fix: replace peerInfo addresses with listen addresses (#485)

* feat: replace peer info addresses with listen addresses

* test: add listening test

* chore: fix linting

Author: dirkmc

src/index.js

@@ -301,10 +301,18 @@ class Libp2p extends EventEmitter {
   }
 
   async _onStarting () {
+    // Listen on the addresses supplied in the peerInfo
     const multiaddrs = this.peerInfo.multiaddrs.toArray()
 
     await this.transportManager.listen(multiaddrs)
 
+    // The addresses may change once the listener starts
+    // eg /ip4/0.0.0.0/tcp/0 => /ip4/192.168.1.0/tcp/58751
+    this.peerInfo.multiaddrs.clear()
+    for (const ma of this.transportManager.getAddrs()) {
+      this.peerInfo.multiaddrs.add(ma)
+    }
+
     if (this._config.pubsub.enabled) {
       this.pubsub && this.pubsub.start()
     }

test/core/listening.node.js

@@ -0,0 +1,56 @@
+'use strict'
+/* eslint-env mocha */
+
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const { expect } = chai
+
+const multiaddr = require('multiaddr')
+const Transport = require('libp2p-tcp')
+
+const { create } = require('../../src')
+const peerUtils = require('../utils/creators/peer')
+
+const listenAddr = multiaddr('/ip4/0.0.0.0/tcp/0')
+
+describe('Listening', () => {
+  let peerInfo
+  let libp2p
+
+  before(async () => {
+    [peerInfo] = await peerUtils.createPeerInfoFromFixture(1)
+    peerInfo.multiaddrs.add(listenAddr)
+  })
+
+  after(async () => {
+    await libp2p.stop()
+  })
+
+  it('should replace wildcard host and port with actual host and port on startup', async () => {
+    libp2p = await create({
+      peerInfo,
+      modules: {
+        transport: [Transport]
+      }
+    })
+
+    await libp2p.start()
+
+    const addrs = libp2p.peerInfo.multiaddrs.toArray()
+
+    // Should get something like:
+    //   /ip4/127.0.0.1/tcp/50866
+    //   /ip4/192.168.1.2/tcp/50866
+    expect(addrs.length).to.equal(2)
+
+    const opts = [addrs[0].toOptions(), addrs[1].toOptions()]
+    expect(opts[0].family).to.equal('ipv4')
+    expect(opts[1].family).to.equal('ipv4')
+    expect(opts[0].transport).to.equal('tcp')
+    expect(opts[1].transport).to.equal('tcp')
+    expect(opts[0].host).to.match(/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/)
+    expect(opts[1].host).to.match(/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/)
+    expect(opts[0].port).to.be.gt(0)
+    expect(opts[1].port).to.be.gt(0)
+  })
+})