datadog-lambda-js

What is datadog-lambda-js?

The datadog-lambda-js npm package is designed to help you monitor and trace your AWS Lambda functions with Datadog. It provides tools to automatically collect and send metrics, logs, and traces from your Lambda functions to Datadog, enabling you to gain insights into the performance and behavior of your serverless applications.

What are datadog-lambda-js's main functionalities?

Automatic Tracing

This feature allows you to automatically trace your Lambda function executions. By wrapping your handler with the `datadog` function, you can send traces to Datadog without manually instrumenting your code.

const { datadog } = require('datadog-lambda-js');

const handler = datadog(async (event, context) => {
  // Your Lambda function code here
  return { statusCode: 200, body: 'Hello, world!' };
});

module.exports.handler = handler;

Custom Metrics

This feature allows you to send custom metrics from your Lambda functions to Datadog. You can use the `sendDistributionMetric` function to send metrics with specific values and tags.

const { sendDistributionMetric } = require('datadog-lambda-js');

const handler = async (event, context) => {
  // Your Lambda function code here
  sendDistributionMetric('my_custom_metric', 42, 'tag:value');
  return { statusCode: 200, body: 'Hello, world!' };
};

module.exports.handler = handler;

Log Forwarding

This feature enables you to forward logs from your Lambda functions to Datadog. By wrapping your handler with the `datadog` function, logs generated within your Lambda function will be automatically sent to Datadog.

const { datadog } = require('datadog-lambda-js');

const handler = datadog(async (event, context) => {
  console.log('This is a log message');
  return { statusCode: 200, body: 'Hello, world!' };
});

module.exports.handler = handler;

Other packages similar to datadog-lambda-js

aws-xray-sdk

The aws-xray-sdk package is an AWS service that provides tracing capabilities for AWS Lambda functions. It allows you to trace requests as they travel through your entire application, including Lambda functions, and visualize the trace data in the AWS X-Ray console. While it offers tracing similar to datadog-lambda-js, it is specific to the AWS ecosystem and does not provide the same level of integration with Datadog.

serverless-plugin-datadog

The serverless-plugin-datadog package is a Serverless Framework plugin that automatically instruments your Lambda functions with Datadog. It provides similar functionality to datadog-lambda-js but is designed to work within the Serverless Framework, making it easier to integrate Datadog monitoring into your serverless applications.

README

datadog-lambda-js

Datadog Lambda Library for Node.js (18.x, 20.x, and 22.x) enables enhanced Lambda metrics, distributed tracing, and custom metric submission from AWS Lambda functions.

Installation

Follow the installation instructions, and view your function's enhanced metrics, traces and logs in Datadog.

Configuration

Follow the configuration instructions to tag your telemetry, capture request/response payloads, filter or scrub sensitive information from logs or traces, and more.

For additional tracing configuration options, check out the official documentation for Datadog trace client.

Besides the environment variables supported by dd-trace-js, the datadog-lambda-js library added following environment variables.

Environment Variables	Description	Default Value
DD_ENCODE_AUTHORIZER_CONTEXT	When set to true for Lambda authorizers, the tracing context will be encoded into the response for propagation. Supported for NodeJS and Python.	true
DD_DECODE_AUTHORIZER_CONTEXT	When set to true for Lambdas that are authorized via Lambda authorizers, it will parse and use the encoded tracing context (if found). Supported for NodeJS and Python.	true
DD_COLD_START_TRACING	When true (default), tracing occurs during cold start which creates many child spans. When false, only one cold start span is created. Used in NodeJS and Python.	true
DD_MIN_COLD_START_DURATION	Sets the minimum duration (in milliseconds) for a module load event to be traced via Cold Start Tracing. Number.	3
DD_COLD_START_TRACE_SKIP_LIB	optionally skip creating Cold Start Spans for a comma-separated list of libraries. Useful to limit depth or skip known libraries.	./opentracing/tracer
DD_CAPTURE_LAMBDA_PAYLOAD	[Captures incoming and outgoing AWS Lambda payloads][1] in the Datadog APM spans for Lambda invocations.	false
DD_CAPTURE_LAMBDA_PAYLOAD_MAX_DEPTH	Determines the level of detail captured from AWS Lambda payloads, which are then assigned as tags for the aws.lambda span. It specifies the nesting depth of the JSON payload structure to process. Once the specified maximum depth is reached, the tag's value is set to the stringified value of any nested elements beyond this level. For example, given the input payload: { "lv1" : { "lv2": { "lv3": "val" } } } If the depth is set to 2, the resulting tag's key is set to function.request.lv1.lv2 and the value is {\"lv3\": \"val\"}. If the depth is set to 0, the resulting tag's key is set to function.request and value is {\"lv1\":{\"lv2\":{\"lv3\": \"val\"}}}	10

Lambda Profiling Beta

Datadog's Continuous Profiler is now available in beta for NodeJS in version 6.87.0 and layer version 87 and above. This optional feature is enabled by setting the DD_PROFILING_ENABLED environment variable to true. During the beta period, profiling is available at no additional cost.

Major Version Notes

5.x.x

The 5.x.x release introduces version 2 of the Datadog tracer, dd-trace-js. This includes a few breaking changes, and the migration guide found here.

The first 5.x.x version was released with Lambda Layer version 69.

6.x.x

The 6.x.x release introduces support for the node 16 runtime and esm modules.

7.x.x

The 7.x.x release drops support for Node12, and upgrades dd-trace-js to version 3.x

8.x.x

The 8.x.x release drops support for Node14, and upgrades dd-trace-js to version 4.x

9.x.x

The 9.x.x release changed how Lambda's traceID is hashed if the incoming payload contains Step Functions context object. This change only affects those who uses inject Step Functions context object into Lambda payload.

There is a full migration guide available here. Some changes are more likely to impact Serverless users:

• HTTP Operation Name Changed. HTTP requests will no longer appear as a separate client under *-http-client, which polluted the APM service catalog.
• tracer.currentSpan() has been deprecated for a long time, and is now removed.
• tracer.bindEmitter() is similarly removed after being deprecated.
• It is no longer possible to bind promises or event emitters with tracer.scope().bind(...)

Opening Issues

If you encounter a bug with this package, we want to hear about it. Before opening a new issue, search the existing issues to avoid duplicates.

When opening an issue, include the Datadog Lambda Layer version, Node version, and stack trace if available. In addition, include the steps to reproduce when appropriate.

You can also open an issue for a feature request.

Contributing

If you find an issue with this package and have a fix, please feel free to open a pull request following the procedures.

Community

For product feedback and questions, join the #serverless channel in the Datadog community on Slack.

License

Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.

This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2019 Datadog, Inc.