Optimizacion de AWS Lambda con Claude Code

Acelerar el desarrollo de AWS Lambda con Claude Code

AWS Lambda es un servicio de computacion serverless basado en eventos. Se integra estrechamente con servicios de AWS como API Gateway, S3 y DynamoDB, permitiendo construir backends escalables. Con Claude Code, puedes avanzar eficientemente en los patrones de implementacion propios de Lambda y la escritura de IaC.

Diseno basico de funciones Lambda

> Crea una funcion Lambda en TypeScript.
> Configurada para procesar solicitudes de API Gateway.

// src/handlers/api.ts
import {
  APIGatewayProxyEvent,
  APIGatewayProxyResult,
  Context,
} from 'aws-lambda';

export const handler = async (
  event: APIGatewayProxyEvent,
  context: Context
): Promise<APIGatewayProxyResult> => {
  const { httpMethod, path, body, queryStringParameters } = event;

  try {
    switch (`${httpMethod} ${path}`) {
      case 'GET /users':
        return await getUsers(queryStringParameters);
      case 'POST /users':
        return await createUser(JSON.parse(body || '{}'));
      case 'GET /users/{id}':
        const id = event.pathParameters?.id;
        return await getUser(id!);
      default:
        return response(404, { error: 'Not Found' });
    }
  } catch (error) {
    console.error('Error en Lambda:', error);
    return response(500, { error: 'Internal Server Error' });
  }
};

function response(statusCode: number, body: object): APIGatewayProxyResult {
  return {
    statusCode,
    headers: {
      'Content-Type': 'application/json',
      'Access-Control-Allow-Origin': '*',
    },
    body: JSON.stringify(body),
  };
}

async function getUsers(params: any) {
  // Obtener lista de usuarios de DynamoDB
  return response(200, { users: [] });
}

async function createUser(data: any) {
  return response(201, { id: 'new-user-id', ...data });
}

async function getUser(id: string) {
  return response(200, { id, name: 'User' });
}

Integracion con DynamoDB

> Crea utilidades para operaciones CRUD con DynamoDB.

// src/lib/dynamodb.ts
import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import {
  DynamoDBDocumentClient,
  GetCommand,
  PutCommand,
  QueryCommand,
  DeleteCommand,
} from '@aws-sdk/lib-dynamodb';

const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);

const TABLE_NAME = process.env.TABLE_NAME!;

export async function getItem<T>(pk: string, sk: string): Promise<T | null> {
  const { Item } = await docClient.send(
    new GetCommand({
      TableName: TABLE_NAME,
      Key: { PK: pk, SK: sk },
    })
  );
  return (Item as T) || null;
}

export async function putItem(item: Record<string, any>): Promise<void> {
  await docClient.send(
    new PutCommand({
      TableName: TABLE_NAME,
      Item: {
        ...item,
        createdAt: new Date().toISOString(),
        updatedAt: new Date().toISOString(),
      },
    })
  );
}

export async function queryItems<T>(
  pk: string,
  skPrefix?: string
): Promise<T[]> {
  const params: any = {
    TableName: TABLE_NAME,
    KeyConditionExpression: skPrefix
      ? 'PK = :pk AND begins_with(SK, :sk)'
      : 'PK = :pk',
    ExpressionAttributeValues: { ':pk': pk },
  };

  if (skPrefix) {
    params.ExpressionAttributeValues[':sk'] = skPrefix;
  }

  const { Items } = await docClient.send(new QueryCommand(params));
  return (Items as T[]) || [];
}

Definicion de infraestructura con AWS CDK

> Define un stack de Lambda + API Gateway + DynamoDB con CDK.

// lib/api-stack.ts
import * as cdk from 'aws-cdk-lib';
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as apigateway from 'aws-cdk-lib/aws-apigateway';
import * as dynamodb from 'aws-cdk-lib/aws-dynamodb';
import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs';
import { Construct } from 'constructs';

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

    // Tabla DynamoDB
    const table = new dynamodb.Table(this, 'MainTable', {
      partitionKey: { name: 'PK', type: dynamodb.AttributeType.STRING },
      sortKey: { name: 'SK', type: dynamodb.AttributeType.STRING },
      billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
      removalPolicy: cdk.RemovalPolicy.RETAIN,
    });

    // Funcion Lambda
    const apiHandler = new NodejsFunction(this, 'ApiHandler', {
      entry: 'src/handlers/api.ts',
      handler: 'handler',
      runtime: lambda.Runtime.NODEJS_20_X,
      architecture: lambda.Architecture.ARM_64,
      memorySize: 256,
      timeout: cdk.Duration.seconds(30),
      environment: {
        TABLE_NAME: table.tableName,
        NODE_OPTIONS: '--enable-source-maps',
      },
      bundling: {
        minify: true,
        sourceMap: true,
      },
    });

    table.grantReadWriteData(apiHandler);

    // API Gateway
    const api = new apigateway.RestApi(this, 'Api', {
      restApiName: 'My API',
      deployOptions: { stageName: 'v1' },
    });

    const users = api.root.addResource('users');
    users.addMethod('GET', new apigateway.LambdaIntegration(apiHandler));
    users.addMethod('POST', new apigateway.LambdaIntegration(apiHandler));
  }
}

Desarrollo local y pruebas

# Ejecucion local con SAM
sam local start-api

# Probar una funcion especifica
sam local invoke ApiHandler -e events/get-users.json

# Despliegue con CDK
cdk deploy --require-approval never

Summary

Combinando AWS Lambda con Claude Code, puedes avanzar eficientemente desde el diseno de arquitectura serverless hasta la escritura de IaC. Consulta tambien la guia de despliegue en AWS y la guia de funciones serverless.

Para mas detalles sobre AWS Lambda, consulta la documentacion oficial de AWS Lambda.