Datadog CDK Construct

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Use this Datadog CDK Construct Library to deploy serverless applications using AWS CDK .

This CDK library automatically configures ingestion of metrics, traces, and logs from your serverless applications by:

  • Installing and configuring the Datadog Lambda library for your Python and Node.js Lambda functions.
  • Enabling the collection of traces and custom metrics from your Lambda functions.
  • Managing subscriptions from the Datadog Forwarder to your Lambda and non-Lambda log groups.

AWS CDK v1 vs AWS CDK v2

Two separate versions of Datadog CDK Constructs exist; datadog-cdk-constructs and datadog-cdk-constructs-v2. These are designed to work with AWS CDK v1 and AWS CDK v2 respectively.

  • datadog-cdk-constructs-v2 requires Node 14+, while datadog-cdk-constructs-v1 supports Node 12+.
  • Otherwise, the use of the two packages is identical.

npm Package Installation:

For use with AWS CDK v2:

yarn add --dev datadog-cdk-constructs-v2
# or
npm install datadog-cdk-constructs-v2 --save-dev

For use with AWS CDK v1:

yarn add --dev datadog-cdk-constructs
# or
npm install datadog-cdk-constructs --save-dev

PyPI Package Installation:

For use with AWS CDK v2:

pip install datadog-cdk-constructs-v2

For use with AWS CDK v1:

pip install datadog-cdk-constructs

Note:

Pay attention to the output from your package manager as the Datadog CDK Construct Library has peer dependencies.

Usage

AWS CDK

  • If you are new to AWS CDK then check out this workshop.
  • The following examples assume the use of AWS CDK v2. If you’re using CDK v1, import datadog-cdk-constructs rather than datadog-cdk-constructs-v2.

Add this to your CDK stack:

import { Datadog } from "datadog-cdk-constructs-v2";

const datadog = new Datadog(this, "Datadog", {
  nodeLayerVersion: <LAYER_VERSION>,
  pythonLayerVersion: <LAYER_VERSION>,
  addLayers: <BOOLEAN>,
  extensionLayerVersion: "<EXTENSION_VERSION>",
  forwarderArn: "<FORWARDER_ARN>",
  flushMetricsToLogs: <BOOLEAN>,
  site: "<SITE>",
  apiKey: "{Datadog_API_Key}",
  apiKeySecretArn: "{Secret_ARN_Datadog_API_Key}",
  apiKmsKey: "{Encrypted_Datadog_API_Key}",
  enableDatadogTracing: <BOOLEAN>,
  enableDatadogLogs: <BOOLEAN>,
  injectLogContext: <BOOLEAN>,
  logLevel: <STRING>,
  env: <STRING>, //Optional
  service: <STRING>, //Optional
  version: <STRING>, //Optional
  tags: <STRING>, //Optional
});
datadog.addLambdaFunctions([<LAMBDA_FUNCTIONS>])
datadog.addForwarderToNonLambdaLogGroups([<LOG_GROUPS>])

Optionally, if you’d like to enable source code integration (Typescript only), you’ll need to make a few changes to your stack setup since the AWS CDK does not support async functions.

Change your initialization function as follows (note: we’re changing this to pass the gitHash value to the CDK):

async function main() {
  // Make sure to add @datadog/datadog-ci via your package manager
  const datadogCi = require("@datadog/datadog-ci");
  const [, gitHash] = await datadogCi.gitMetadata.uploadGitCommitHash('{Datadog_API_Key}', '<SITE>')

  const app = new cdk.App();
  // Pass in the hash to the ExampleStack constructor
  new ExampleStack(app, "ExampleStack", {}, gitHash);
}

In your stack constructor, change to add an optional gitHash parameter, and call addGitCommitMetadata():

export class ExampleStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string, props?: cdk.StackProps, gitHash?: string) {
    ...
    ...
    datadog.addGitCommitMetadata([<YOUR_FUNCTIONS>], gitHash)
  }
}

Configuration

To further configure your Datadog construct, use the following custom parameters:

Note: The descriptions use the npm package parameters, but they also apply to the PyPI package parameters.

npm package parameterPyPI package parameterDescription
addLayersadd_layersWhether to add the Lambda Layers or expect the user to bring their own. Defaults to true. When true, the Lambda Library version variables are also required. When false, you must include the Datadog Lambda library in your functions’ deployment packages.
pythonLayerVersionpython_layer_versionVersion of the Python Lambda layer to install, such as 21. Required if you are deploying at least one Lambda function written in Python and addLayers is true. Find the latest version number here.
nodeLayerVersionnode_layer_versionVersion of the Node.js Lambda layer to install, such as 29. Required if you are deploying at least one Lambda function written in Node.js and addLayers is true. Find the latest version number from here.
extensionLayerVersionextension_layer_versionVersion of the Datadog Lambda Extension layer to install, such as 5. When extensionLayerVersion is set, apiKey (or if encrypted, apiKMSKey or apiKeySecretArn) needs to be set as well. When enabled, lambda function log groups will not be subscribed by the forwarder. Learn more about the Lambda extension here.
forwarderArnforwarder_arnWhen set, the plugin will automatically subscribe the Datadog Forwarder to the functions’ log groups. Do not set forwarderArn when extensionLayerVersion is set.
flushMetricsToLogsflush_metrics_to_logsSend custom metrics using CloudWatch logs with the Datadog Forwarder Lambda function (recommended). Defaults to true . If you disable this parameter, it’s required to set apiKey (or if encrypted, apiKMSKey or apiKeySecretArn).
sitesiteSet which Datadog site to send data. This is only used when flushMetricsToLogs is false or extensionLayerVersion is set. Possible values are datadoghq.com, datadoghq.eu, us3.datadoghq.com, us5.datadoghq.com, and ddog-gov.com. The default is datadoghq.com.
apiKeyapi_keyDatadog API Key, only needed when flushMetricsToLogs is false or extensionLayerVersion is set. For more information about getting a Datadog API key, see the API key documentation.
apiKeySecretArnapi_key_secret_arnThe ARN of the secret storing the Datadog API key in AWS Secrets Manager. Use this parameter in place of apiKey when flushMetricsToLogs is false or extensionLayer is set. Remember to add the secretsmanager:GetSecretValue permission to the Lambda execution role.
apiKmsKeyapi_kms_keyDatadog API Key encrypted using KMS. Use this parameter in place of apiKey when flushMetricsToLogs is false or extensionLayerVersion is set, and you are using KMS encryption.
enableDatadogTracingenable_datadog_tracingEnable Datadog tracing on your Lambda functions. Defaults to true.
enableDatadogLogsenable_datadog_logsSend Lambda function logs to Datadog via the Datadog Lambda Extension. Defaults to true. Note: This setting has no effect on logs sent via the Datadog Forwarder.
injectLogContextinject_log_contextWhen set, the Lambda layer will automatically patch console.log with Datadog’s tracing ids. Defaults to true.
logLevellog_levelWhen set to debug, the Datadog Lambda Library and Extension will log additional information to help troubleshoot issues.
envenvWhen set along with extensionLayerVersion, a DD_ENV environment variable is added to all Lambda functions with the provided value. When set along with forwarderArn, an env tag is added to all Lambda functions with the provided value.
serviceserviceWhen set along with extensionLayerVersion, a DD_SERVICE environment variable is added to all Lambda functions with the provided value. When set along with forwarderArn, a service tag is added to all Lambda functions with the provided value.
versionversionWhen set along with extensionLayerVersion, a DD_VERSION environment variable is added to all Lambda functions with the provided value. When set along with forwarderArn, a version tag is added to all Lambda functions with the provided value.
tagstagsA comma separated list of key:value pairs as a single string. When set along with extensionLayerVersion, a DD_TAGS environment variable is added to all Lambda functions with the provided value. When set along with forwarderArn, the cdk parses the string and sets each key:value pair as a tag to all Lambda functions.

Note: env, service, version, and tags override function level DD_XXX environment variables.

Tracing

Enable X-Ray Tracing on your Lambda functions. For more information, see CDK documentation.

import * as lambda from "aws-cdk-lib/aws-lambda";

const lambda_function = new lambda.Function(this, "HelloHandler", {
  runtime: lambda.Runtime.NODEJS_14_X,
  code: lambda.Code.fromAsset("lambda"),
  handler: "hello.handler",
  tracing: lambda.Tracing.ACTIVE,
});

Nested Stacks

Add the Datadog CDK Construct to each stack you wish to instrument with Datadog. In the example below, we initialize the Datadog CDK Construct and call addLambdaFunctions() in both the RootStack and NestedStack.

import { Datadog } from "datadog-cdk-constructs-v2";
import * as cdk from "aws-cdk-lib";
import { Construct } from "constructs";

class RootStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string, props?: cdk.StackProps) {
    super(scope, id, props);
    new NestedStack(this, "NestedStack");

    const datadog = new Datadog(this, "Datadog", {
      nodeLayerVersion: <LAYER_VERSION>,
      pythonLayerVersion: <LAYER_VERSION>,
      addLayers: <BOOLEAN>,
      forwarderArn: "<FORWARDER_ARN>",
      flushMetricsToLogs: <BOOLEAN>,
      site: "<SITE>",
      apiKey: "{Datadog_API_Key}",
      apiKeySecretArn: "{Secret_ARN_Datadog_API_Key}",
      apiKmsKey: "{Encrypted_Datadog_API_Key}",
      enableDatadogTracing: <BOOLEAN>,
      enableDatadogLogs: <BOOLEAN>,
      injectLogContext: <BOOLEAN>
    });
    datadog.addLambdaFunctions([<LAMBDA_FUNCTIONS>]);

  }
}

class NestedStack extends cdk.NestedStack {
  constructor(scope: Construct, id: string, props?: cdk.NestedStackProps) {
    super(scope, id, props);

    const datadog = new Datadog(this, "Datadog", {
      nodeLayerVersion: <LAYER_VERSION>,
      pythonLayerVersion: <LAYER_VERSION>,
      addLayers: <BOOLEAN>,
      forwarderArn: "<FORWARDER_ARN>",
      flushMetricsToLogs: <BOOLEAN>,
      site: "<SITE>",
      apiKey: "{Datadog_API_Key}",
      apiKeySecretArn: "{Secret_ARN_Datadog_API_Key}",
      apiKmsKey: "{Encrypted_Datadog_API_Key}",
      enableDatadogTracing: <BOOLEAN>,
      enableDatadogLogs: <BOOLEAN>,
      injectLogContext: <BOOLEAN>
    });
    datadog.addLambdaFunctions([<LAMBDA_FUNCTIONS>]);

  }
}

Tags

Add tags to your constructs. We recommend setting an env and service tag to tie Datadog telemetry together. For more information see official AWS documentation and CDK documentation.

How it works

The Datadog CDK construct takes in a list of lambda functions and installs the Datadog Lambda Library by attaching the Lambda Layers for Node.js and Python to your functions. It redirects to a replacement handler that initializes the Lambda Library without any required code changes. Additional configurations added to the Datadog CDK construct will also translate into their respective environment variables under each lambda function (if applicable / required).

While Lambda function based log groups are handled by the addLambdaFunctions method automatically, the construct has an additional function addForwarderToNonLambdaLogGroups which subscribes the forwarder to any additional log groups of your choosing.

Resources to learn about CDK

Repository Structure

In this repository, the folders v1 and v2 correspond to the packages datadog-cdk-constructs and datadog-cdk-contructs-v2. Each can be treated as a separate project (they are separate projen projects with separate dependencies, config files, tests, and scripts).

Additionally, there is a common folder that contains shared logic common to both v1 and v2 packages. This is done by soft-linking a common folder within v1/src and v2/src to the common folder in the root of the repository.

Using Projen

The v1 and v2 Datadog CDK Construct Libraries both use Projen to maintain project configuration files such as the package.json, .gitignore, .npmignore, etc. Most of the configuration files will be protected by Projen via read-only permissions. In order to change these files, edit the .projenrc.js file within v1 or v2 folders, then run npx projen (while in v1 or v2) to synthesize the new changes. Check out Projen for more details.

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 CDK Construct 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.

Testing

If you contribute to this package you can run the tests using yarn test within the v1 or v2 folders. This package also includes a sample application for manual testing:

  1. Open a seperate terminal and cd into v1 or v2.
  2. Run yarn watch, this will ensure the Typescript files in the src directory are compiled to Javascript in the lib directory.
  3. Navigate to src/sample, here you can edit index.ts to test your contributions manually.
  4. At the root of the v1 or v2 directory (whichever you are working on), run npx cdk --app lib/sample/index.js <CDK Command>, replacing <CDK Command> with common CDK commands like synth, diff, or deploy.
  • Note, if you receive “… is not authorized to perform: …” you may also need to authorize the commands with your AWS credentials.

Debug Logs

To display the debug logs for this library, set the DD_CONSTRUCT_DEBUG_LOGS env var to true when running cdk synth (use --quiet to suppress generated template output).

Example: Ensure you are at the root of the v1 or v2 directory

DD_CONSTRUCT_DEBUG_LOGS=true npx cdk --app lib/sample/index.js synth --quiet

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 2021 Datadog, Inc.