Raspberry Pi -> ESP8266 request forward script in Node.js

main.js

// Use HTTP module
var http = require('http');

// Define a port we want to listen to
const PORT=8000; 

// This function sends requests to the ESP8266
function doRequest(url) {
 try {
  var req = http.get({
      host: '10.0.0.3',
      port: 8000,
      path: '/'+url
    }, function(response) { }
    ).on('error', function(err) {
      // handle errors with the request itself
      console.error('Error with the request:', err.message);
    });
 } catch(e) {
   
 }
}

// This function handles requests
function handleRequest(req, res){

  // Map ID values to LED seqments
  var mapValues = ["1-2", "3-4", "5-6", "7-8", "9-10", "11-12", "13-14", "15-16"];
  // Define pre- and post-delays
  var delay_pre = [4, 8, 12, 16, 20, 24, 28, 32];
  var delay_post = [32, 28, 24, 20, 16, 12, 8, 4];
  var led_on_time = 25;
  
  
  // On /set/, set four states to switch between off and green
  if (req.method === "GET" && req.url.substr(0,4) === "/set") {
    var led_idx = parseInt(req.url[5]);
    // Send request to the ESP8266 (/set/<LED_ids>/<State>/<Red>/<Green>/<Blue>/<Transition time to next state in ticks of 30ms>
    doRequest("set/"+mapValues[led_idx]+"/0/0/0/0/"+delay_pre[led_idx]); // Stay off for delay_pre time
    doRequest("set/"+mapValues[led_idx]+"/1/0/0/0/5");                   // Transition to off-state, and 5 tick transition to "green"
    doRequest("set/"+mapValues[led_idx]+"/2/0/40/0/"+led_on_time);       // Green on-state
    doRequest("set/"+mapValues[led_idx]+"/3/0/0/0/"+delay_post[led_idx]);// Balance the overall delay, so that the LEDs don't go off-sync
    doRequest("cleartime/"); // Clear all timings, so that the sequence blinks as it should
    res.end();
    
  // On /clear/, set four states to switch between off and red
  } else if (req.method === "GET" && req.url.substr(0,6) === "/clear") {
    var led_idx = parseInt(req.url[7]);
    doRequest("set/"+mapValues[led_idx]+"/0/0/0/0/"+delay_pre[led_idx]);
    doRequest("set/"+mapValues[led_idx]+"/1/0/0/0/5");
    doRequest("set/"+mapValues[led_idx]+"/2/40/0/0/"+led_on_time);
    doRequest("set/"+mapValues[led_idx]+"/3/0/0/0/"+delay_post[led_idx]);
    doRequest("cleartime/");
    res.end();
  } else {
    res.statusCode = 404;
    res.end();
  }
}

//Create the server
var server = http.createServer(handleRequest);

// Listen for connections
server.listen(PORT, function(){
  // Listening..
  console.log("Server listening on: http://localhost:%s", PORT);
});