aws-lambda-step-function module

Some of our early constructs don’t meet the naming standards that evolved for the library. We are releasing completely feature compatible versions with corrected names. The underlying implementation code is the same regardless of whether you deploy the construct using the old or new name. We will support both names for all 1.x releases, but in 2.x we will only publish the correctly named constructs.

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 This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

Reference Documentation:	https://docs.aws.amazon.com/solutions/latest/constructs/

Language	Package
Python	`aws_solutions_constructs.aws_lambda_step_function`
Typescript	`@aws-solutions-constructs/aws-lambda-step-function`
Java	`software.amazon.awsconstructs.services.lambdastepfunction`

This AWS Solutions Construct implements an AWS Lambda function connected to an AWS Step Function.

Here is a minimal deployable pattern definition in Typescript:

import { LambdaToStepFunction } from '@aws-solutions-constructs/aws-lambda-step-function';
import * as stepfunctions from '@aws-cdk/aws-stepfunctions';

const startState = new stepfunctions.Pass(stack, 'StartState');

new LambdaToStepFunction(this, 'LambdaToStepFunctionPattern', {
    lambdaFunctionProps: {
        runtime: lambda.Runtime.NODEJS_12_X,
        handler: 'index.handler',
        code: lambda.Code.fromAsset(`${__dirname}/lambda`)
    },
    stateMachineProps: {
      definition: startState
    }
});

Initializer

new LambdaToStepFunction(scope: Construct, id: string, props: LambdaToStepFunctionProps);

Parameters

scope Construct
id string
props LambdaToStepFunctionProps

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`	User provided props to override the default props for the Lambda function.
stateMachineProps	`sfn.StateMachineProps`	User provided props for the sfn.StateMachine.
createCloudWatchAlarms	`boolean`	Whether to create recommended CloudWatch alarms
logGroupProps?	`logs.LogGroupProps`	User provided props to override the default props for for the CloudWatchLogs LogGroup.
stateMachineEnvironmentVariableName?	`string`	Optional Name for the Step Functions state machine environment variable set for the producer Lambda function.

Pattern Properties

Name	Type	Description
lambdaFunction	`lambda.Function`	Returns an instance of the Lambda function created by the pattern.
stateMachine	`sfn.StateMachine`	Returns an instance of StateMachine created by the construct.
stateMachineLogGroup	`logs.ILogGroup`	Returns an instance of the ILogGroup created by the construct for StateMachine
cloudwatchAlarms?	`cloudwatch.Alarm[]`	Returns a list of alarms created by the construct.

Default settings

Out of the box implementation of the Construct without any override will set the following defaults:

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
Set Environment Variables
- (default) STATE_MACHINE_ARN
- AWS_NODEJS_CONNECTION_REUSE_ENABLED (for Node 10.x and higher functions)

AWS Step Function

Enable CloudWatch logging for API Gateway
Deploy best practices CloudWatch Alarms for the Step Function

Architecture

Architecture Diagram