feat: add libp2p factory config option with example

README.md

@@ -301,8 +301,11 @@ Modify the default IPFS node config. This object will be *merged* with the defau
 | Type | Default |
 |------|---------|
 | object | [`libp2p-nodejs.js`](https://github.com/ipfs/js-ipfs/blob/master/src/core/runtime/libp2p-nodejs.js) in Node.js, [`libp2p-browser.js`](https://github.com/ipfs/js-ipfs/blob/master/src/core/runtime/libp2p-browser.js) in browsers |
+| function | [`libp2p factory`](examples/custom-libp2p) |
 
-Add custom modules to the libp2p stack of your node.
+The libp2p option allows you to build your libp2p node by configuration, or via a factory. If you are looking to just modify the below options, using the object format is the quickest way to get the default features of libp2p. If you need to create a more customized libp2p node, such as with custom transports or peer/content routers that need some of the ipfs data on startup, a factory is a great way to achieve this.
+
+You can see the factory in action in the [custom libp2p example](examples/custom-libp2p).
 
 - `modules` (object):
     - `transport` (Array<[libp2p.Transport](https://github.com/libp2p/interface-transport)>): An array of Libp2p transport classes/instances to use _instead_ of the defaults. See [libp2p/interface-transport](https://github.com/libp2p/interface-transport) for details.

examples/custom-libp2p/README.md

@@ -0,0 +1,18 @@
+# Customizing the libp2p node
+
+This example shows you how to make full use of the ipfs configuration to create a libp2p factory function. As IPFS applications become more complex, their needs for a custom libp2p node also grow. Instead of fighting with configuration options, you can use your own libp2p factory to get exactly what you need. This example shows you how.
+
+## Run this example
+
+Running this example should result in metrics being logged out to the console every few seconds.
+
+```
+> npm install
+> npm start
+```
+
+## Play with the configuration!
+
+With the metrics for peers and bandwidth stats being logged out, try playing around with the nodes configuration to see what kind of metrics you can get. How many peers are you getting? What does your bandwidth look like?
+
+This is also a good opportunity to explore the various stats that ipfs offers! Not seeing a statistic you think would be useful? We'd love to have you [contribute](https://github.com/ipfs/js-ipfs/blob/master/CONTRIBUTING.md)!

examples/custom-libp2p/index.js

@@ -0,0 +1,129 @@
+'use strict'
+
+const Libp2p = require('libp2p')
+const IPFS = require('ipfs')
+const TCP = require('libp2p-tcp')
+const MulticastDNS = require('libp2p-mdns')
+const WebSocketStar = require('libp2p-websocket-star')
+const Bootstrap = require('libp2p-railing')
+const SPDY = require('libp2p-spdy')
+const KadDHT = require('libp2p-kad-dht')
+const MPLEX = require('libp2p-mplex')
+const SECIO = require('libp2p-secio')
+const assert = require('assert')
+
+/**
+ * Options for the libp2p factory
+ * @typedef {Object} libp2pFactory~options
+ * @property {PeerInfo} peerInfo - The PeerInfo of the IPFS node
+ * @property {PeerBook} peerBook - The PeerBook of the IPFS node
+ * @property {Object} config - The config of the IPFS node
+ * @property {Object} options - The options given to the IPFS node
+ */
+
+/**
+ * This is the factory we will use to create our fully customized libp2p node.
+ *
+ * @param {libp2pFactory~options} opts The options to use when generating the libp2p node
+ * @returns {Libp2p} Our new libp2p node
+ */
+const libp2pFactory = (opts) => {
+  // Set convenience variables to clearly showcase some of the useful things that are available
+  const peerInfo = opts.peerInfo
+  const peerBook = opts.peerBook
+  const bootstrapList = opts.config.Bootstrap
+
+  // Create our WebSocketStar transport and give it our PeerId, straight from the ipfs node
+  const wsstar = new WebSocketStar({
+    id: peerInfo.id
+  })
+
+  // Build and return our libp2p node
+  return new Libp2p({
+    peerInfo,
+    peerBook,
+    // Lets limit the connection managers peers and have it check peer health less frequently
+    connectionManager: {
+      maxPeers: 25,
+      pollInterval: 5000
+    },
+    modules: {
+      transport: [
+        TCP,
+        wsstar
+      ],
+      streamMuxer: [
+        MPLEX,
+        SPDY
+      ],
+      connEncryption: [
+        SECIO
+      ],
+      peerDiscovery: [
+        MulticastDNS,
+        Bootstrap,
+        wsstar.discovery
+      ],
+      dht: KadDHT
+    },
+    config: {
+      peerDiscovery: {
+        mdns: {
+          interval: 10000,
+          enabled: true
+        },
+        bootstrap: {
+          interval: 10000,
+          enabled: true,
+          list: bootstrapList
+        }
+      },
+      // Turn on relay with hop active so we can connect to more peers
+      relay: {
+        enabled: true,
+        hop: {
+          enabled: true,
+          active: true
+        }
+      },
+      dht: {
+        kBucketSize: 20
+      },
+      EXPERIMENTAL: {
+        dht: true,
+        pubsub: true
+      }
+    }
+  })
+}
+
+// Now that we have our custom factory, let's start up the ipfs node!
+const node = new IPFS({
+  libp2p: libp2pFactory
+})
+
+// Listen for the node to start, so we can log out some metrics
+node.once('start', (err) => {
+  assert.ifError(err, 'Should startup without issue')
+
+  // Lets log out the number of peers we have every 2 seconds
+  setInterval(() => {
+    node.swarm.peers((err, peers) => {
+      if (err) {
+        console.log('An error occurred trying to check our peers:', err)
+        process.exit(1)
+      }
+      console.log(`The node now has ${peers.length} peers.`)
+    })
+  }, 2000)
+
+  // Log out the bandwidth stats every 4 seconds so we can see how our configuration is doing
+  setInterval(() => {
+    node.stats.bw((err, stats) => {
+      if (err) {
+        console.log('An error occurred trying to check our stats:', err)
+      }
+      console.log(`\nBandwidth Stats: ${JSON.stringify(stats, null, 2)}\n`)
+    })
+  }, 4000)
+})

examples/custom-libp2p/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "custom-libp2p",
+  "version": "0.1.0",
+  "description": "Customizing your libp2p node",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "start": "node index.js"
+  },
+  "license": "MIT",
+  "dependencies": {
+    "ipfs": "file:../../",
+    "libp2p": "~0.22.0",
+    "libp2p-kad-dht": "~0.10.1",
+    "libp2p-mdns": "~0.12.0",
+    "libp2p-mplex": "~0.8.0",
+    "libp2p-railing": "~0.9.2",
+    "libp2p-secio": "~0.10.0",
+    "libp2p-spdy": "~0.12.1",
+    "libp2p-tcp": "~0.12.0",
+    "libp2p-websocket-star": "~0.8.1"
+  }
+}

src/core/components/libp2p.js

@@ -16,49 +16,64 @@ module.exports = function libp2p (self) {
           return callback(err)
         }
 
-        const libp2pDefaults = {
-          peerInfo: self._peerInfo,
-          peerBook: self._peerInfoBook,
-          config: {
-            peerDiscovery: {
-              mdns: {
-                enabled: get(self._options, 'config.Discovery.MDNS.Enabled',
-                  get(config, 'Discovery.MDNS.Enabled', true))
+        const defaultFactory = (opts) => {
+          const libp2pDefaults = {
+            peerInfo: opts.peerInfo,
+            peerBook: opts.peerBook,
+            config: {
+              peerDiscovery: {
+                mdns: {
+                  enabled: get(opts.options, 'config.Discovery.MDNS.Enabled',
+                    get(opts.config, 'Discovery.MDNS.Enabled', true))
+                },
+                webRTCStar: {
+                  enabled: get(opts.options, 'config.Discovery.webRTCStar.Enabled',
+                    get(opts.config, 'Discovery.webRTCStar.Enabled', true))
+                },
+                bootstrap: {
+                  list: get(opts.options, 'config.Bootstrap',
+                    get(opts.config, 'Bootstrap', []))
+                }
               },
-              webRTCStar: {
-                enabled: get(self._options, 'config.Discovery.webRTCStar.Enabled',
-                  get(config, 'Discovery.webRTCStar.Enabled', true))
+              relay: {
+                enabled: get(opts.options, 'relay.enabled',
+                  get(opts.config, 'relay.enabled', false)),
+                hop: {
+                  enabled: get(opts.options, 'relay.hop.enabled',
+                    get(opts.config, 'relay.hop.enabled', false)),
+                  active: get(opts.options, 'relay.hop.active',
+                    get(opts.config, 'relay.hop.active', false))
+                }
               },
-              bootstrap: {
-                list: get(self._options, 'config.Bootstrap',
-                  get(config, 'Bootstrap', []))
-              }
-            },
-            relay: {
-              enabled: get(self._options, 'relay.enabled',
-                get(config, 'relay.enabled', false)),
-              hop: {
-                enabled: get(self._options, 'relay.hop.enabled',
-                  get(config, 'relay.hop.enabled', false)),
-                active: get(self._options, 'relay.hop.active',
-                  get(config, 'relay.hop.active', false))
+              EXPERIMENTAL: {
+                dht: get(opts.options, 'EXPERIMENTAL.dht', false),
+                pubsub: get(opts.options, 'EXPERIMENTAL.pubsub', false)
               }
             },
-            EXPERIMENTAL: {
-              dht: get(self._options, 'EXPERIMENTAL.dht', false),
-              pubsub: get(self._options, 'EXPERIMENTAL.pubsub', false)
-            }
-          },
-          connectionManager: get(self._options, 'connectionManager',
-            get(config, 'connectionManager', {}))
+            connectionManager: get(opts.options, 'connectionManager',
+              get(opts.config, 'connectionManager', {}))
+          }
+
+          const libp2pOptions = defaultsDeep(
+            get(self._options, 'libp2p', {}),
+            libp2pDefaults
+          )
+
+          return new Node(libp2pOptions)
         }
 
-        const libp2pOptions = defaultsDeep(
-          get(self._options, 'libp2p', {}),
-          libp2pDefaults
-        )
+        // Always create libp2p via a factory
+        let libp2pFactory = get(self._options, 'libp2p', null)
+        if (typeof libp2pFactory !== 'function') {
+          libp2pFactory = defaultFactory
+        }
 
-        self._libp2pNode = new Node(libp2pOptions)
+        self._libp2pNode = libp2pFactory({
+          options: self._options,
+          config: config,
+          peerInfo: self._peerInfo,
+          peerBook: self._peerInfoBook
+        })
 
         self._libp2pNode.on('peer:discovery', (peerInfo) => {
           const dial = () => {

src/core/config.js

@@ -48,9 +48,12 @@ const schema = Joi.object().keys({
     }).allow(null),
     Bootstrap: Joi.array().items(Joi.multiaddr().IPFS().options({ convert: false }))
   }).allow(null),
-  libp2p: Joi.object().keys({
-    modules: Joi.object().allow(null) // TODO: schemas for libp2p modules?
-  }).allow(null)
+  libp2p: Joi.alternatives().try(
+    Joi.func(),
+    Joi.object().keys({
+      modules: Joi.object().allow(null) // TODO: schemas for libp2p modules?
+    })
+  ).allow(null)
 }).options({ allowUnknown: true })
 
 module.exports.validate = (config) => Joi.attempt(config, schema)

test/core/config.spec.js

@@ -226,6 +226,7 @@ describe('config', () => {
       { libp2p: { modules: null } },
       { libp2p: { modules: undefined } },
       { libp2p: { unknown: 'value' } },
+      { libp2p: () => {} },
       { libp2p: null },
       { libp2p: undefined }
     ]