3.js

/* eslint-disable no-console */

import { createLibp2p } from 'libp2p'
import { tcp } from '@libp2p/tcp'
import { mplex } from '@libp2p/mplex'
import { noise } from '@chainsafe/libp2p-noise'
import { floodsub } from '@libp2p/floodsub'
import { bootstrap } from '@libp2p/bootstrap'
import { pubsubPeerDiscovery } from '@libp2p/pubsub-peer-discovery'

const createNode = async (bootstrappers) => {
  const node = await createLibp2p({
    addresses: {
      listen: ['/ip4/0.0.0.0/tcp/0']
    },
    transports: [tcp()],
    streamMuxers: [mplex()],
    connectionEncryption: [noise()],
    pubsub: floodsub(),
    peerDiscovery: [
      bootstrap({
        list: bootstrappers
      }),
      pubsubPeerDiscovery({
        interval: 1000
      })
    ]
  })

  return node
}

;(async () => {
  const relay = await createLibp2p({
    addresses: {
      listen: [
        '/ip4/0.0.0.0/tcp/0'
      ]
    },
    transports: [tcp()],
    streamMuxers: [mplex()],
    connectionEncryption: [noise()],
    pubsub: floodsub(),
    peerDiscovery: [
      pubsubPeerDiscovery({
        interval: 1000
      })
    ],
    relay: {
      enabled: true, // Allows you to dial and accept relayed connections. Does not make you a relay.
      hop: {
        enabled: true // Allows you to be a relay for other peers
      }
    }
  })
  console.log(`libp2p relay starting with id: ${relay.peerId.toString()}`)
  await relay.start()

  const relayMultiaddrs = relay.getMultiaddrs().map((m) => m.toString())

  const [node1, node2] = await Promise.all([
    createNode(relayMultiaddrs),
    createNode(relayMultiaddrs)
  ])

  node1.addEventListener('peer:discovery', (evt) => {
    const peer = evt.detail
    console.log(`Peer ${node1.peerId.toString()} discovered: ${peer.id.toString()}`)
  })
  node2.addEventListener('peer:discovery', (evt) => {
    const peer = evt.detail
    console.log(`Peer ${node2.peerId.toString()} discovered: ${peer.id.toString()}`)
  })

  ;[node1, node2].forEach((node, index) => console.log(`Node ${index} starting with id: ${node.peerId.toString()}`))
  await Promise.all([
    node1.start(),
    node2.start()
  ])
})()