feat: support dial only on transport manager to tolerate errors (#643)

* feat: support dial only on transport manager to tolerate errors

* chore: address review

* chore: add jsdoc to transport manager tolerance errors

src/config.js

@@ -3,6 +3,8 @@
 const mergeOptions = require('merge-options')
 const Constants = require('./constants')
 
+const { FaultTolerance } = require('./transport-manager')
+
 const DefaultConfig = {
   addresses: {
     listen: [],
@@ -12,6 +14,9 @@ const DefaultConfig = {
   connectionManager: {
     minPeers: 25
   },
+  transportManager: {
+    faultTolerance: FaultTolerance.FATAL_ALL
+  },
   dialer: {
     maxParallelDials: Constants.MAX_PARALLEL_DIALS,
     maxDialsPerPeer: Constants.MAX_PER_PEER_DIALS,

src/index.js

@@ -101,7 +101,8 @@ class Libp2p extends EventEmitter {
     // Setup the transport manager
     this.transportManager = new TransportManager({
       libp2p: this,
-      upgrader: this.upgrader
+      upgrader: this.upgrader,
+      faultTolerance: this._options.transportManager.faultTolerance
     })
 
     // Create the Registrar

src/transport-manager.js

@@ -13,12 +13,14 @@ class TransportManager {
    * @param {object} options
    * @param {Libp2p} options.libp2p The Libp2p instance. It will be passed to the transports.
    * @param {Upgrader} options.upgrader The upgrader to provide to the transports
+   * @param {boolean} [options.faultTolerance = FAULT_TOLERANCE.FATAL_ALL] Address listen error tolerance.
    */
-  constructor ({ libp2p, upgrader }) {
+  constructor ({ libp2p, upgrader, faultTolerance = FAULT_TOLERANCE.FATAL_ALL }) {
     this.libp2p = libp2p
     this.upgrader = upgrader
     this._transports = new Map()
     this._listeners = new Map()
+    this.faultTolerance = faultTolerance
   }
 
   /**
@@ -173,7 +175,11 @@ class TransportManager {
     // If no transports were able to listen, throw an error. This likely
     // means we were given addresses we do not have transports for
     if (couldNotListen.length === this._transports.size) {
-      throw errCode(new Error(`no valid addresses were provided for transports [${couldNotListen}]`), codes.ERR_NO_VALID_ADDRESSES)
+      const message = `no valid addresses were provided for transports [${couldNotListen}]`
+      if (this.faultTolerance === FAULT_TOLERANCE.FATAL_ALL) {
+        throw errCode(new Error(message), codes.ERR_NO_VALID_ADDRESSES)
+      }
+      log(`libp2p in dial mode only: ${message}`)
     }
   }
 
@@ -212,4 +218,18 @@ class TransportManager {
   }
 }
 
+/**
+ * Enum Transport Manager Fault Tolerance values.
+ * FATAL_ALL should be used for failing in any listen circumstance.
+ * NO_FATAL should be used for not failing when not listening.
+ * @readonly
+ * @enum {number}
+ */
+const FAULT_TOLERANCE = {
+  FATAL_ALL: 0,
+  NO_FATAL: 1
+}
+
+TransportManager.FaultTolerance = FAULT_TOLERANCE
+
 module.exports = TransportManager