Node.js Server Reference

Server Object

- For creating TLS/SSL servers

Common Server Methods

Method

Common Server Events

Event

Description

HTTP Server

const http = require('http');
// Create an HTTP server const server = http.createServer((req, res) => {

// Handle requests res.writeHead(200, {'Content - Type': 'text/plain'});

res.end('Hello World\n');
});
// Start the server const PORT = 8080;
server.listen(PORT, () => {
console.log(`Server running at http://localhost:${PORT}/`);
});
// Handle server events server.on('error', (err) => {
console.error(`Server error: ${err.message}`);
});
server.on('close', () => {
console.log('Server closed');
});

HTTPS Server

const https = require('https');
const fs = require('fs');
// SSL options - in a production environment, use properly signed certificates const options = {
key: fs.readFileSync('server-key.pem'),  // Path to your key file cert: fs.readFileSync('server-cert.pem') // Path to your certificate file
};
// Create an HTTPS server const server = https.createServer(options, (req, res) => {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello Secure World\n');
});
// Start the server const PORT = 3443;
server.listen(PORT, () => {
console.log(`Server running at https://localhost:${PORT}/`);
});
TCP Server (net.Server)
A TCP server is created using the net.createServer()

const net = require('net');
// Create a TCP server const server = net.createServer((socket) => {
console.log('Client connected');
// Handle data from client socket.on('data', (data) => {
console.log(`Received: ${data}`);
socket.write(`Echo: ${data}`);
});
// Handle client disconnection socket.on('end', () => {
console.log('Client disconnected');
});
// Handle socket errors socket.on('error', (err) => {
console.error(`Socket error: ${err.message}`);
});
});
// Start the server const PORT = 8888;
server.listen(PORT, () => {
console.log(`TCP server listening on port ${PORT}`);
});
// Get server information after it's listening server.on('listening', () => {
const address = server.address();
console.log(`Server info: ${JSON.stringify(address)}`);
});

TLS/SSL Server

A secure TLS/SSL server is created using the tls.createServer()

const tls = require('tls');
const fs = require('fs');
// SSL options const options = {

key: fs.readFileSync('server - key.pem'), cert: fs.readFileSync('server - cert.pem'),

};
// Create a TLS server const server = tls.createServer(options, (socket) => {
console.log('Client connected securely');
// Check if client provided a certificate if (socket.authorized) {
console.log('Client authorized');
} else {
console.log('Client unauthorized');
}
// Handle data from client socket.on('data', (data) => {
console.log(`Received: ${data}`);
socket.write(`Secure echo: ${data}`);
});
// Handle client disconnection socket.on('end', () => {
console.log('Client disconnected');
});
});
// Start the server const PORT = 8443;
server.listen(PORT, () => {
console.log(`TLS server listening on port ${PORT}`);
});

HTTP Server with Routing

const http = require('http');
const url = require('url');
// Create an HTTP server with routing const server = http.createServer((req, res) => {

const parsedUrl = url.parse(req.url, true);
const path = parsedUrl.pathname;
const trimmedPath = path.replace(/^\/+|\/+$/g, '');
// Get the HTTP method const method = req.method.toLowerCase();
// Get query parameters const queryParams = parsedUrl.query;
// Log the request console.log(`Request received: ${method} ${trimmedPath}`);
// Route handler let response = {
status: 404, contentType: 'application/json', payload: { message: 'Not Found' }
};
// Basic routing if (method === 'get') {
if (trimmedPath === '') {
// Home route response = {

status: 200, contentType: 'text/html', payload: '< h1 > Home Page </h1 >< p > Welcome to the server </p >'

};
} else if (trimmedPath === 'api/users') {
// API route - list users response = {
status: 200, contentType: 'application/json', payload: {
users: [
{ id: 1, name: 'John' },
{ id: 2, name: 'Jane' }

}
};
} else if (trimmedPath.startsWith('api/users/')) {

// API route - get user by ID

const userId = trimmedPath.split('/')[2];
response = {
status: 200, contentType: 'application/json', payload: { id: userId, name: `User ${userId}` }
};
}
}
// Return the response res.setHeader('Content-Type', response.contentType);
res.writeHead(response.status);
// Convert payload to string if it's an object const payloadString = typeof response.payload === 'object'
? JSON.stringify(response.payload)
: response.payload;
res.end(payloadString);
});
// Start the server const PORT = 8080;
server.listen(PORT, () => {
console.log(`Server running at http://localhost:${PORT}/`);
});

Server Timeouts and Limits

const http = require('http');
// Create an HTTP server const server = http.createServer((req, res) => {
// Simulating a delayed response setTimeout(() => {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Response after delay\n');
}, 2000);
});
// Configure server timeouts server.timeout = 10000; // 10 seconds (default is 120000 or 2 minutes)
server.keepAliveTimeout = 5000; // 5 seconds (default is 5000)
server.maxHeadersCount = 1000; // Maximum headers count (default is 2000)
server.maxRequestsPerSocket = 100; // Max requests per socket (Node.js 14+)
// Start the server const PORT = 8080;
server.listen(PORT, () => {
console.log(`Server with timeouts configured at http://localhost:${PORT}/`);
// Display the server configuration console.log(`Server timeout: ${server.timeout}ms`);
console.log(`Keep-alive timeout: ${server.keepAliveTimeout}ms`);
console.log(`Max headers count: ${server.maxHeadersCount}`);
console.log(`Max requests per socket: ${server.maxRequestsPerSocket || 'N/A'}`);
});

HTTP/2 Server

Creating an HTTP/2 server (introduced in Node.js v8.4.0):

const http2 = require('http2');
const fs = require('fs');
// SSL options for HTTP/2 const options = {

key: fs.readFileSync('server - key.pem'), cert: fs.readFileSync('server - cert.pem')

};
// Create an HTTP/2 server const server = http2.createSecureServer(options);
// Handle incoming streams server.on('stream', (stream, headers) => {
const path = headers[':path'];
const method = headers[':method'];
console.log(`${method} ${path}`);
// Respond to the request stream.respond({

'content - type': 'text/html',

});
stream.end('<h1>HTTP/2 Server</h1><p>This page was served via HTTP/2</p>');
});
// Start the server const PORT = 8443;
server.listen(PORT, () => {
console.log(`HTTP/2 server running at https://localhost:${PORT}/`);
});

Best Practices

Error handling

Graceful shutdown

Timeouts

Clustering

Https/tls

Connection limits

Monitoring