s3-upload-file-stack.ts

import { aws_apigateway, aws_lambda, aws_lambda_nodejs, aws_s3, Duration, Stack, StackProps } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as path from 'path';

export class S3UploadFileStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);

    const bucket = new aws_s3.Bucket(this, 'Bucket', {});

    const signedUrlLambda = new aws_lambda_nodejs.NodejsFunction(this, 'SignedUrlLambda', {
      runtime: aws_lambda.Runtime.NODEJS_14_X,
      handler: 'handler',
      entry: path.join(__dirname, '..', 'lambdas', 'signed-url', 'index.ts'),
      timeout: Duration.seconds(10),
      environment: {
        BUCKET: bucket.bucketName,
      },
      bundling: {
        sourceMap: false,
        minify: false,
        target: 'es2020',
        externalModules: ['aws-sdk'],
      },
    });

    bucket.grantWrite(signedUrlLambda);

    // Proxy API Gateway
    const api = new aws_apigateway.LambdaRestApi(this, 'ProxyApiGateway', {
      handler: signedUrlLambda,
      restApiName: 'example-s3-upload',
      apiKeySourceType: aws_apigateway.ApiKeySourceType.HEADER,
      defaultMethodOptions: {
        apiKeyRequired: true,
      },
    });
    const apiKey = api.addApiKey('example-signed-url-api-key');
    const usagePlan = api.addUsagePlan('example-s3-upload');
    usagePlan.addApiKey(apiKey);
    usagePlan.addApiStage({ stage: api.deploymentStage });
  }
}