Fix Lambda bundling by using NodejsFunction

Author: kaiz-io

typescript/postgres-lambda/lib/postgres-lambda-stack.ts

@@ -6,6 +6,7 @@ import * as lambda from 'aws-cdk-lib/aws-lambda';
 import * as iam from 'aws-cdk-lib/aws-iam';
 import * as cr from 'aws-cdk-lib/custom-resources';
 import * as path from 'path';
+import * as nodejs from 'aws-cdk-lib/aws-lambda-nodejs';
 
 export class PostgresLambdaStack extends cdk.Stack {
   constructor(scope: Construct, id: string, props?: cdk.StackProps) {
@@ -30,11 +31,10 @@ export class PostgresLambdaStack extends cdk.Stack {
       credentials: rds.Credentials.fromGeneratedSecret('postgres'),
     });
 
-    // Create a Lambda function that calls PostgreSQL
-    const lambdaToPostgres = new lambda.Function(this, 'LambdaToPostgres', {
+    // Create a Lambda function that calls PostgreSQL using NodejsFunction
+    const lambdaToPostgres = new nodejs.NodejsFunction(this, 'LambdaToPostgres', {
       runtime: lambda.Runtime.NODEJS_LATEST,
-      handler: 'index.handler',
-      code: lambda.Code.fromAsset(path.join(__dirname, '../lambda/lambda-to-postgres')),
+      entry: path.join(__dirname, '../lambda/lambda-to-postgres/index.js'),
       vpc,
       vpcSubnets: {
         subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS,
@@ -43,6 +43,11 @@ export class PostgresLambdaStack extends cdk.Stack {
         DB_SECRET_ARN: dbCluster.secret?.secretArn || '',
         DB_NAME: 'demodb',
       },
+      bundling: {
+        externalModules: [
+          'aws-sdk', // Use the AWS SDK available in the Lambda runtime
+        ],
+      },
       timeout: cdk.Duration.seconds(30),
     });
 
@@ -52,26 +57,28 @@ export class PostgresLambdaStack extends cdk.Stack {
     // Grant the Lambda function permission to read the database secret
     dbCluster.secret?.grantRead(lambdaToPostgres);
 
-    // Create a Lambda function that is called by PostgreSQL
-    const postgresFunction = new lambda.Function(this, 'PostgresFunction', {
+    // Create a Lambda function that is called by PostgreSQL using NodejsFunction
+    const postgresFunction = new nodejs.NodejsFunction(this, 'PostgresFunction', {
       runtime: lambda.Runtime.NODEJS_LATEST,
-      handler: 'index.handler',
-      code: lambda.Code.fromAsset(path.join(__dirname, '../lambda/postgres-to-lambda')),
+      entry: path.join(__dirname, '../lambda/postgres-to-lambda/index.js'),
       environment: {
         FUNCTION_NAME: 'PostgresFunction',
       },
+      bundling: {
+        externalModules: [
+          'aws-sdk', // Use the AWS SDK available in the Lambda runtime
+        ],
+      },
       timeout: cdk.Duration.seconds(30),
     });
 
-
     // Create a role for PostgreSQL to assume to invoke Lambda
     const postgresLambdaRole = new iam.Role(this, 'PostgresLambdaRole', {
       assumedBy: new iam.ServicePrincipal('rds.amazonaws.com'),
     });
 
     postgresFunction.grantInvoke(postgresLambdaRole);
 
-
     const l1DbCluster = dbCluster.node.defaultChild as rds.CfnDBCluster
     const exisitingProperty = (l1DbCluster.associatedRoles as []) || [];
     console.log(exisitingProperty);
@@ -85,11 +92,10 @@ export class PostgresLambdaStack extends cdk.Stack {
 
     l1DbCluster.addPropertyOverride('AssociatedRoles', updatedRoles);
 
-    // Create Lambda function for PostgreSQL setup
-    const setupFunction = new lambda.Function(this, 'PostgresSetupFunction', {
+    // Create Lambda function for PostgreSQL setup using NodejsFunction
+    const setupFunction = new nodejs.NodejsFunction(this, 'PostgresSetupFunction', {
       runtime: lambda.Runtime.NODEJS_LATEST,
-      handler: 'index.handler',
-      code: lambda.Code.fromAsset(path.join(__dirname, '../lambda/postgres-setup')),
+      entry: path.join(__dirname, '../lambda/postgres-setup/index.js'),
       vpc,
       vpcSubnets: {
         subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS,
@@ -99,6 +105,11 @@ export class PostgresLambdaStack extends cdk.Stack {
         DB_NAME: 'demodb',
         POSTGRES_FUNCTION_NAME: postgresFunction.functionName,
       },
+      bundling: {
+        externalModules: [
+          'aws-sdk', // Use the AWS SDK available in the Lambda runtime
+        ],
+      },
       timeout: cdk.Duration.minutes(5),
     });