Reference implementation how to start a Next.js webserver inside a Lambda from API Gateway invocation

lambda-bridge.js

// Reference implementation how to start a Next.js webserver inside a Lambda
// from API Gateway invocation
// https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-develop-integrations-lambda.html

const { request } = require('http');

// Import the generated Next.js server from somewhere
const NextServer = require('./dist');

exports.handler = async function (event) {
  // Deconstruct API Gateway event
  const {
    http: { method, path },
  } = event.requestContext;

  // Start local server and get address once it's running
  const address = await new Promise((resolve) => {
    const server = new NextServer();

    server.listen(
      {
        host: '127.0.0.1',
        port: 0,
      },
      function listeningCallback() {
        const addr = this.address();
        resolve(addr);
      }
    );
  });

  const payload = await new Promise((resolve, reject) => {
    request(
      {
        hostname: '127.0.0.1',
        port: address.port,
        path,
        method,
      },
      (res) => {
        const respBodyChunks = [];
        res.on('data', (chunk) => respBodyChunks.push(Buffer.from(chunk)));
        res.on('error', reject);
        res.on('end', () => {
          const bodyBuffer = Buffer.concat(respBodyChunks);
          resolve({
            statusCode: response.statusCode || 200,
            headers: response.headers,
            body: bodyBuffer.toString('base64'),
            isBase64Encoded: true,
          });
        });
      }
    );
  });

  return payload;
};