spdy

What is spdy?

The spdy npm package is designed to support the SPDY and HTTP/2 protocols in Node.js. It provides server and client functionality, allowing developers to create SPDY/HTTP2 servers and clients with ease. This package is particularly useful for improving web application performance by leveraging the advanced features of these protocols, such as multiplexing, server push, and header compression.

What are spdy's main functionalities?

Creating an SPDY/HTTP2 server

This code sample demonstrates how to create a simple SPDY/HTTP2 server using the spdy package along with Express. It sets up a server that listens on port 3000 and serves a simple message over SPDY/HTTP2.

const spdy = require('spdy');
const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.end('Hello over SPDY/HTTP2');
});

const options = {
  key: fs.readFileSync('<path-to-key>'),
  cert: fs.readFileSync('<path-to-cert>')
};

spdy.createServer(options, app).listen(3000, () => {
  console.log('Server is running on https://localhost:3000');
});

Creating an SPDY/HTTP2 client

This code sample shows how to create an SPDY/HTTP2 client that connects to a server. It demonstrates making a request to the server and handling the response, including reading response headers and data.

const spdy = require('spdy');
const http2 = require('http2');

const client = spdy.connect('https://localhost:3000', (err, socket) => {
  if (err) {
    throw new Error('Connection failed');
  }

  const req = http2.request({
    ':path': '/'
  });

  req.on('response', (headers) => {
    console.log('Response headers:', headers);
  });

  req.setEncoding('utf8');
  req.on('data', (chunk) => console.log(chunk));
  req.end();
});

Other packages similar to spdy

http2

The http2 package is a core module in Node.js that provides an implementation of the HTTP/2 protocol. It offers similar functionalities to spdy, such as creating servers and clients that can communicate over HTTP/2. However, spdy provides additional support for the SPDY protocol, which is not covered by the http2 module.

node-http2

node-http2 is an npm package that also implements the HTTP/2 protocol. It provides an API for creating HTTP/2 servers and clients. Compared to spdy, node-http2 focuses solely on HTTP/2 without support for SPDY. spdy might offer a more comprehensive solution for developers looking to support both protocols.

README

SPDY Server for node.js

With this module you can create HTTP2 / SPDY servers in node.js with natural http module interface and fallback to regular https (for browsers that don't support neither HTTP2, nor SPDY yet).

Usage

Server:

var spdy = require('spdy'),
    fs = require('fs');

var options = {
  key: fs.readFileSync(__dirname + '/keys/spdy-key.pem'),
  cert: fs.readFileSync(__dirname + '/keys/spdy-cert.pem'),
  ca: fs.readFileSync(__dirname + '/keys/spdy-ca.pem'),

  // **optional** SPDY-specific options
  spdy: {
    protocols: [ 'h2', 'spdy/3.1', ..., 'http/1.1' ],
    plain: false,

    // **optional**
    // Parse first incoming X_FORWARDED_FOR frame and put it to the
    // headers of every request.
    // NOTE: Use with care! This should not be used without some proxy that
    // will *always* send X_FORWARDED_FOR
    'x-forwarded-for': true,

    connection: {
      windowSize: 1024 * 1024, // Server's window size

      // **optional** if true - server will send 3.1 frames on 3.0 *plain* spdy
      autoSpdy31: false
    }
  }
};

var server = spdy.createServer(options, function(req, res) {
  res.writeHead(200);
  res.end('hello world!');
});

server.listen(3000);

Client:

var spdy = require('spdy');
var http = require('http');

var agent = spdy.createAgent({
  host: 'www.google.com',
  port: 443,

  // Optional SPDY options
  spdy: {
    plain: false or true,
    ssl: false or true,

    // **optional** send X_FORWARDED_FOR
    'x-forwarded-for': '127.0.0.1'
  }
});

http.get({
  host: 'www.google.com',
  agent: agent
}, function(response) {
  console.log('yikes');
  // Here it goes like with any other node.js HTTP request
  // ...
  // And once we're done - we may close TCP connection to server
  // NOTE: All non-closed requests will die!
  agent.close();
}).end();

Please note that if you use a custom agent, by default all connection-level errors will result in an uncaught exception. To handle these errors subscribe to the error event and re-emit the captured error:

var agent = spdy.createAgent({
  host: 'www.google.com',
  port: 443
}).once('error', function (err) {
  this.emit(err);
});

API

API is compatible with http and https module, but you can use another function as base class for SPDYServer.

spdy.createServer(
  [base class constructor, i.e. https.Server],
  { /* keys and options */ }, // <- the only one required argument
  [request listener]
).listen([port], [host], [callback]);

Request listener will receive two arguments: request and response. They're both instances of http's IncomingMessage and OutgoingMessage. But three custom properties are added to both of them: isSpdy, spdyVersion. isSpdy is true when the request was processed using HTTP2/SPDY protocols, it is false in case of HTTP/1.1 fallback. spdyVersion is either of: 2, 3, 3.1, or 4 (for HTTP2).

Push streams

It is possible to initiate PUSH_PROMISE to send content to clients before the client requests it.

spdy.createServer(options, function(req, res) {
  var stream = res.push('/main.js', {
    status: 200, // optional
    method: 'GET', // optional
    request: {
      accept: '*/*'
    },
    response: {
      'content-type': 'application/javascript'
    }
  });
  stream.on('error', function() {
  });
  stream.end('alert("hello from push stream!");');

  res.end('<script src="/main.js"></script>');
}).listen(3000);

PUSH_PROMISE may be sent using the push() method on the current response object. The signature of the push() method is:

.push('/some/relative/url', { request: {...}, response: {...} }, callback)

Second argument contains headers for both PUSH_PROMISE and emulated response. callback will receive two arguments: err (if any error is happened) and a Duplex stream as the second argument.

Client usage:

var agent = spdy.createAgent({ /* ... */ });
var req = http.get({
  host: 'www.google.com',
  agent: agent
}, function(response) {
});
req.on('push', function(stream) {
  stream.on('error', function(err) {
    // Handle error
  });
  // Read data from stream
});

NOTE: You're responsible for the stream object once given it in .push() callback or push event. Hence ignoring error event on it will result in uncaught exception and crash your program.

Trailing headers

Server usage:

function (req, res) {
  // Send trailing headers to client
  res.addTrailers({ header1: 'value1', header2: 'value2' });

  // On client's trailing headers
  req.on('trailers', function(headers) {
    // ...
  });
}

Client usage:

var req = http.request({ agent: spdyAgent, /* ... */ }).function (res) {
  // On server's trailing headers
  res.on('trailers', function(headers) {
    // ...
  });
});
req.write('stuff');
req.addTrailers({ /* ... */ });
req.end();

Options

All options supported by tls work with node-spdy.

Additional options may be passed via spdy sub-object:

• plain - if defined, server will ignore NPN and ALPN data and choose whether to use spdy or plain http by looking at first data packet.
• ssl - if false and options.plain is true, http.Server will be used as a base class for created server.
• maxChunk - if set and non-falsy, limits number of bytes sent in one DATA chunk. Setting it to non-zero value is recommended if you care about interleaving of outgoing data from multiple different streams. (defaults to 8192)
• protocols - list of NPN/ALPN protocols to use (default is: ['h2','spdy/3.1', 'spdy/3', 'spdy/2','http/1.1', 'http/1.0'])
• protocol - use specific protocol if no NPN/ALPN ex In addition,
• maxStreams - set "maximum concurrent streams" protocol option

Contributors

• Fedor Indutny
• Chris Strom
• François de Metz
• Ilya Grigorik
• Roberto Peon
• Tatsuhiro Tsujikawa
• Jesse Cravens

LICENSE

This software is licensed under the MIT License.

Copyright Fedor Indutny, 2015.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.