🔗 나만의 단축 URL 서비스

// createUrl Lambda — URL 생성 함수 (Node.js 20.x 런타임)
import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { PutCommand, DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';
import crypto from 'crypto';
 
const client = DynamoDBDocumentClient.from(new DynamoDBClient({}));
const TABLE = process.env.TABLE_NAME || 'lab-urls';
 
export const handler = async (event) => {
  const { url } = JSON.parse(event.body);
  const shortCode = crypto.createHash('sha256')
    .update(url + Date.now()).digest('hex').slice(0, 8);
 
  await client.send(new PutCommand({
    TableName: TABLE,
    Item: {
      shortId: shortCode,
      originalUrl: url,
      clickCount: 0,
      createdAt: new Date().toISOString(),
      ttl: Math.floor(Date.now() / 1000) + 86400 * 30, // 30일 후 자동 삭제
    },
  }));
 
  return {
    statusCode: 201,
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      shortId: shortCode,
      shortUrl: `https://${event.headers.Host}/${shortCode}`,
    }),
  };
};

// redirectUrl Lambda — 리다이렉트 함수 (Node.js 20.x 런타임)
import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { GetCommand, UpdateCommand, DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';
 
const client = DynamoDBDocumentClient.from(new DynamoDBClient({}));
const TABLE = process.env.TABLE_NAME || 'lab-urls';
 
export const handler = async (event) => {
  const shortCode = event.pathParameters.shortId;
 
  const { Item } = await client.send(new GetCommand({
    TableName: TABLE,
    Key: { shortId: shortCode },
  }));
 
  if (!Item) {
    return { statusCode: 404, body: JSON.stringify({ error: 'URL을 찾을 수 없습니다' }) };
  }
 
  // Atomic counter — 클릭 수 원자적 증가
  await client.send(new UpdateCommand({
    TableName: TABLE,
    Key: { shortId: shortCode },
    UpdateExpression: 'ADD clickCount :inc',
    ExpressionAttributeValues: { ':inc': 1 },
  }));
 
  return {
    statusCode: 301,
    headers: { Location: Item.originalUrl },
  };
};