aws-lambda-sns

Reference Documentation:

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

Language	Package
Python	aws_solutions_constructs.aws_lambda_sns
Typescript	@aws-solutions-constructs/aws-lambda-sns
Java	software.amazon.awsconstructs.services.lambdasns

Overview

This AWS Solutions Construct implements an AWS Lambda function connected to an Amazon SNS topic.

Here is a minimal deployable pattern definition:

Typescript

import { Construct } from 'constructs';
import { Stack, StackProps } from 'aws-cdk-lib';
import { LambdaToSns, LambdaToSnsProps } from "@aws-solutions-constructs/aws-lambda-sns";
import * as lambda from 'aws-cdk-lib/aws-lambda';

new LambdaToSns(this, 'test-lambda-sns', {
  lambdaFunctionProps: {
    runtime: lambda.Runtime.NODEJS_20_X,
    handler: 'index.handler',
    code: lambda.Code.fromAsset(`lambda`)
  }
});

Python

from aws_solutions_constructs.aws_lambda_sns import LambdaToSns
from aws_cdk import (
    aws_lambda as _lambda,
    Stack
)
from constructs import Construct

LambdaToSns(
    self, 'test-lambda-sns-stack',
    lambda_function_props=_lambda.FunctionProps(
        code=_lambda.Code.from_asset('lambda'),
        runtime=_lambda.Runtime.PYTHON_3_11,
        handler='index.handler'
    )
)

Java

import software.constructs.Construct;

import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;
import software.amazon.awscdk.services.lambda.*;
import software.amazon.awscdk.services.lambda.Runtime;
import software.amazon.awsconstructs.services.lambdasns.*;

new LambdaToSns(this, "test-lambda-sns-stack", new LambdaToSnsProps.Builder()
        .lambdaFunctionProps(new FunctionProps.Builder()
                .runtime(Runtime.NODEJS_20_X)
                .code(Code.fromAsset("lambda"))
                .handler("index.handler")
                .build())
        .build());

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.
existingTopicObj?	sns.Topic	Existing instance of SNS Topic object, providing both this and topicProps will cause an error.
topicProps?	sns.TopicProps	Optional user provided properties to override the default properties for the SNS topic.
existingVpc?	ec2.IVpc	An optional, existing VPC into which this pattern should be deployed. When deployed in a VPC, the Lambda function will use ENIs in the VPC to access network resources and an Interface Endpoint will be created in the VPC for Amazon SNS. If an existing VPC is provided, the deployVpc property cannot be true. This uses ec2.IVpc to allow clients to supply VPCs that exist outside the stack using the ec2.Vpc.fromLookup() method.
vpcProps?	ec2.VpcProps	Optional user-provided properties to override the default properties for the new VPC. enableDnsHostnames, enableDnsSupport, natGateways and subnetConfiguration are set by the pattern, so any values for those properties supplied here will be overridden. If deployVpc is not true then this property will be ignored.
deployVpc?	boolean	Whether to create a new VPC based on vpcProps into which to deploy this pattern. Setting this to true will deploy the minimal, most private VPC to run the pattern:
topicArnEnvironmentVariableName?	string	Optional Name for the Lambda function environment variable set to the arn of the topic. Default: SNS_TOPIC_ARN
topicNameEnvironmentVariableName?	string	Optional Name for the Lambda function environment variable set to the name of the topic. Default: SNS_TOPIC_NAME
enableEncryptionWithCustomerManagedKey?	boolean	If no key is provided, this flag determines whether the SNS Topic is encrypted with a new CMK or an AWS managed key. This flag is ignored if any of the following are defined: topicProps.masterKey, encryptionKey or encryptionKeyProps.
encryptionKey?	kms.Key	An optional, imported encryption key to encrypt the SNS Topic with.
encryptionKeyProps?	kms.KeyProps	Optional user provided properties to override the default properties for the KMS encryption key used to encrypt the SNS Topic with.

Pattern Properties

Name	Type	Description
lambdaFunction	lambda.Function	Returns an instance of the Lambda function created by the pattern.
snsTopic	sns.Topic	Returns an instance of the SNS topic created by the pattern.
vpc?	ec2.IVpc	Returns an interface on the VPC used by the pattern (if any). This may be a VPC created by the pattern or the VPC supplied to the pattern constructor.

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 to access the Firehose Delivery Stream

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

• Enable X-Ray Tracing

• Set Environment Variables

  • (default) SNS_TOPIC_NAME

  • (default) SNS_TOPIC_ARN

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

Amazon SNS Topic

• Configure least privilege access permissions for SNS Topic

• Enable server-side encryption forSNS Topic using AWS managed KMS Key

• Enforce encryption of data in transit

Architecture

Github

Go to the Github repo for this pattern to view the code, read/create issues and pull requests and more.