Running private DHTs

[tetsuo]

README says:

To run a fully private DHT, start two or more dht nodes with an empty bootstrap array (dht({bootstrap:[]})) and then use the addresses of those nodes as the bootrstrap option in all other dht nodes.

But dht({ bootstrap: [] }) never fires a listening event.

Can you show an example for running a private bootstrap node?

[davidmarkclements]

You need to call listen:

const dht = require('@hyperswam/dht')

const node = dht({
  ephemeral: true,
  // make ourselves the bootstrap node
  bootstrap: []
})

node.listen()

node.on('listening', () => {
  const { address, port } = node.address()

  console.log(`listening on ${address}:${port}`)
})

[tetsuo]

Thank you @davidmarkclements

It looks like it is not required to call listen when you have a list of bootstrap nodes already.

const node = dht()
node.on('listening', () => {
  console.log('this fires')
})

[davidmarkclements]

Yeah we should address that with either docs or alter behaviour - @mafintosh what do you think?

[tetsuo]

One more thing:

I'm expecting these two to not connect at all, but they do:

import crypto from 'crypto'
import hyperswarm, { Hyperswarm } from 'hyperswarm'

const topic = crypto.randomBytes(32)

const swx = hyperswarm({ bootstrap: [], ephemeral: true })
const swy = hyperswarm({ bootstrap: [], ephemeral: true })

swx.on('connection', socket => {
  socket.write('a')
})

swy.on('connection', socket => {
  socket.on('data', console.log)
})

swx.join(topic, { lookup: false, announce: true })

swy.join(topic, { lookup: true, announce: false })

[RangerMauve]

Hyperswarm uses MDNS for discovering peers on the local network. That might be how the two are finding each other.

[mafintosh]

We just released local discovery through the DHT yesterday.
If mdns is giving you trouble you can try that using the announceLocalAddress flag.

const swarm = hyperswarm({
  announceLocalAddress: true
})

[tetsuo]

Hyperswarm uses MDNS for discovering peers on the local network. That might be how the two are finding each other.

@RangerMauve

I see now, thanks!! I thought hyperswarm only worked with dht-rpc.

But I guess it's not possible to disable mdns completely:

https://github.com/hyperswarm/discovery/blob/8b41a510b295bbaad1113845f397352545c12fdd/index.js#L152

@mafintosh

Well, if mdns is already working then that means this module acts a little bit differently than its predecessor (discovery-swarm). In discovery-swarm, you receive a connection event for all the different types of connections.

What I'm actually trying to figure out is how to deal with duplicates.

I'm creating a noise-peer socket to authenticate the other end when I receive the connection, but destroying a socket (e.g., throwing 'already connected') starts an infinite reconnection loop.

This of course only happens when a peer has both the announce and lookup flags set.

My workaround is to make a Swarm either an initiator or non-initiator, but not both.

But what I really would love to achieve is:

• to be able to identify if a connection is an initiator or not (using details.client) and initialize the noise stream that way, so I can have a peer that can announce and lookup at the same.

• connect to a peer only once regardless of the connection type and gracefully destroy a socket I received via the connection.

  sw.on('connection', socket => {
    const secure = noise(socket, initiator, {
      pattern: 'XX',
      staticKeyPair: keys,
      onstatickey: (remoteKey, done) => {
        const hex = remoteKey.toString('hex')
        if (remoteKeys.has(hex)) {
          return done(new Error('already connected'))
        }
        remoteKeys.add(hex)
        sockets.set(secure, hex)
        if (onconnect) {
          onconnect(hex)
        }
        if (onupdate) {
          onupdate(remoteKeys)
        }
        done(null)
      }
    })

[tetsuo]

Here is my naive attempt to disable multicast completely:

https://github.com/tetsuo/discovery/commit/116c74c846467996f74545253d4965f33059bd12

sadly {bootstrap: [local], multicast: false} doesn't seem to work

[sallespro]

During V5 exploration, DHT does not seem to fire the listen event when bootstrapped.

const node = new DHT({  ephemeral: true, bootstrap: []});

server.on('listening', () => { console.log(server.address())})

do one need to create two nodes before the first actually listen ?
this is needed to setup the host/post of the second node.

[mafintosh]

@sallespro sorry missed your comment. You need at least one none ephemeral DHT running for a server to announce itself (listen)

[draeder]

I have been struggling all day today to get my private bootstrap DHT to work. This issue is the only place I can find more detailed documentation about it, but it is still not working.

I have my bootstrap server code, bootstrap.js:

import DHT from "@hyperswarm/dht"

const bootstrap = DHT.bootstrapper(10001, "127.0.0.1", { ephemeral: true, bootstrap: [], announceLocalAddress: true })

bootstrap.on('listening', () => {
  console.log(bootstrap.localAddress())
})

bootstrap.on('connection', () => {
  console.log("Got a connection??") // This never fires
})

Then my server & client code, test.js:

import Hyperswarm from "hyperswarm"

const swarm = new Hyperswarm({ bootstrap: ["127.0.0.1:10001" ], ephemeral: true, announceLocalAddress: true })

swarm.on("connection", ()=> {
  console.log("connected!")
})

const topic = Buffer.alloc(32).fill('hello world')
const discovery = swarm.join(topic)
await discovery.flushed()

test.js works fine when I do not try to point it at my bootstrap server. It does not work when I do.

I'm running two instances of test.js as well as bootstrap.js on the same computer, if that's important.

Any direction is greatly appreciated!

[cshotton]

ephemeral: true

I think in your bootstrap server, it is supposed to be ephemeral: false according to the docs. (and other comments here.)