Alexa: Proxy lambda

/** This lambda function will proxy the request to another endpoint, easily allowing local execution of the real implemenation. */
const https = require('https');

exports.handler = function(event, context, callback) {
    console.log(`Connecting to ${process.env.HOSTNAME}${process.env.PATH}.`);

    const postData = JSON.stringify({event, context});
    const options = {
      hostname: process.env.HOSTNAME,
      port: 443,
      path: process.env.PATH,
      method: 'POST',
      headers: {
           'Content-Type': 'application/json',
           'Content-Length': postData.length
         }
    };

    const req = https.request(options, resp => {
      console.log('Waiting for response.');
      let data = '';
      resp.on('data', block => {
          console.log(`New data: ${block}.`);
          data+=block;
      });
      resp.on('end', () => {
        console.log(`Obtained data: ${data}.`);
        const implResponse = JSON.parse(data);
        callback(implResponse.err, implResponse.response);
      });
    }).on("error", err => {
        console.log(`Error: %s.`, JSON.stringify(err));
        callback(err);
    });
    req.write(postData);
    req.end();
};

/** Here it is the other side of the coin: the proxied actual client. */

const isAWSLambda = process.env.LAMBDA_TASK_ROOT && process.env.AWS_EXECUTION_ENV;

if (!isAWSLambda) {
    console.log('Local execution detected. Launching server.');
    var express = require('express');
    var bodyParser = require('body-parser');
    var app = express();
    app.use(bodyParser.json());
    app.post('/', function(req, res) {
        console.log(`New request %s.`, JSON.stringify(req.body));
        exports.handler(req.body.event, req.body.context, (err, response) => {
            const skillResponse = {err, response};
            console.log(`Skill response: %s.`, JSON.stringify(skillResponse));
            res.setHeader('Content-Type', 'application/json');
            res.send(JSON.stringify(skillResponse));
        });
    });
    app.listen(80, function () {
        console.log('Server listening on port 80.');
    });
}