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.

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://pops.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