iPhone Swift gRPC 客户端从 Windows C# gRPC 服务器获得“连接被拒绝”

Question

I have a gRPC server written in C# running in Windows 10. I can connect to it and invoke services with a C# gRPC client on the same PC, but when I try to connect from an iPhone running a simple client in Swift, the app reports

2021-02-12 12:28:48.639854-0800 grpc-Swift[53758:732067] [connection] nw_socket_handle_socket_event [C5:1] Socket SO_ERROR [61: Connection refused]

当我在 Windows PC 上的同一端口上运行手机时，我能够从手机连接到 Golang 服务器，因此这不是布线或防火墙问题。 我错过了什么？？

.proto 文件

syntax = "proto3";
package chat;

option go_package = "github.com/monkrus/grpc-from0;grpc_from0";

message Message{
    string body = 1;
}

service ChatService{
    rpc SayHello(Message) returns (Message) {}
}

c# 服务器：

using System.Threading.Tasks;
using Chat;
using Grpc.Core;

namespace ChatServer {

    public class ChatServiceImpl : ChatService.ChatServiceBase {
        public override Task<Message> SayHello( Message request, ServerCallContext context ) {
            Message reply = new Message { Body = "Got it!" };
            return Task.FromResult( reply );
        }
    }

    class Program {
        static int port = 2319;

        static void Main( string[] args ) {
            Console.WriteLine( $"Starting Chat Server on port {port}" );
            Server server = new Server {
                Services = { ChatService.BindService( new ChatServiceImpl() ) },
                Ports = { new ServerPort( "localhost", port, ServerCredentials.Insecure ) }
            };
            server.Start();
            Console.WriteLine( "Server started.  Press any key to exit." );
            Console.ReadKey();
            server.ShutdownAsync().Wait();
        }
    }
}

iPhone客户端ViewController.swift：

import UIKit
import GRPC

class ViewController: UIViewController {

    var client:Chat_ChatServiceClient?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupConnection()
    }
    
    func setupConnection(){
        let eventGroup = PlatformSupport.makeEventLoopGroup(loopCount: 1)
        let channel = ClientConnection.insecure(group: eventGroup).connect(host:
            "192.168.86.44", port: 2319 )
        self.client = Chat_ChatServiceClient(channel: channel)
    }
    
    @IBAction func sendMessage(){
        createMessage()
    }
    
    func createMessage(){
        var message = Chat_Message()
        message.body = "Hello from swift"
        let x = client?.sayHello(message).response
        x?.whenSuccess({ (message) in print("response from server: \(message.body)") })
    }
}

在 Windows 上运行的 golang 服务器：

package main

import (
    "log"
    "net"
    "fmt"
    "go-grpc-tutorial/chat"
    "google.golang.org/grpc"
)

func main() {
    fmt.Println( "Listening on port 2319..." )
    lis, err := net.Listen("tcp", ":2319")
    if err != nil {
        log.Fatalf("Failed to listen on port 2319: %v", err)
    }

    s := chat.Server{}
    grpcServer := grpc.NewServer()
    chat.RegisterChatServiceServer(grpcServer, &s)

    if err := grpcServer.Serve(lis); err != nil {
        log.Fatalf("Failed to serve grpc server over port 2319: %v", err)
    }
}

Answer 1

找到了！ 我将服务器初始化从

Ports = { new ServerPort( "localhost", port, ServerCredentials.Insecure )

至

Ports = { new ServerPort( "0.0.0.0", port, ServerCredentials.Insecure )

并且所有工作都按预期进行。

如果我在客户端网络上使用服务器的 IP 地址 - 即“192.168.86.44”，它也可以工作。 很想听听这个数字是如何解释的——如果“localhost”是一个与客户端不同的网络？ 如果“0.0.0.0”只是一个通配符......？