使用golang客户端的GRPC Web请求？

我正在尝试使用grpc web包装器的hep创建grpc服务器。其想法是将此grpc服务器与基于浏览器的应用程序以及普通grpc客户端一起使用。但我很困惑，如何才能使它同时适用于这两种应用程序

package main

import (
    "context"
    "fmt"
    "io"
    "log"
    "net/http"
    "strconv"
    "time"

    "github.com/repo/test-grpc-server/greet/greetpb"
    "github.com/improbable-eng/grpc-web/go/grpcweb"
    "google.golang.org/grpc"
)

type server struct{}

func (*server) Greet(ctx context.Context, req *greetpb.GreetRequest) (*greetpb.GreetResponse, error) {
    fmt.Printf("Greet function was invoked with %v", req)
    firstName := req.GetGreeting().GetFirstName()
    result := "Hello " + firstName
    res := greetpb.GreetResponse{
        Result: result,
    }
    return &res, nil
}

func (*server) GreetManyTimes(req *greetpb.GreetManyTimesRequest, stream greetpb.GreetService_GreetManyTimesServer) error {
    fmt.Printf("GreetMany function was invoked with %v", req)

    firstName := req.GetGreeting().GetFirstName()

    for i := 0; i < 10; i++ {
        result := "Hello " + firstName + " number " + strconv.Itoa(i)
        res := &greetpb.GreetManyTimesResponse{
            Result: result,
        }
        stream.Send(res)
        time.Sleep(1000 * time.Millisecond)
    }
    return nil

}
func (*server) LongGreet(stream greetpb.GreetService_LongGreetServer) error {
    fmt.Printf("LongGreet function was invoked with a streaming request\n")
    result := ""
    for {
        req, err := stream.Recv()
        if err == io.EOF {
            // we have finished reading the client stream
            return stream.SendAndClose(&greetpb.LongGreetResponse{
                Result: result,
            })
        }
        if err != nil {
            log.Fatalf("Error while reading client stream: %v", err)
        }

        firstName := req.GetGreeting().GetFirstName()
        result += "Hello " + firstName + "! "
    }
}



func main() {
    fmt.Println("Go gRPC Server")
    /*lis, err := net.Listen("tcp", ":5051")
    if err != nil {
        log.Fatalf("Failed to listen: %v", err)
    }*/
    grpcServer := grpc.NewServer()
    greetpb.RegisterGreetServiceServer(grpcServer, &server{})
    grpc := grpcweb.WrapServer(grpcServer)
    http.HandleFunc("/", func(resp http.ResponseWriter, req *http.Request) {
        allowCors(resp, req)
        if grpc.IsGrpcWebRequest(req) || grpc.IsAcceptableGrpcCorsRequest(req) {
            grpc.ServeHTTP(resp, req)
        }
    })
    httpPort := ":50051"
    fmt.Println("HTTP server listening on", httpPort)
    err := http.ListenAndServe(httpPort, nil)
    if err != nil {
        log.Fatal("Failed to start a HTTP server:", err)
    }

}

func allowCors(resp http.ResponseWriter, req *http.Request) {
    resp.Header().Set("Access-Control-Allow-Origin", "*")
    resp.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
    resp.Header().Set("Access-Control-Expose-Headers", "grpc-status, grpc-message")
    resp.Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, XMLHttpRequest, x-user-agent, x-grpc-web, grpc-status, grpc-message")
}

我的.prot文件如下所示

syntax = "proto3";

package greet;
option go_package="./greet/greetpb";

message Greeting {
    string first_name =1 ;
    string last_name = 2;
}

message GreetRequest {
    Greeting greeting = 1;
}

message GreetResponse {
    string result = 1;
}

message GreetManyTimesRequest{
    Greeting greeting =1;
}

message GreetManyTimesResponse{
    string result=1;
}
message LongGreetRequest {
    Greeting greeting = 1;


}

message LongGreetResponse{
    string result = 1;
}


service GreetService{
    //Unary
    rpc Greet (GreetRequest) returns (GreetResponse) {};
    //Server Streaming 
    rpc GreetManyTimes(GreetManyTimesRequest) returns (stream GreetManyTimesResponse) {};
    //Client Streaming 
    rpc LongGreet(stream LongGreetRequest) returns (LongGreetResponse) {};

}

我得到的错误日志是

Hello I'm a client
INFO: 2021/04/27 12:53:17 [core] parsed scheme: ""
INFO: 2021/04/27 12:53:17 [core] scheme "" not registered, fallback to default scheme
INFO: 2021/04/27 12:53:17 [core] ccResolverWrapper: sending update to cc: {[{0.0.0.0:50051  <nil> 0 <nil>}] <nil> <nil>}
INFO: 2021/04/27 12:53:17 [core] ClientConn switching balancer to "pick_first"
INFO: 2021/04/27 12:53:17 [core] Channel switches to new LB policy "pick_first"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] parsed scheme: ""
INFO: 2021/04/27 12:53:17 [core] scheme "" not registered, fallback to default scheme
INFO: 2021/04/27 12:53:17 [core] ccResolverWrapper: sending update to cc: {[{0.0.0.0:50051  <nil> 0 <nil>}] <nil> <nil>}
INFO: 2021/04/27 12:53:17 [core] ClientConn switching balancer to "pick_first"
INFO: 2021/04/27 12:53:17 [core] Channel switches to new LB policy "pick_first"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to CONNECTING
do unary from the client
INFO: 2021/04/27 12:53:17 [core] blockingPicker: the picked transport is not ready, loop back to repick
INFO: 2021/04/27 12:53:17 [core] Subchannel picks a new address "0.0.0.0:50051" to connect
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021cd0, {CONNECTING <nil>}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] Subchannel picks a new address "0.0.0.0:50051" to connect
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021ed0, {CONNECTING <nil>}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [transport] transport: loopyWriter.run returning. connection error: desc = "transport is closing"
INFO: 2021/04/27 12:53:17 [transport] transport: loopyWriter.run returning. connection error: desc = "transport is closing"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021ed0, {TRANSIENT_FAILURE connection closed}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021cd0, {TRANSIENT_FAILURE connection closed}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to TRANSIENT_FAILURE
2021/04/27 12:53:17 error while calling Greet RPC: rpc error: code = Unavailable desc = connection closed
exit status 1

你好，我是客户
信息：2021/04/27 12:53:17[核心]解析方案：“
信息：2021/04/27 12:53:17[核心]方案“”未注册，回退到默认方案
信息：2021/04/27 12:53:17[core]ccresolverrapper:将更新发送到cc:{[{0.0.0.0:50051 0}]}
信息：2021/04/27 12:53:17[核心]客户端连接将平衡器切换为“先选择”
信息：2021/04/27 12:53:17[核心]频道切换到新的LB策略“优先选择”
信息：2021/04/27 12:53:17[核心]子通道连接更改为连接
信息：2021/04/27 12:53:17[核心]解析方案：“
信息：2021/04/27 12:53:17[核心]方案“”未注册，回退到默认方案
信息：2021/04/27 12:53:17[core]ccresolverrapper:将更新发送到cc:{[{0.0.0.0:50051 0}]}
信息：2021/04/27 12:53:17[核心]客户端连接将平衡器切换为“先选择”
信息：2021/04/27 12:53:17[核心]频道切换到新的LB策略“优先选择”
信息：2021/04/27 12:53:17[核心]子通道连接更改为连接
从客户那里得到一元钱
信息：2021/04/27 12:53:17[核心]阻止拾取程序：拾取的传输尚未就绪，请返回到repick
信息：2021/04/27 12:53:17[核心]子频道选择一个新地址“0.0.0.0:50051”进行连接
信息：2021/04/27 12:53:17[核心]pickfirstBalancer:UpdateSubConnState:0xc000021cd0，{CONNECTING}
信息：2021/04/27 12:53:17[核心]通道连接更改为连接
信息：2021/04/27 12:53:17[核心]子频道选择一个新地址“0.0.0.0:50051”进行连接
信息：2021/04/27 12:53:17[核心]pickfirstBalancer:UpdateSubConnState:0xc000021ed0，{CONNECTING}
信息：2021/04/27 12:53:17[核心]通道连接更改为连接
信息：2021/04/27 12:53:17[核心]子信道连接更改为瞬态故障
信息：2021/04/27 12:53:17[传输]传输：loopyWriter.run返回。连接错误：desc=“传输正在关闭”
信息：2021/04/27 12:53:17[传输]传输：loopyWriter.run返回。连接错误：desc=“传输正在关闭”
信息：2021/04/27 12:53:17[核心]子信道连接更改为瞬态故障
信息：2021/04/27 12:53:17[核心]pickfirstBalancer:UpdateSubConnState:0xc000021ed0，{TRANSIENT_FAILURE connection closed}
信息：2021/04/27 12:53:17[核心]通道连接更改为瞬时故障
信息：2021/04/27 12:53:17[核心]pickfirstBalancer:UpdateSubConnState:0xc000021cd0，{TRANSIENT_FAILURE connection closed}
信息：2021/04/27 12:53:17[核心]通道连接更改为瞬时故障
2021/04/27 12:53:17调用RPC时出错：RPC错误：代码=不可用描述=连接已关闭
退出状态1

---

如果有人能帮上忙，我将不胜感激。谢谢大家!

根据评论，问题是您正试图使用gRPC客户端连接到gRPC Web服务器。gRPC和gRPC Web是不同的有线协议（创建gRPC Web是因为Web浏览器API不能对实现gRPC的HTTP/2请求提供足够的控制）。提供了一个很好的概述

因为您正在构建一个web应用程序，所以需要使用gRPC web；如果您还希望使用go客户端连接到您的服务器，那么首选选项是使用gRPC（服务器可以同时使用两者）。另一个可行的选择是使用a，但我没有尝试过（这样会降低效率）

运行gRPC Web的“官方”方式是通过代理，但当您在Go中编写此内容时，它提供了另一个更简单的选项，您已经在使用该选项（他们也有代理，但这使部署更加复杂）

您的服务器需要更改以同时运行gRPC和gRPC Web。最简单的选择是在不同的端口上运行它们（可能可以使用mux来检测内容类型，但这不是我尝试过的；如果您愿意，它可以很好地工作）

我运行这两台服务器的方法如下（请将其视为不完整的伪代码，我已经从我的一些应用程序中提取了位，但尚未编译/测试等；发现问题时请随时更新！）：

grpcServer:=grpc.NewServer（）
greetpb.RegisterGreetServiceServer（grpcServer，&server{}）
//您的应用程序可能正在做其他事情，您希望
//能够干净地关机；在上下文中传递是一种很好的方法。。
ctx，cancel=context.cancel（context.Background（））
defer cancel（）//确保最终调用cancel函数
//在端口50050上启动grpc服务器
grpcTerminated:=make（chan结构{}）
lis，err:=net.Listen（“tcp”，“50050”）
如果出错！=零{
恐慌（fmt.Sprintf（“gRPC-未能侦听：%s”，错误））
}
go func（）{
如果sErr:=grpcServer.service（lis）；sErr！=nil{
fmt.Printf（“grpc服务器关闭：%s”，错误）
}
close（grpcTerminated）//如果服务器在没有我们请求的情况下被终止
}()
//在端口5051上启动grpc Web服务器
grpcWebTerminated:=make（chan结构{}）
grpc:=grpcweb.WrapServer（grpcServer）
mux:=http.NewServeMux（）
mux.HandleFunc（“/”，func（resp http.ResponseWriter，req*http.Request）{
允许（响应、要求）
如果grpc.IsGrpcWebRequest（req）| | grpc.IsAcceptableGrpcCorsRequest（req）{
grpc.维修TTP（相应要求）
}
}))
rpcWebServer:=&http.Server{
处理器：多路复用器，
地址：“：50051”}
工作组.添加（1）
go func（）{
推迟工作组完成（）
如果错误：=rpcWebServer.ListenAndServe（）；错误！=nil{
fmt.Printf（“Web服务器（GRPC）关闭：%s”，错误）
}
关闭（grpcWebTerminated）//如果服务器在没有我们请求的情况下终止
}()
//等待web服务器关闭或上下文取消。。。
挑选{
案例尝试使用以下内容：
conn，err:=grpc.Dial（“localhost:50051”，grpc.withunsecure（））
Hello I'm a client
INFO: 2021/04/27 12:53:17 [core] parsed scheme: ""
INFO: 2021/04/27 12:53:17 [core] scheme "" not registered, fallback to default scheme
INFO: 2021/04/27 12:53:17 [core] ccResolverWrapper: sending update to cc: {[{0.0.0.0:50051  <nil> 0 <nil>}] <nil> <nil>}
INFO: 2021/04/27 12:53:17 [core] ClientConn switching balancer to "pick_first"
INFO: 2021/04/27 12:53:17 [core] Channel switches to new LB policy "pick_first"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] parsed scheme: ""
INFO: 2021/04/27 12:53:17 [core] scheme "" not registered, fallback to default scheme
INFO: 2021/04/27 12:53:17 [core] ccResolverWrapper: sending update to cc: {[{0.0.0.0:50051  <nil> 0 <nil>}] <nil> <nil>}
INFO: 2021/04/27 12:53:17 [core] ClientConn switching balancer to "pick_first"
INFO: 2021/04/27 12:53:17 [core] Channel switches to new LB policy "pick_first"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to CONNECTING
do unary from the client
INFO: 2021/04/27 12:53:17 [core] blockingPicker: the picked transport is not ready, loop back to repick
INFO: 2021/04/27 12:53:17 [core] Subchannel picks a new address "0.0.0.0:50051" to connect
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021cd0, {CONNECTING <nil>}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] Subchannel picks a new address "0.0.0.0:50051" to connect
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021ed0, {CONNECTING <nil>}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to CONNECTING
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [transport] transport: loopyWriter.run returning. connection error: desc = "transport is closing"
INFO: 2021/04/27 12:53:17 [transport] transport: loopyWriter.run returning. connection error: desc = "transport is closing"
INFO: 2021/04/27 12:53:17 [core] Subchannel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021ed0, {TRANSIENT_FAILURE connection closed}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to TRANSIENT_FAILURE
INFO: 2021/04/27 12:53:17 [core] pickfirstBalancer: UpdateSubConnState: 0xc000021cd0, {TRANSIENT_FAILURE connection closed}
INFO: 2021/04/27 12:53:17 [core] Channel Connectivity change to TRANSIENT_FAILURE
2021/04/27 12:53:17 error while calling Greet RPC: rpc error: code = Unavailable desc = connection closed
exit status 1