aws-dynamodb-stream-lambda

All classes are under active development and subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

Note: To ensure proper functionality, the AWS Solutions Constructs packages and AWS CDK packages in your project must be the same version.

Language	Package
Python	aws_solutions_constructs.aws_dynamodb_stream_lambda
Typescript	@aws-solutions-constructs/aws-dynamodb-stream-lambda
Java	software.amazon.awsconstructs.services.dynamodbstreamlambda

Overview

This AWS Solutions Construct implements a pattern Amazon DynamoDB table with stream to invoke the AWS Lambda function with the least privileged permissions.

Here is a minimal deployable pattern definition:

import { DynamoDBStreamToLambdaProps, DynamoDBStreamToLambda} from '@aws-solutions-constructs/aws-dynamodb-stream-lambda';

new DynamoDBStreamToLambda(this, 'test-dynamodb-stream-lambda', {
    lambdaFunctionProps: {
        runtime: lambda.Runtime.NODEJS_14_X,
        // This assumes a handler function in lib/lambda/index.js
        code: lambda.Code.fromAsset(`${__dirname}/lambda`),
        handler: 'index.handler'
    },
});

Initializer

new DynamoDBStreamToLambda(scope: Construct, id: string, props: DynamoDBStreamToLambdaProps);

Parameters

• scope Construct

• id string

• props DynamoDBStreamToLambdaProps

Pattern Construct Props

Name	Type	Description
existingLambdaObj?	lambda.Function	Existing instance of Lambda Function object, providing both this and lambdaFunctionProps will cause an error.
lambdaFunctionProps?	lambda.FunctionProps	Optional user-provided properties to override the default properties for the Lambda function. Ignored if an existingLambdaObj is provided.
dynamoTableProps?	dynamodb.TableProps	Optional user provided props to override the default props for DynamoDB Table
existingTableInterface?	dynamodb.ITable	Existing instance of DynamoDB table object or interface, providing both this and dynamoTableProps will cause an error.
dynamoEventSourceProps?	aws-lambda-event-sources.DynamoEventSourceProps	Optional user provided props to override the default props for DynamoDB Event Source

Pattern Properties

Name	Type	Description
dynamoTableInterface	dynamodb.ITable	Returns an instance of dynamodb.ITable created by the construct.
dynamoTable?	dynamodb.Table	Returns an instance of dynamodb.Table created by the construct. IMPORTANT: If existingTableInterface was provided in Pattern Construct Props, this property will be undefined.
lambdaFunction	lambda.Function	Returns an instance of the Lambda function created by the pattern.

Lambda function

This pattern requires a Lambda function that can post data into the Elasticsearch service from the DynamoDB stream. A sample function is provided here.

Default settings

Out-of-the-box implementation of this pattern without any overrides will set the following defaults:

Amazon DynamoDB Table

• Set the billing mode for DynamoDB Table to On-Demand (Pay per request)

• Enable server-side encryption for DynamoDB Table using AWS managed KMS Key

• Creates a partition key called 'id' for DynamoDB Table

• Retain the Table when deleting the CloudFormation stack

• Enable continuous backups and point-in-time recovery

AWS Lambda Function

• Configure limited privilege access IAM role for Lambda function

• Enable reusing connections with Keep-Alive for NodeJs Lambda function

• Enable X-Ray tracing

• Enable Failure-Handling features: enable bisect on function Error; set default Maximum Record Age (24 hours); set default Maximum Retry Attempts (500); and deploy SQS dead-letter queue as destination on failure

• Set environment variables:

  • AWS_NODEJS_CONNECTION_REUSE_ENABLED (for Node 10.x and higher functions)

Architecture

GitHub

To view the code for this pattern, create/view issues and pull requests, and more:
	@aws-solutions-constructs/aws-dynamodb-stream-lambda