simplified example for peer discovery, added some debug output to discoverPeers(), made Peer reference the connection created from createConnection()

examples/PeerDiscovery.js

@@ -2,14 +2,10 @@ var PeerManager = require('../lib/PeerManager');
 var peerman     = new PeerManager();
 
 peerman.discoverPeers(function(err, peers) {
-  // we get an array of peer instances
-  console.log(peers);
-  // the peer manager caches the tried seeds and any results
-  console.log(peerman.seeds);
   // we can use this array of peers to add to the manager
-  peers.forEach(function(p) {
-    peerman.addPeer(p);
-  });
+  // but let's limit it to 6 connections for this example
+  var p = 0;
+  do { peerman.addPeer(peers[p]); p++; } while (p <= 6);
   // then we can start the manager
   peerman.start();
 });

lib/Peer.js

@@ -34,8 +34,8 @@ function Peer(host, port, services) {
 Peer.IPV6_IPV4_PADDING = new Buffer([0,0,0,0,0,0,0,0,0,0,255,255]);
 
 Peer.prototype.createConnection = function () {
-  var c = Net.createConnection(this.port, this.host);
-  return c;
+  this.connection = Net.createConnection(this.port, this.host);
+  return this.connection;
 };
 
 Peer.prototype.getHostAsBuffer = function () {

lib/PeerManager.js

@@ -26,6 +26,13 @@ function PeerManager(config) {
   this.interval = 5000;
   this.minConnections = 8;
   this.minKnownPeers = 10;
+
+  // keep track of tried seeds and results
+  this.seeds = {
+    resolved: [],
+    failed: [],
+    results: {}
+  };
 }
 
 PeerManager.parent = imports.parent || require('events').EventEmitter;
@@ -219,13 +226,6 @@ PeerManager.prototype.discoverPeers = function(callback) {
   var networks = imports.networks || require('../networks')[this.config.network];
   var seeds    = networks.dnsSeeds;
 
-  // keep track of tried seeds and results
-  self.seeds = {
-    resolved: [],
-    failed: [],
-    results: {}
-  };
-
   var dnsExecutor = seeds.map(function(seed) {
     return function(done) {
       // have we already resolved this seed?
@@ -234,16 +234,19 @@ PeerManager.prototype.discoverPeers = function(callback) {
         return done(null, self.seeds.results[seed]);
       }
       // has this seed failed to resolve?
-      if (~self.seeds.resolved.indexOf(seed)) {
+      if (~self.seeds.failed.indexOf(seed)) {
         // if so, pass back empty results
         return done(null, []);
       }
       // otherwise resolve the dns seed to get some peers
+      log.info('resolving dns seed '+ seed);
       dns.resolve(seed, function(err, peers) {
         if (err) {
+          log.err('failed to resolve dns seed '+ seed, err);
           self.seeds.failed.push(seed);
           return done(null, []);
         }
+        log.info('found '+ peers.length + ' peers from ' + seed);
         self.seeds.resolved.push(seed);
         self.seeds.results[seed] = peers;
         return done(null, peers);