cloud-platforms

Cloud Platforms

Overview

Cloud services, serverless architectures, and cloud-native development patterns for AWS, GCP, and Azure.

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AWS

Lambda Functions

// lambda/handler.ts
import { APIGatewayProxyHandler, APIGatewayProxyResult } from 'aws-lambda';

export const handler: APIGatewayProxyHandler = async (event) => {
  try {
    const body = JSON.parse(event.body || '{}');

    // Business logic
    const result = await processRequest(body);

    return {
      statusCode: 200,
      headers: {
        'Content-Type': 'application/json',
        'Access-Control-Allow-Origin': '*',
      },
      body: JSON.stringify(result),
    };
  } catch (error) {
    console.error('Handler error:', error);

    return {
      statusCode: error.statusCode || 500,
      body: JSON.stringify({
        error: error.message || 'Internal server error',
      }),
    };
  }
};

// With middleware (middy)
import middy from '@middy/core';
import jsonBodyParser from '@middy/http-json-body-parser';
import httpErrorHandler from '@middy/http-error-handler';
import cors from '@middy/http-cors';

const baseHandler = async (event) => {
  // event.body is already parsed
  return {
    statusCode: 200,
    body: JSON.stringify({ data: event.body }),
  };
};

export const handler = middy(baseHandler)
  .use(jsonBodyParser())
  .use(httpErrorHandler())
  .use(cors());

S3 Operations

import { S3Client, PutObjectCommand, GetObjectCommand } from '@aws-sdk/client-s3';
import { getSignedUrl } from '@aws-sdk/s3-request-presigner';

const s3 = new S3Client({ region: process.env.AWS_REGION });

// Upload file
async function uploadFile(key: string, body: Buffer, contentType: string) {
  await s3.send(new PutObjectCommand({
    Bucket: process.env.S3_BUCKET,
    Key: key,
    Body: body,
    ContentType: contentType,
  }));

  return `https://${process.env.S3_BUCKET}.s3.amazonaws.com/${key}`;
}

// Generate presigned upload URL
async function getUploadUrl(key: string, contentType: string, expiresIn = 3600) {
  const command = new PutObjectCommand({
    Bucket: process.env.S3_BUCKET,
    Key: key,
    ContentType: contentType,
  });

  return getSignedUrl(s3, command, { expiresIn });
}

// Generate presigned download URL
async function getDownloadUrl(key: string, expiresIn = 3600) {
  const command = new GetObjectCommand({
    Bucket: process.env.S3_BUCKET,
    Key: key,
  });

  return getSignedUrl(s3, command, { expiresIn });
}