AspNetCore中 使用 Grpc 简单Demo

为什么要用Grpc

跨语言进行，调用服务，获取跨服务器调用等

目前我的需要使用 我的抓取端是go 写的 查询端用 Net6 写的 导致很多时候 我需要把一些临时数据写入到 Redis 在两个服务器进行处理

参考地址：

哔哩哔哩杨旭大佬：https://www.bilibili.com/video/BV1eE411T7GC/?spm_id_from=333.999.0.0

强烈建议去看一遍杨旭大佬讲的这篇Grpc 没有那么繁琐 清晰明了

1、依赖安装：

Grpc.AspNetCore Server 端包

2、编写proto 文件

点击查看代码

syntax = "proto3";

option csharp_namespace= "GrpcServer.Web.Protos";

message Employee{
	int32 id = 1;
	int32 no = 2;
	string firstName = 3;
	string lastName =4;
	float salary = 5;

}

message GetByNoRequest{
	int32 no =1;
}

message EmployeeResponse{
	Employee employee =1;

}

message GetAllRequest{

}

message AddPhotoRequest{
	bytes data = 1;

}

message AddPhotoResponse{
	bool isOK = 1;
}

message EmployeeRequest{
	Employee employee = 1;
}

service EmployeeService {
	rpc GetByNo(GetByNoRequest) returns (EmployeeResponse);
	rpc GetAll(GetAllRequest) returns (stream EmployeeResponse);
	rpc AddPhoto(stream AddPhotoRequest) returns (AddPhotoResponse);
	rpc Save (EmployeeRequest) returns(EmployeeResponse);
	rpc SaveAll(stream EmployeeRequest) returns(stream EmployeeResponse);
}

3、编写Server端代码

在编写服务端代码之前，我们需要对proto 文件进行生成代码



如上图：1）我们要先进行勾选Build Action 选择，如图所示，

因为我们这里需要的只是 Server 端，选择生成Server Only

2) 选择这两个之后 我们需要重新生成一下项目

EmployeeService.EmployeeServiceBase 是我们Proto 生成的代码，我们要去重写父类的这些方法

点击查看代码

   public class MyEmployeeService : EmployeeService.EmployeeServiceBase
    {
        private readonly ILogger<MyEmployeeService> _logger;

        public MyEmployeeService(ILogger<MyEmployeeService> logger)
        {
            _logger = logger;
        }

        public override async Task<EmployeeResponse>
            GetByNo(GetByNoRequest request, ServerCallContext context)
        {
            var employee = InMemoryData.Employees.SingleOrDefault(x => x.No == request.No);
            if (employee != null)
            {
                var response = new EmployeeResponse
                {
                    Employee = employee
                };
                return await Task.FromResult(response);
            }
            throw new Exception($"employee is not found :{request.No}");

        }
        public override async Task GetAll(GetAllRequest request, IServerStreamWriter<EmployeeResponse> responseStream, ServerCallContext context)
        {
            foreach (var item in InMemoryData.Employees)
            {
                await responseStream.WriteAsync(new EmployeeResponse
                {
                    Employee = item
                });
            }
            //return base.GetAll(request, responseStream, context);
        }

        public override async Task<AddPhotoResponse> AddPhoto(
            IAsyncStreamReader<AddPhotoRequest> requestStream
            , ServerCallContext context)
        {
            Metadata md = context.RequestHeaders;
            foreach (var item in md)
            {
                Console.WriteLine($"{item.Key}:{item.Value}");
            }

            var data = new List<byte>();
            while (await requestStream.MoveNext())
            {
                Console.WriteLine($"Received: {requestStream.Current.Data.Length}");
                data.AddRange(requestStream.Current.Data);
            }
            Console.WriteLine($"data file with {data.Count} bytes");
            return new AddPhotoResponse
            {
                IsOK = true
            };

        }

        public override async Task SaveAll(
            IAsyncStreamReader<EmployeeRequest> requestStream
            , IServerStreamWriter<EmployeeResponse> responseStream
            , ServerCallContext context)
        {
            while (await requestStream.MoveNext())
            {
                var employee = requestStream.Current.Employee;
                lock (this)
                {
                    InMemoryData.Employees.Add(employee);
                }
                await responseStream.WriteAsync(new EmployeeResponse
                {
                    Employee = employee
                });
            }
            Console.WriteLine("Employees");
            foreach (var item in InMemoryData.Employees)
            {
                Console.WriteLine(item);
            }
            //return base.SaveAll(requestStream, responseStream, context);
        }
    }

4、编写Client客户端代码

1. 我们把服务端的Proto 文件复制一份到Client 端代码 生成一份Client 代码如下图
   
   
2. 需要注意

在编写客户端代码的时候，我遇到了一个错误，提示证书验证失败！，（没有配置证书）

所以我们要加上不对证书进行验证

使用 GrpcChannelOptions() 对证书验证

 using var channel = GrpcChannel.ForAddress("https://localhost:5001", new GrpcChannelOptions()
            {
                HttpClient = null,
                HttpHandler = new HttpClientHandler
                {
                    //方法一
                    ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator
                    //方法二
                    //ServerCertificateCustomValidationCallback = (a, b, c, d) => true
                }
            });

Demo 地址：https://gitee.com/Lovely_Rabbit/basic-principle-exercise