wflambda

README

wavefront-lambda-go

A Go wrapper for AWS Lambda so you can monitor everything from your Wavefront dashboard

Installation

Using go get

go get github.com/wavefronthq/wavefront-lambda-go

Basic Usage

To connect your Lambda functions to Wavefront, you'll need to set two environment variables, import this module, and wrap your AWS Lambda handler function with wflambda.Wrapper(handler). The environment variables you'll need to set are:

• WAVEFRONT_URL: The URL of your Wavefront instance (like, https://myinstance.wavefront.com).
• WAVEFRONT_API_TOKEN: Your Wavefront API token (see the docs how to create an API token).

package main

import (
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	wflambda "github.com/wavefronthq/wavefront-lambda-go" // Import this library
)

func handler() (string, error){
	return "Hello World", nil
}

func main() {
	// Wrap the handler with wflambda.Wrapper()
	lambda.Start(wflambda.Wrapper(handler))
}

Standard Point Tags

Point tags are key-value pairs (strings) that are associated with a point. Point tags provide additional context for your data and allow you to fine-tune your queries so the output shows just what you need. The below point tags are sent to Wavefront for each metric.

Point Tag	Description
LambdaArn	ARN (Amazon Resource Name) of the Lambda function.
Region	AWS Region of the Lambda function.
accountId	AWS Account ID from which the Lambda function was invoked.
ExecutedVersion	The version of Lambda function.
FunctionName	The name of Lambda function.
Resource	The name and version/alias of Lambda function. (like DemoLambdaFunc:aliasProd)
EventSourceMappings	AWS Event source mapping Id. (Set in case of Lambda invocation by AWS Poll-Based Services)

Standard Metrics

Based on the environment variable REPORT_STANDARD_METRICS the wrapper will send standard metrics to Wavefront. Set the variable to to false to not send the standard metrics. When the variable is not set, it will use the default value true.

Metric Name	Type	Description
aws.lambda.wf.invocations.count	Delta Counter	Count of number of lambda function invocations aggregated at the server.
aws.lambda.wf.errors.count	Delta Counter	Count of number of errors aggregated at the server.
aws.lambda.wf.coldstarts.count	Delta Counter	Count of number of cold starts aggregated at the server.
aws.lambda.wf.duration.value	Gauge	Execution time of the Lambda handler function in milliseconds.

Custom Metrics

You can send custom business metrics to Wavefront using the go-metrics-wavefront client. The below code reports a counter, a delta counter, and two gauges. All metric names should be unique. If you have metrics that you want to track as both counter and delta counter, you'll have to add a suffix to one of the metrics. Having the same metric name for any two types of metrics will result in only one time series at the server and thus cause collisions.

The code below imported this module and wrapped the handler function argument in main with wflambda.Wrapper(handler). During each execution four metrics are collected and sent to Wavefront with both the standard point tags and the point tags created in the handler.

package main

import (
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/rcrowley/go-metrics"
	wavefront "github.com/wavefronthq/go-metrics-wavefront"
	wflambda "github.com/wavefronthq/wavefront-lambda-go"
)

func handler() {
	// Point Tags
	appTags := map[string]string{
		"key2":   "val1",
		"key1":   "val2",
		"key0":   "val0",
		"key4":   "val4",
		"key3":   "val3",
	}

	// Register Counter with desired tags.
	customRawCounter := metrics.NewCounter()
	wavefront.RegisterMetric("counter", customRawCounter, appTags)
	customRawCounter.Inc(1)

	// Register Delta Counter with desired tags.
	customDeltaCounter := metrics.NewCounter()
	deltaCounterName := wavefront.DeltaCounterName("deltaCounter")
	wavefront.RegisterMetric(deltaCounterName, customDeltaCounter, appTags)
	customDeltaCounter.Inc(1)

	// Register Gauge with desired tags.
	gaugeValue := metrics.NewGauge()
	wavefront.RegisterMetric("gaugeValue", gaugeValue, appTags)
	gaugeValue.Update(551)

	// Register Float Gauge with desired tags.
	gaugeFloatValue := metrics.NewGaugeFloat64()
	wavefront.RegisterMetric("gaugeFloatValue", gaugeFloatValue, appTags)
	gaugeFloatValue.Update(551.4)
}

func main() {
	lambda.Start(wflambda.Wrapper(handler))
}

Documentation

Overview

Package wflambda is a Go wrapper library for AWS Lambda so you can monitor everything from your Wavefront (https://wavefront.com) dashboard. The package includes a set of standard metrics it can send to Wavefront and can be extended to send custom metrics using https://github.com/rcrowley/go-metrics.

The reported standard metrics are

| Metric Name | Type | Description | | --------------------------------- | ------------- | ----------------------------------------------------------------------- | | aws.lambda.wf.invocations.count | Delta Counter | Count of number of lambda function invocations aggregated at the server.| | aws.lambda.wf.errors.count | Delta Counter | Count of number of errors aggregated at the server. | | aws.lambda.wf.coldstarts.count | Delta Counter | Count of number of cold starts aggregated at the server. | | aws.lambda.wf.duration.value | Gauge | Execution time of the Lambda handler function in milliseconds. |

To connect to Wavefront, you'll need to set the WAVEFRONT_URL and WAVEFRONT_API_TOKEN environment variables. To send the above standard metrics, you'll need to set the environment variable REPORT_STANDARD_METRICS to true.

Index

• func Wrapper(lambdaHandler interface{}) interface{}

Functions

func Wrapper

func Wrapper(lambdaHandler interface{}) interface{}

Wrapper returns the Wavefront Lambda wrapper. The wrapper collects the AWS Lambda standard metrics and reports it directly to the specified Wavefront URL. To successfully execute the Lambda function and send metrics to Wavefront, the following environment variables should be set:

* WAVEFRONT_URL: The URL of your Wavefront instance (like https://myinstance.wavefront.com). * WAVEFRONT_API_TOKEN: Your Wavefront API token (see the [docs](https://docs.wavefront.com/wavefront_api.html) how to create an API token). * REPORT_STANDARD_METRICS: Report standard metrics or not (defaults to true).