isabella232 / azure-function-nodejs

SignalFx Azure Functions Node.js wrapper

SignalFx Node Azure Function Wrapper

SignalFx Node Azure Function Wrapper.

Usage

The SignalFx NodeJS Azure Function Wrapper is a wrapper around an Azure Function NodeJS function handler, used to instrument execution of the function and send metrics to SignalFx.

Installation

Use the hosted package:

{
  "name": "my-module",
  "dependencies": {
    "signalfx-azure-functions": "^0.0.10"
  }
}

Wrap your function handler

'use strict';

const signalFxAzureFunction = require('signalfx-azure-functions');

module.exports = signalFxAzureFunction.wrapper((context, some_binding_obj, callback) => {
  context.res = myFunc(context, some_binding_obj);
  callback();
});

• By default, only 1 binding trigger object is passed through the wrapper. If you have multiple, you may need to modify your function to access them through the context object (e.g. context.bindings.myInput).
• The function wrapper will call context.done() in the callback itself.

Configuring the ingest endpoint

By default, this function wrapper will send to the us0 realm. If you are not in this realm you will need to set the SIGNALFX_INGEST_ENDPOINT environment variable to the correct realm ingest endpoint (https://ingest.{REALM}.signalfx.com). To determine what realm you are in, check your profile page in the SignalFx web application (click the avatar in the upper right and click My Profile).

Environment Variables

 SIGNALFX_AUTH_TOKEN=signalfx token

Optional parameters available:

SIGNALFX_SEND_TIMEOUT=milliseconds for signalfx client timeout [1000]

# Change the ingest endpoint URL:
SIGNALFX_INGEST_ENDPOINT=[https://ingest.us0.signalfx.com]

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-0.0.11)
is_Azure_Function	Used to differentiate between Azure App Service and Azure Function metrics
metric_source	The literal value of 'azure_function_wrapper'

Sending a metric from the Azure function

'use strict';

const signalFxAzureFunction = require('signalfx-azure-functions');

module.exports = signalFxAzureFunction.wrapper((context, some_binding_obj, callback) => {
  ....
  signalFxAzureFunction.helper.sendGauge('gauge.name', value);
  callback();
});

Deployment

Run npm pack to package the module with the configuration in package.json.

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 © 2014-2017 SignalFx