libp2p-webrtc-star

js-libp2p-webrtc-star

libp2p WebRTC transport that includes a discovery mechanism provided by the signalling-star

Description

libp2p-webrtc-star is one of the WebRTC transports available for libp2p. `libp2p-webrtc-star incorporates both a transport and a discovery service that is facilitated by the signalling server, also part of this module.

Usage

Installation

> npm install libp2p-webrtc-star

API

Using this module in Node.js (and not in the browser)

To use this module in Node.js, you have to BYOI of WebRTC, there are multiple options out there, unfortunately, none of them are 100% solid. The ones we recommend are: wrtc and electron-webrtc.

Instead of just creating the WebRTCStar instance without arguments, you need to pass an options object with the WebRTC implementation:

const wrtc = require('wrtc')
const electronWrtc = require('electron-wrtc')
const WStar = require('libp2p-webrtc-star')

// Using wrtc
const ws1 = new WStar({ wrtc: wrtc })

// Using electron-webrtc
const ws2 = new WStar({ wrtc: electronWebRTC() })

Rendezvous server (aka Signalling server)

Nodes using libp2p-webrtc-star will connect to a known point in the network, a rendezvous point where they can learn about other nodes (Discovery) and exchange their SDP offers (signalling data).

libp2p-webrtc-star comes with its own signalling server, used for peers to handshake their signalling data and establish a connection. You can install it in your machine by installing the module globally:

> npm install --global libp2p-webrtc-star

This will expose a webrtc-star cli tool. To spawn a server do:

> star-signal --port=9090 --host=127.0.0.1

Defaults:

• port - 13579
• host - '0.0.0.0'

Hosted Rendezvous Server

We host a signalling server at star-signal.cloud.ipfs.team that can be used for practical demos and experimentation, it should not be used for apps in production. A libp2p-webrtc-star address, using the signalling server we provide, looks like:

/dns4/star-signal.cloud.ipfs.team/wss/p2p-webrtc-star/ipfs/<your-peer-id>

Note: The address above indicates WebSockets Secure, which can be accessed from both http and https.

This module uses pull-streams

We expose a streaming interface based on pull-streams, rather then on the Node.js core streams implementation (aka Node.js streams). pull-streams offers us a better mechanism for error handling and flow control guarantees. If you would like to know more about why we did this, see the discussion at this issue.

You can learn more about pull-streams at:

• The history of Node.js streams, nodebp April 2014
• The history of streams, 2016
• pull-streams, the simple streaming primitive
• pull-streams documentation

Converting pull-streams to Node.js Streams

If you are a Node.js streams user, you can convert a pull-stream to a Node.js stream using the module pull-stream-to-stream, giving you an instance of a Node.js stream that is linked to the pull-stream. For example:

const pullToStream = require('pull-stream-to-stream')

const nodeStreamInstance = pullToStream(pullStreamInstance)
// nodeStreamInstance is an instance of a Node.js Stream

To learn more about this utility, visit https://pull-stream.github.io/#pull-stream-to-stream.