Detailed port-in-use error

src/Nethermind/Nethermind.Config/ConfigExtensions.cs

@@ -2,12 +2,35 @@
 // SPDX-License-Identifier: LGPL-3.0-only
 
 using System;
+using System.Collections.Concurrent;
 using System.ComponentModel;
+using System.Linq;
 using System.Reflection;
 
 namespace Nethermind.Config;
 public static class ConfigExtensions
 {
+    private static readonly ConcurrentDictionary<string, bool> PortOptions = new();
+
+    public static string GetCategoryName(Type type)
+    {
+        if (type.IsAssignableTo(typeof(INoCategoryConfig)))
+            return null;
+
+        string categoryName = type.Name.RemoveEnd("Config");
+        if (type.IsInterface) categoryName = categoryName.RemoveStart('I');
+        return categoryName;
+    }
+
+    public static void AddPortOptionName(Type categoryType, string optionName) =>
+        PortOptions.TryAdd(
+            GetCategoryName(categoryType) is { } categoryName ? $"{categoryName}.{optionName}" : optionName,
+            true
+        );
+
+    public static string[] GetPortOptionNames() =>
+        PortOptions.Keys.OrderByDescending(x => x).ToArray();
+
     public static T GetDefaultValue<T>(this IConfig config, string propertyName)
     {
         Type type = config.GetType();

src/Nethermind/Nethermind.Config/ConfigItemAttribute.cs

@@ -16,5 +16,7 @@ public class ConfigItemAttribute : Attribute
         public bool DisabledForCli { get; set; }
 
         public string EnvironmentVariable { get; set; }
+
+        public bool IsPortOption { get; set; }
     }
 }

src/Nethermind/Nethermind.Config/StringExtensions.cs

@@ -15,6 +15,9 @@ public static string RemoveStart(this string thisString, char removeChar) =>
         public static string RemoveEnd(this string thisString, char removeChar) =>
             thisString.EndsWith(removeChar) ? thisString[..^1] : thisString;
 
+        public static string RemoveEnd(this string thisString, string removeString) =>
+            thisString.EndsWith(removeString) ? thisString[..^removeString.Length] : thisString;
+
         public static bool Contains(this IEnumerable<string> collection, string value, StringComparison comparison) =>
             collection.Any(i => string.Equals(i, value, comparison));
     }

src/Nethermind/Nethermind.Grpc/IGrpcConfig.cs

@@ -14,7 +14,7 @@ public interface IGrpcConfig : IConfig
         [ConfigItem(Description = "An address of the host under which gRPC will be running", DefaultValue = "localhost")]
         string Host { get; }
 
-        [ConfigItem(Description = "Port of the host under which gRPC will be exposed", DefaultValue = "50000")]
+        [ConfigItem(Description = "Port of the host under which gRPC will be exposed", DefaultValue = "50000", IsPortOption = true)]
         int Port { get; }
     }
 }

src/Nethermind/Nethermind.JsonRpc/IJsonRpcConfig.cs

@@ -43,10 +43,10 @@ public interface IJsonRpcConfig : IConfig
     [ConfigItem(Description = "The diagnostic recording mode.", DefaultValue = "None")]
     RpcRecorderState RpcRecorderState { get; set; }
 
-    [ConfigItem(Description = "The JSON-RPC service HTTP port.", DefaultValue = "8545")]
+    [ConfigItem(Description = "The JSON-RPC service HTTP port.", DefaultValue = "8545", IsPortOption = true)]
     int Port { get; set; }
 
-    [ConfigItem(Description = "The JSON-RPC service WebSockets port.", DefaultValue = "8545")]
+    [ConfigItem(Description = "The JSON-RPC service WebSockets port.", DefaultValue = "8545", IsPortOption = true)]
     int WebSocketsPort { get; set; }
 
     [ConfigItem(Description = "The path to connect a UNIX domain socket over.")]
@@ -147,7 +147,7 @@ public interface IJsonRpcConfig : IConfig
     [ConfigItem(Description = "The Engine API host.", DefaultValue = "127.0.0.1")]
     string EngineHost { get; set; }
 
-    [ConfigItem(Description = "The Engine API port.", DefaultValue = "null")]
+    [ConfigItem(Description = "The Engine API port.", DefaultValue = "null", IsPortOption = true)]
     int? EnginePort { get; set; }
 
     [ConfigItem(

src/Nethermind/Nethermind.Network.Discovery/DiscoveryConnectionsPool.cs

@@ -32,7 +32,9 @@ public DiscoveryConnectionsPool(ILogger logger, INetworkConfig networkConfig, ID
     public async Task<IChannel> BindAsync(Bootstrap bootstrap, int port)
     {
         if (_byPort.TryGetValue(port, out Task<IChannel>? task)) return await task;
-        _byPort.Add(port, task = bootstrap.BindAsync(_ip, port));
+
+        task = NetworkHelper.HandlePortTakenError(() => bootstrap.BindAsync(_ip, port), port);
+        _byPort.Add(port, task);
 
         return await task.ContinueWith(t =>
         {

src/Nethermind/Nethermind.Network.Discovery/Discv5/DiscoveryV5App.cs

@@ -98,7 +98,7 @@ .. _discoveryDb.GetAllValues().Select(enr => enrFactory.CreateFromBytes(enr, ide
                 NettyDiscoveryV5Handler.Register(s);
             });
 
-        _discv5Protocol = discv5Builder.Build();
+        _discv5Protocol = NetworkHelper.HandlePortTakenError(discv5Builder.Build, networkConfig.DiscoveryPort);
         _discv5Protocol.NodeAdded += (e) => NodeAddedByDiscovery(e.Record);
         _discv5Protocol.NodeRemoved += NodeRemovedByDiscovery;
 

src/Nethermind/Nethermind.Network/Config/INetworkConfig.cs

@@ -47,10 +47,10 @@ public interface INetworkConfig : IConfig
     [ConfigItem(DisabledForCli = true, HiddenFromDocs = true, DefaultValue = "10000")]
     int P2PPingInterval { get; }
 
-    [ConfigItem(Description = $"The UDP port number for incoming discovery connections. It's recommended to keep it the same as the TCP port (`{nameof(P2PPort)}`) because other values have not been tested yet.", DefaultValue = "30303")]
+    [ConfigItem(Description = $"The UDP port number for incoming discovery connections. It's recommended to keep it the same as the TCP port (`{nameof(P2PPort)}`) because other values have not been tested yet.", DefaultValue = "30303", IsPortOption = true)]
     int DiscoveryPort { get; set; }
 
-    [ConfigItem(Description = "The TCP port for incoming P2P connections.", DefaultValue = "30303")]
+    [ConfigItem(Description = "The TCP port for incoming P2P connections.", DefaultValue = "30303", IsPortOption = true)]
     int P2PPort { get; set; }
 
     [ConfigItem(DisabledForCli = true, HiddenFromDocs = true, DefaultValue = "2000")]

src/Nethermind/Nethermind.Network/NetworkHelper.cs

@@ -0,0 +1,78 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using System;
+using System.IO;
+using System.Net.Sockets;
+using System.Runtime.ExceptionServices;
+using System.Threading.Tasks;
+
+namespace Nethermind.Network;
+
+public static class NetworkHelper
+{
+    private static PortInUseException MapOrRethrow(Exception exception, int[]? ports = null, string[]? urls = null)
+    {
+        if (exception is AggregateException)
+            exception = exception.InnerException!;
+
+        switch (exception)
+        {
+            case SocketException { SocketErrorCode: SocketError.AddressAlreadyInUse or SocketError.AccessDenied }:
+                return ports != null ? new(exception, ports) : new(exception, urls!);
+            case IOException { Source: "Grpc.Core" } when exception.Message.Contains("Failed to bind port"):
+                return ports != null ? new(exception, ports) : new(exception, urls!);
+            default:
+                ExceptionDispatchInfo.Throw(exception);
+                throw exception; // Make compiler happy, should never execute
+        }
+    }
+
+    public static void HandlePortTakenError(Action action, params int[] ports)
+    {
+        try
+        {
+            action();
+        }
+        catch (Exception exception)
+        {
+            throw MapOrRethrow(exception, ports: ports);
+        }
+    }
+
+    public static T HandlePortTakenError<T>(Func<T> action, params int[] ports)
+    {
+        try
+        {
+            return action();
+        }
+        catch (Exception exception)
+        {
+            throw MapOrRethrow(exception, ports: ports);
+        }
+    }
+
+    public static async Task HandlePortTakenError(Func<Task> action, params string[] urls)
+    {
+        try
+        {
+            await action();
+        }
+        catch (Exception exception)
+        {
+            throw MapOrRethrow(exception, urls: urls);
+        }
+    }
+
+    public static async Task<T> HandlePortTakenError<T>(Func<Task<T>> action, params int[] ports)
+    {
+        try
+        {
+            return await action();
+        }
+        catch (Exception exception)
+        {
+            throw MapOrRethrow(exception, ports: ports);
+        }
+    }
+}

src/Nethermind/Nethermind.Network/PortInUseException.cs

@@ -0,0 +1,34 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using System;
+using System.IO;
+using System.Linq;
+using Nethermind.Config;
+
+namespace Nethermind.Network;
+
+public class PortInUseException : IOException
+{
+    public PortInUseException(Exception exception, params int[] ports) : base(
+        $"{GetReason(ports)} " +
+        "If you intend to run 2 or more nodes on one machine, ensure you have changed all configured ports under: " +
+        $"{"\n\t" + string.Join("\n\t", ConfigExtensions.GetPortOptionNames())}",
+        exception
+    )
+    { }
+
+    public PortInUseException(Exception exception, params string[] urls) : this(exception, GetPorts(urls)) { }
+
+    private static int[] GetPorts(string[] urls) => urls.Select(u => new Uri(u).Port).ToArray();
+
+    private static string GetReason(params int[] ports)
+    {
+        return ports.Length switch
+        {
+            0 => "One of the configured ports is in use.",
+            1 => $"Port {ports[0]} is in use.",
+            _ => $"One or more of the ports {string.Join(',', ports)} are in use."
+        };
+    }
+}

src/Nethermind/Nethermind.Network/Rlpx/RlpxHost.cs

@@ -131,25 +131,16 @@ public async Task Init()
                         InitializeChannel(ch, session);
                     }));
 
-                Task<IChannel> openTask = LocalIp is null
-                    ? bootstrap.BindAsync(LocalPort)
-                    : bootstrap.BindAsync(IPAddress.Parse(LocalIp), LocalPort);
+                Task<IChannel> openTask = NetworkHelper.HandlePortTakenError(() => LocalIp is null
+                        ? bootstrap.BindAsync(LocalPort)
+                        : bootstrap.BindAsync(IPAddress.Parse(LocalIp), LocalPort),
+                    LocalPort);
 
                 _bootstrapChannel = await openTask.ContinueWith(t =>
                 {
                     if (t.IsFaulted)
                     {
-                        AggregateException aggregateException = t.Exception;
-                        if (aggregateException?.InnerException is SocketException socketException
-                            && socketException.ErrorCode == 10048)
-                        {
-                            if (_logger.IsError) _logger.Error($"Port {LocalPort} is in use. You can change the port used by adding: --{nameof(NetworkConfig).Replace("Config", string.Empty)}.{nameof(NetworkConfig.P2PPort)} 30303");
-                        }
-                        else
-                        {
-                            if (_logger.IsError) _logger.Error($"{nameof(Init)} failed", t.Exception);
-                        }
-
+                        if (_logger.IsError) _logger.Error($"{nameof(Init)} failed", t.Exception);
                         return null;
                     }
 

src/Nethermind/Nethermind.Runner/Ethereum/GrpcRunner.cs

@@ -6,6 +6,7 @@
 using Grpc.Core;
 using Nethermind.Grpc;
 using Nethermind.Logging;
+using Nethermind.Network;
 
 namespace Nethermind.Runner.Ethereum
 {
@@ -30,7 +31,9 @@ public Task Start(CancellationToken cancellationToken)
                 Services = { NethermindService.BindService(_service) },
                 Ports = { new ServerPort(_config.Host, _config.Port, ServerCredentials.Insecure) }
             };
-            _server.Start();
+            NetworkHelper.HandlePortTakenError(
+                _server.Start, _config.Port
+            );
             if (_logger.IsInfo) _logger.Info($"Started GRPC server on {_config.Host}:{_config.Port}.");
 
             return Task.CompletedTask;

src/Nethermind/Nethermind.Runner/Ethereum/JsonRpcRunner.cs

@@ -16,6 +16,7 @@
 using Nethermind.Core.Authentication;
 using Nethermind.JsonRpc;
 using Nethermind.Logging;
+using Nethermind.Network;
 using Nethermind.Runner.JsonRpc;
 using Nethermind.Runner.Logging;
 using Nethermind.Sockets;
@@ -59,7 +60,7 @@ public JsonRpcRunner(
             _api = api;
         }
 
-        public Task Start(CancellationToken cancellationToken)
+        public async Task Start(CancellationToken cancellationToken)
         {
             if (_logger.IsDebug) _logger.Debug("Initializing JSON RPC");
             string[] urls = _jsonRpcUrlCollection.Urls;
@@ -95,11 +96,11 @@ public Task Start(CancellationToken cancellationToken)
 
             if (!cancellationToken.IsCancellationRequested)
             {
-                _webHost.Start();
+                await NetworkHelper.HandlePortTakenError(
+                    () => _webHost.StartAsync(cancellationToken), urls
+                );
                 if (_logger.IsDebug) _logger.Debug($"JSON RPC     : {urlsString}");
             }
-
-            return Task.CompletedTask;
         }
 
         public async Task StopAsync()

src/Nethermind/Nethermind.Runner/Program.cs

@@ -288,8 +288,11 @@ private static void BuildOptionsFromConfigFiles(CommandLineApplication app)
                 ConfigItemAttribute? configItemAttribute = propertyInfo.GetCustomAttribute<ConfigItemAttribute>();
                 if (!(configItemAttribute?.DisabledForCli ?? false))
                 {
-                    _ = app.Option($"--{configType.Name[1..].Replace("Config", string.Empty)}.{propertyInfo.Name}", $"{(configItemAttribute is null ? "<missing documentation>" : configItemAttribute.Description + $" (DEFAULT: {configItemAttribute.DefaultValue})" ?? "<missing documentation>")}", CommandOptionType.SingleValue);
-
+                    _ = app.Option($"--{ConfigExtensions.GetCategoryName(configType)}.{propertyInfo.Name}", $"{(configItemAttribute is null ? "<missing documentation>" : configItemAttribute.Description + $" (DEFAULT: {configItemAttribute.DefaultValue})" ?? "<missing documentation>")}", CommandOptionType.SingleValue);
+                }
+                if (configItemAttribute?.IsPortOption == true)
+                {
+                    ConfigExtensions.AddPortOptionName(configType, propertyInfo.Name);
                 }
             }
         }