azure.function.invocations	Counter	Count number of function invocations
azure.function.errors	Counter	Count number of errors from underlying function handler
azure.function.duration	Gauge	Milliseconds in execution time of underlying function handler

The function wrapper adds the following dimensions to all data points sent to SignalFx:

Dimension	Description
azure_region	Azure region where the function is executed
azure_function_name	Name of the function
azure_resource_name	Name of the function app where the function is running
function_wrapper_version	SignalFx function wrapper qualifier (e.g. signalfx-azurefunction-0.1.0)
is_Azure_Function	Used to differentiate between Azure App Service and Azure Function metrics
metric_source	The literal value of 'azure_function_wrapper'
resource_group	Name of the resource_group who host the function app
subscription_id	Azure subscription ID in which is the function app

Deployment

Add the following in your requirements.txt

git+https://github.com/claranet/signalfx-azure-function-python@vx.x.x#egg=signalfx-azure-function-python

Testing locally

1. Set up the local Azure Function runtime: https://docs.microsoft.com/en-us/azure/azure-functions/functions-run-local

2. Add the environment variables described above to your local.settings.json

3. Wrap function as stated above, run the runtime.

License

Apache Software License v2. Copyright © 2014-2021 Claranet