refactor: examples/encrypted-communications (#499)

* refactor: examples/encrypted-communications

* chore: address review

Author: vasco-santos

examples/encrypted-communications/1.js

@@ -1,63 +1,52 @@
 'use strict'
 
-const libp2p = require('../../')
+const Libp2p = require('../../')
 const TCP = require('libp2p-tcp')
-const SPDY = require('libp2p-spdy')
+const Mplex = require('libp2p-mplex')
 const SECIO = require('libp2p-secio')
 const PeerInfo = require('peer-info')
-const waterfall = require('async/waterfall')
-const parallel = require('async/parallel')
-const pull = require('pull-stream')
-const defaultsDeep = require('@nodeutils/defaults-deep')
-
-class MyBundle extends libp2p {
-  constructor (_options) {
-    const defaults = {
-      modules: {
-        transport: [ TCP ],
-        streamMuxer: [ SPDY ],
-        connEncryption: [ SECIO ]
-      }
-    }
 
-    super(defaultsDeep(_options, defaults))
-  }
-}
+const pipe = require('it-pipe')
 
-function createNode (callback) {
-  let node
-
-  waterfall([
-    (cb) => PeerInfo.create(cb),
-    (peerInfo, cb) => {
-      peerInfo.multiaddrs.add('/ip4/0.0.0.0/tcp/0')
-      node = new MyBundle({
-        peerInfo
-      })
-      node.start(cb)
+const createNode = async () => {
+  const peerInfo = await PeerInfo.create()
+  peerInfo.multiaddrs.add('/ip4/0.0.0.0/tcp/0')
+
+  const node = await Libp2p.create({
+    peerInfo,
+    modules: {
+      transport: [TCP],
+      streamMuxer: [Mplex],
+      connEncryption: [SECIO]
     }
-  ], (err) => callback(err, node))
-}
+  })
 
-parallel([
-  (cb) => createNode(cb),
-  (cb) => createNode(cb)
-], (err, nodes) => {
-  if (err) { throw err }
+  await node.start()
 
-  const node1 = nodes[0]
-  const node2 = nodes[1]
+  return node
+}
 
-  node2.handle('/a-protocol', (protocol, conn) => {
-    pull(
-      conn,
-      pull.map((v) => v.toString()),
-      pull.log()
+;(async () => {
+  const [node1, node2] = await Promise.all([
+    createNode(),
+    createNode()
+  ])
+
+  node2.handle('/a-protocol', ({ stream }) => {
+    pipe(
+      stream,
+      async function (source) {
+        for await (const msg of source) {
+          console.log(msg.toString())
+        }
+      }
     )
   })
 
-  node1.dialProtocol(node2.peerInfo, '/a-protocol', (err, conn) => {
-    if (err) { throw err }
-    pull(pull.values(['This information is sent out encrypted to the other peer']), conn)
-  })
-})
+  const { stream } = await node1.dialProtocol(node2.peerInfo, '/a-protocol')
+
+  await pipe(
+    ['This information is sent out encrypted to the other peer'],
+    stream
+  )
+})();

examples/encrypted-communications/README.md

@@ -4,32 +4,29 @@ libp2p can leverage the encrypted communications from the transports it uses (i.
 
 We call this usage a _connection upgrade_ where given a connection between peer A to peer B, a protocol handshake can be performed that gives that connection new properties.
 
-A byproduct of having these encrypted communications modules is that we can authenticate the peers we are dialing to. You might have noticed that every time we dial to a peer in libp2p space, we always use its PeerId at the end (e.g /ip4/127.0.0.1/tcp/89765/ipfs/QmWCbVw1XZ8hiYBwwshPce2yaTDYTqTaP7GCHGpry3ykWb), this PeerId is generated by hashing the Public Key of the peer. With this, we can create a crypto challenge when dialing to another peer and prove that peer is the owner of a PrivateKey that matches the Public Key we know.
+A byproduct of having these encrypted communications modules is that we can authenticate the peers we are dialing to. You might have noticed that every time we dial to a peer in libp2p space, we always use its PeerId at the end (e.g /ip4/127.0.0.1/tcp/89765/p2p/QmWCbVw1XZ8hiYBwwshPce2yaTDYTqTaP7GCHGpry3ykWb), this PeerId is generated by hashing the Public Key of the peer. With this, we can create a crypto challenge when dialing to another peer and prove that peer is the owner of a PrivateKey that matches the Public Key we know.
 
 # 1. Set up encrypted communications with SECIO
 
 We will build this example on top of example for [Protocol and Stream Multiplexing](../protocol-and-stream-multiplexing). You will need the module `libp2p-secio` to complete it, go ahead and `npm install libp2p-secio`.
 
 SECIO is the crypto channel developed for IPFS, it is a TLS 1.3 like crypto channel that established an encrypted communication channel between two peers.
 
-To add it to your libp2p bundle, all you have to do is:
+To add it to your libp2p configuration, all you have to do is:
 
 ```JavaScript
+const Libp2p = require('libp2p')
 const SECIO = require('libp2p-secio')
 
-class MyBundle extends libp2p {
-  constructor (peerInfo) {
-    const defaults = {
-      modules: {
-        transport: [ TCP ],
-        streamMuxer: [ SPDY ],
-        // Attach secio as the crypto channel to use
-        connEncryption: [ SECIO ]
-      }
+const createNode = () => {
+  return Libp2p.create({
+    modules: {
+      transport: [ TCP ],
+      streamMuxer: [ Mplex ],
+      // Attach secio as the crypto channel to use
+      connEncryption: [ SECIO ]
     }
-
-    super(defaultsDeep(_options, defaults))
-  }
+  })
 }
 ```