feat: implementing port 0 support (#2125)

apps/wakunode2/app.nim

@@ -8,6 +8,8 @@ import
   stew/results,
   chronicles,
   chronos,
+  libp2p/wire,
+  libp2p/multicodec,
   libp2p/crypto/crypto,
   libp2p/nameresolving/dnsresolver,
   libp2p/protocols/pubsub/gossipsub,
@@ -117,39 +119,8 @@ proc init*(T: type App, rng: ref HmacDrbgContext, conf: WakuNodeConf): T =
       quit(QuitFailure)
     else: netConfigRes.get()
 
-  var enrBuilder = EnrBuilder.init(key)
+  let recordRes = enrConfiguration(conf, netConfig, key)
 
-  enrBuilder.withIpAddressAndPorts(
-    netConfig.enrIp,
-    netConfig.enrPort,
-    netConfig.discv5UdpPort
-  )
-
-  if netConfig.wakuFlags.isSome():
-    enrBuilder.withWakuCapabilities(netConfig.wakuFlags.get())
-
-  enrBuilder.withMultiaddrs(netConfig.enrMultiaddrs)
-
-  let topics =
-    if conf.pubsubTopics.len > 0 or conf.contentTopics.len > 0:
-      let shardsRes = conf.contentTopics.mapIt(getShard(it))
-      for res in shardsRes:
-        if res.isErr():
-          error "failed to shard content topic", error=res.error
-          quit(QuitFailure)
-
-      let shards = shardsRes.mapIt(it.get())
-
-      conf.pubsubTopics & shards
-    else:
-      conf.topics
-
-  let addShardedTopics = enrBuilder.withShardedTopics(topics)
-  if addShardedTopics.isErr():
-      error "failed to add sharded topics to ENR", error=addShardedTopics.error
-      quit(QuitFailure)
-
-  let recordRes = enrBuilder.build()
   let record =
     if recordRes.isErr():
       error "failed to create record", error=recordRes.error
@@ -329,6 +300,72 @@ proc setupWakuApp*(app: var App): AppResult[void] =
 
   ok()
 
+proc getPorts(listenAddrs: seq[MultiAddress]):
+              AppResult[tuple[tcpPort, websocketPort: Option[Port]]] = 
+
+  var tcpPort, websocketPort = none(Port)
+
+  for a in listenAddrs:
+    if a.isWsAddress():
+      if websocketPort.isNone():
+        let wsAddress = initTAddress(a).valueOr:
+          return err("getPorts wsAddr error:" & $error)
+        websocketPort = some(wsAddress.port)
+    elif tcpPort.isNone():
+      let tcpAddress = initTAddress(a).valueOr:
+        return err("getPorts tcpAddr error:" & $error)
+      tcpPort = some(tcpAddress.port)
+
+  return ok((tcpPort: tcpPort, websocketPort: websocketPort))
+
+proc updateNetConfig(app: var App): AppResult[void] =
+
+  var conf = app.conf
+  let (tcpPort, websocketPort) = getPorts(app.node.switch.peerInfo.listenAddrs).valueOr:
+    return err("Could not retrieve ports " & error)
+
+  if tcpPort.isSome():
+    conf.tcpPort = tcpPort.get()
+
+  if websocketPort.isSome():
+    conf.websocketPort = websocketPort.get()
+
+  # Rebuild NetConfig with bound port values
+  let netConf = networkConfiguration(conf, clientId).valueOr:
+    return err("Could not update NetConfig: " & error)
+
+  app.netConf = netConf
+
+  return ok()
+
+proc updateEnr(app: var App): AppResult[void] =
+
+  let record = enrConfiguration(app.conf, app.netConf, app.key).valueOr:
+    return err(error)
+
+  app.record = record
+  app.node.enr = record
+
+  if app.conf.discv5Discovery:
+    app.wakuDiscV5 = some(app.setupDiscoveryV5())
+
+  return ok()
+
+proc updateApp(app: var App): AppResult[void] =
+
+  if app.conf.tcpPort == Port(0) or app.conf.websocketPort == Port(0):
+
+    updateNetConfig(app).isOkOr:
+      return err("error calling updateNetConfig: " & $error)
+
+    updateEnr(app).isOkOr:
+      return err("error calling updateEnr: " & $error)
+
+    app.node.announcedAddresses = app.netConf.announcedAddresses
+
+    printNodeNetworkInfo(app.node)
+
+  return ok()
 
 ## Mount protocols
 
@@ -548,7 +585,18 @@ proc startNode(node: WakuNode, conf: WakuNodeConf,
 
   return ok()
 
-proc startApp*(app: App): Future[AppResult[void]] {.async.} =
+proc startApp*(app: var App): AppResult[void] =
+
+  try:
+    (waitFor startNode(app.node,app.conf,app.dynamicBootstrapNodes)).isOkOr:
+      return err(error)
+  except CatchableError:
+    return err("exception starting node: " & getCurrentExceptionMsg())
+
+  # Update app data that is set dynamically on node start
+  app.updateApp().isOkOr:
+    return err("Error in updateApp: " & $error)
+
   if app.wakuDiscv5.isSome():
     let wakuDiscv5 = app.wakuDiscv5.get()
 
@@ -559,11 +607,8 @@ proc startApp*(app: App): Future[AppResult[void]] {.async.} =
     asyncSpawn wakuDiscv5.searchLoop(app.node.peerManager)
     asyncSpawn wakuDiscv5.subscriptionsListener(app.node.topicSubscriptionQueue)
 
-  return await startNode(
-    app.node,
-    app.conf,
-    app.dynamicBootstrapNodes
-  )
+  return ok()
+
 
 
 ## Monitoring and external interfaces

apps/wakunode2/internal_config.nim

@@ -4,15 +4,61 @@ import
   libp2p/crypto/crypto,
   libp2p/multiaddress,
   libp2p/nameresolving/dnsresolver,
-  std/options,
+  std/[options, sequtils],
   stew/results,
   stew/shims/net
 import
   ../../waku/common/utils/nat,
   ../../waku/node/config,
   ../../waku/waku_enr/capabilities,
+  ../../waku/waku_enr,
+  ../../waku/waku_core,
   ./external_config
 
+proc enrConfiguration*(conf: WakuNodeConf, netConfig: NetConfig, key: crypto.PrivateKey):
+                      Result[enr.Record, string] =
+
+  var enrBuilder = EnrBuilder.init(key)
+
+  enrBuilder.withIpAddressAndPorts(
+    netConfig.enrIp,
+    netConfig.enrPort,
+    netConfig.discv5UdpPort
+  )
+
+  if netConfig.wakuFlags.isSome():
+    enrBuilder.withWakuCapabilities(netConfig.wakuFlags.get())
+
+  enrBuilder.withMultiaddrs(netConfig.enrMultiaddrs)
+
+  let topics =
+    if conf.pubsubTopics.len > 0 or conf.contentTopics.len > 0:
+      let shardsRes = conf.contentTopics.mapIt(getShard(it))
+      for res in shardsRes:
+        if res.isErr():
+          error "failed to shard content topic", error=res.error
+          return err($res.error)
+
+      let shards = shardsRes.mapIt(it.get())
+
+      conf.pubsubTopics & shards
+    else:
+      conf.topics
+
+  let addShardedTopics = enrBuilder.withShardedTopics(topics)
+  if addShardedTopics.isErr():
+      error "failed to add sharded topics to ENR", error=addShardedTopics.error
+      return err($addShardedTopics.error)
+
+  let recordRes = enrBuilder.build()
+  let record =
+    if recordRes.isErr():
+      error "failed to create record", error=recordRes.error
+      return err($recordRes.error)
+    else: recordRes.get()
+
+  return ok(record)
+
 proc validateExtMultiAddrs*(vals: seq[string]):
                             Result[seq[MultiAddress], string] =
   var multiaddrs: seq[MultiAddress]

apps/wakunode2/wakunode2.nim

@@ -87,7 +87,7 @@ when isMainModule:
 
   debug "5/7 Starting node and mounted protocols"
 
-  let res6 = waitFor wakunode2.startApp()
+  let res6 = wakunode2.startApp()
   if res6.isErr():
     error "5/7 Starting node and protocols failed", error=res6.error
     quit(QuitFailure)

tests/wakunode2/test_app.nim

@@ -12,7 +12,9 @@ import
 import
   ../testlib/common,
   ../testlib/wakucore,
-  ../testlib/wakunode,
+  ../testlib/wakunode
+
+include
   ../../apps/wakunode2/app
 
 suite "Wakunode2 - App":
@@ -27,7 +29,7 @@ suite "Wakunode2 - App":
 
     ## Then
     check:
-      version == app.git_version
+      version == git_version
 
 suite "Wakunode2 - App initialization":
   test "peer persistence setup should be successfully mounted":
@@ -53,7 +55,7 @@ suite "Wakunode2 - App initialization":
     require wakunode2.setupDyamicBootstrapNodes().isOk()
     require wakunode2.setupWakuApp().isOk()
     require isOk(waitFor wakunode2.setupAndMountProtocols())
-    require isOk(waitFor wakunode2.startApp())
+    require isOk(wakunode2.startApp())
     require wakunode2.setupMonitoringAndExternalInterfaces().isOk()
 
     ## Then
@@ -67,3 +69,43 @@ suite "Wakunode2 - App initialization":
 
     ## Cleanup
     waitFor wakunode2.stop()
+
+  test "app properly handles dynamic port configuration":
+    ## Given
+    var conf = defaultTestWakuNodeConf()
+    conf.tcpPort = Port(0)
+
+    ## When
+    var wakunode2 = App.init(rng(), conf)
+    require wakunode2.setupPeerPersistence().isOk()
+    require wakunode2.setupDyamicBootstrapNodes().isOk()
+    require wakunode2.setupWakuApp().isOk()
+    require isOk(waitFor wakunode2.setupAndMountProtocols())
+    require isOk(wakunode2.startApp())
+    require wakunode2.setupMonitoringAndExternalInterfaces().isOk()
+
+    ## Then
+    let 
+      node = wakunode2.node
+      typedNodeEnr = node.enr.toTypedRecord()
+      typedAppEnr = wakunode2.record.toTypedRecord()
+
+    assert typedNodeEnr.isOk(), $typedNodeEnr.error
+    assert typedAppEnr.isOk(), $typedAppEnr.error
+
+    check:
+      # App started properly
+      not node.isNil()
+      node.wakuArchive.isNil()
+      node.wakuStore.isNil()
+      not node.wakuStoreClient.isNil()
+      not node.rendezvous.isNil()
+
+      # DS structures are updated with dynamic ports
+      wakunode2.netConf.bindPort != Port(0)
+      wakunode2.netConf.enrPort.get() != Port(0)
+      typedNodeEnr.get().tcp.get() != 0
+      typedAppEnr.get().tcp.get() != 0
+
+    ## Cleanup
+    waitFor wakunode2.stop()

waku/node/config.nim

@@ -59,7 +59,7 @@ proc formatListenAddress(inputMultiAdd: MultiAddress): MultiAddress =
     # If MultiAddress contains "0.0.0.0", replace it for "127.0.0.1"
     return MultiAddress.init(inputStr.replace("0.0.0.0", "127.0.0.1")).get()
 
-proc isWsAddress(ma: MultiAddress): bool =
+proc isWsAddress*(ma: MultiAddress): bool =
   let
     isWs = ma.contains(multiCodec("ws")).get()
     isWss = ma.contains(multiCodec("wss")).get()

waku/node/waku_node.nim

@@ -1073,6 +1073,26 @@ proc mountRendezvous*(node: WakuNode) {.async, raises: [Defect, LPError].} =
 
   node.switch.mount(node.rendezvous)
 
+proc isBindIpWithZeroPort(inputMultiAdd: MultiAddress): bool =
+  let inputStr = $inputMultiAdd
+  if inputStr.contains("0.0.0.0/tcp/0") or inputStr.contains("127.0.0.1/tcp/0"):
+    return true
+
+  return false
+
+proc printNodeNetworkInfo*(node: WakuNode): void =
+  let peerInfo = node.switch.peerInfo
+  var listenStr = ""
+
+  info "PeerInfo", peerId = peerInfo.peerId, addrs = peerInfo.addrs
+
+  for address in node.announcedAddresses:
+    var fulladdr = "[" & $address & "/p2p/" & $peerInfo.peerId & "]"
+    listenStr &= fulladdr
+
+  ## XXX: this should be /ip4..., / stripped?
+  info "Listening on", full = listenStr
+  info "DNS: discoverable ENR ", enr = node.enr.toUri()
 
 proc start*(node: WakuNode) {.async.} =
   ## Starts a created Waku Node and
@@ -1081,16 +1101,15 @@ proc start*(node: WakuNode) {.async.} =
   waku_version.set(1, labelValues=[git_version])
   info "Starting Waku node", version=git_version
 
-  let peerInfo = node.switch.peerInfo
-  info "PeerInfo", peerId = peerInfo.peerId, addrs = peerInfo.addrs
-  var listenStr = ""
+  var zeroPortPresent = false
   for address in node.announcedAddresses:
-    var fulladdr = "[" & $address & "/p2p/" & $peerInfo.peerId & "]"
-    listenStr &= fulladdr
+    if isBindIpWithZeroPort(address):
+      zeroPortPresent = true
 
-  ## XXX: this should be /ip4..., / stripped?
-  info "Listening on", full = listenStr
-  info "DNS: discoverable ENR ", enr = node.enr.toUri()
+  if not zeroPortPresent:
+    printNodeNetworkInfo(node)
+  else:
+    info "Listening port is dynamically allocated, address and ENR generation postponed"
 
   # Perform relay-specific startup tasks TODO: this should be rethought
   if not node.wakuRelay.isNil():