gRPC由于需要用工具生成代码实现,可开发性不是很高,在扩展这方面不是很友好
最近研究了下,进行了扩展,不需要额外的工具生成,直接使用默认Grpc.Tools生成的代理类即可
相关源码在文章底部
客户端目标:
- 能配置consul地址和服务名称,在调用client时能正确请求到真实的服务地址
- 在调用方法时,能使用Polly策略重试,超时,和熔断
查看gRPC生成的代码,可以看到Client实例化有有两个构造方法,以测试为例
/// Creates a new client for Greeter
/// The channel to use to make remote calls.
public GreeterClient(grpc::ChannelBase channel) : base(channel)
{
} /// Creates a new client for Greeter that uses a custom CallInvoker.
/// The callInvoker to use to make remote calls.
public GreeterClient(grpc::CallInvoker callInvoker) : base(callInvoker)
{
}1.可传入一个ChannelBase实例化
2.可传入一个CallInvoker实例化
Channel可实现为
Channel CreateChannel(string address)
{ var channelOptions = new List()
{ new ChannelOption(ChannelOptions.MaxReceiveMessageLength, int.MaxValue), new ChannelOption(ChannelOptions.MaxSendMessageLength, int.MaxValue),
}; var channel = new Channel(address, ChannelCredentials.Insecure, channelOptions); return channel;
}在这里,可以从consul地址按服务名获取真实的服务地址,生成Channel
CallInvoker为一个抽象类,若要对方法执行过程干预,则需要重写这个方法,大致实现为
public class GRpcCallInvoker : CallInvoker
{ public readonly Channel Channel; public GRpcCallInvoker(Channel channel)
{
Channel = GrpcPreconditions.CheckNotNull(channel);
} public override TResponse BlockingUnaryCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.BlockingUnaryCall(CreateCall(method, host, options), request);
} public override AsyncUnaryCallAsyncUnaryCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.AsyncUnaryCall(CreateCall(method, host, options), request);
} public override AsyncServerStreamingCallAsyncServerStreamingCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.AsyncServerStreamingCall(CreateCall(method, host, options), request);
} public override AsyncClientStreamingCallAsyncClientStreamingCall(Methodmethod, string host, CallOptions options)
{ return Calls.AsyncClientStreamingCall(CreateCall(method, host, options));
} public override AsyncDuplexStreamingCallAsyncDuplexStreamingCall(Methodmethod, string host, CallOptions options)
{ return Calls.AsyncDuplexStreamingCall(CreateCall(method, host, options));
} protected virtual CallInvocationDetailsCreateCall(Methodmethod, string host, CallOptions options) where TRequest : class
where TResponse : class
{ return new CallInvocationDetails(Channel, method, host, options);
}
}这里可以传入上面创建的Channel,在CreateCall方法里,则可以对调用方法进行控制
完整实现为
public class GRpcCallInvoker : CallInvoker
{
GrpcClientOptions _options;
IGrpcConnect _grpcConnect; public GRpcCallInvoker(IGrpcConnect grpcConnect)
{
_options = grpcConnect.GetOptions();
_grpcConnect = grpcConnect;
} public override TResponse BlockingUnaryCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.BlockingUnaryCall(CreateCall(method, host, options), request);
} public override AsyncUnaryCallAsyncUnaryCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.AsyncUnaryCall(CreateCall(method, host, options), request);
} public override AsyncServerStreamingCallAsyncServerStreamingCall(Methodmethod, string host, CallOptions options, TRequest request)
{ return Calls.AsyncServerStreamingCall(CreateCall(method, host, options), request);
} public override AsyncClientStreamingCallAsyncClientStreamingCall(Methodmethod, string host, CallOptions options)
{ return Calls.AsyncClientStreamingCall(CreateCall(method, host, options));
} public override AsyncDuplexStreamingCallAsyncDuplexStreamingCall(Methodmethod, string host, CallOptions options)
{ return Calls.AsyncDuplexStreamingCall(CreateCall(method, host, options));
} protected virtual CallInvocationDetailsCreateCall(Methodmethod, string host, CallOptions options) where TRequest : class
where TResponse : class
{ var methodName = $"{method.ServiceName}.{method.Name}"; var key = methodName.Substring(methodName.IndexOf(".") + 1).ToLower(); var a = _options.MethodPolicies.TryGetValue(key, out PollyAttribute methodPollyAttr); if (!a)
{
_options.MethodPolicies.TryGetValue("", out methodPollyAttr);
}
CallOptions options2; //重写header
if (options.Headers != null)
{
options2 = options;
} else
{
options2 = new CallOptions(_grpcConnect.GetMetadata(), options.Deadline, options.CancellationToken);
} var pollyData = PollyExtension.Invoke(methodPollyAttr, () =>
{ var callRes = new CallInvocationDetails(_grpcConnect.GetChannel(), method, host, options2); return new PollyExtension.PollyData<CallInvocationDetails>() { Data = callRes };
}, $"{methodName}"); var response = pollyData.Data; if (!string.IsNullOrEmpty(pollyData.Error))
{ throw new Exception(pollyData.Error);
} return response; //return new CallInvocationDetails(Channel.Invoke(), method, host, options2); }
}
其中传入了PollyAttribute,由PollyExtension.Invoke来完成Polly策略的实现,具体代码可在源码里找到
从上面代码可以看到,CallInvoker里可以传入了IGrpcConnect,由方法IGrpcConnect.GetChannel()获取Channel
Client实例化
.net FrameWork实现为
public T GetClient()
{ var a = instanceCache.TryGetValue(typeof(T), out object instance); if (!a)
{ var grpcCallInvoker = new GRpcCallInvoker(this);
instance = System.Activator.CreateInstance(typeof(T), grpcCallInvoker);
instanceCache.TryAdd(typeof(T), instance);
} return (T)instance;
}core则简单点,直接注入实现
var client = provider.GetService();
服务端注册
和其它服务注册一样,填入正确的服务地址和名称就行了,但是在Check里得改改,gRPC的健康检查参数是不同的,并且在consul客户端里没有这个参数,得自已写
以下代码是我封装过的,可查看源码
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{ if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapGrpcService();
endpoints.MapGrpcService();
endpoints.MapGet("/", async context =>
{ await context.Response.WriteAsync("Communication with gRPC endpoints must be made through a gRPC client. To learn how to create a client, visit: https://go.microsoft.com/fwlink/?linkid=2086909");
});
}); //注册服务
var consulClient = new CRL.Core.ConsulClient.Consul("http://localhost:8500"); var info = new CRL.Core.ConsulClient.ServiceRegistrationInfo
{
Address = "127.0.0.1",
Name = "grpcServer",
ID = "grpcServer1",
Port = 50001,
Tags = new[] { "v1" },
Check = new CRL.Core.ConsulClient.CheckRegistrationInfo()
{
GRPC = "127.0.0.1:50001",
Interval = "10s",
GRPCUseTLS = false,
DeregisterCriticalServiceAfter = "90m"
}
};
consulClient.DeregisterService(info.ID); var a = consulClient.RegisterService(info);
}客户端完整封装代码为
core扩展方法,设置GrpcClientOptions来配置consul地址和Polly策略,直接注入了Client类型
同时添加了统一header传递,使整个服务都能用一个头发送请求,不用再在方法后面跟参数
public static class GrpcExtensions
{ public static void AddGrpcExtend(this IServiceCollection services, ActionsetupAction, params Assembly[] assemblies)
{
services.Configure(setupAction);
services.AddSingleton();
services.AddScoped(); foreach (var assembyle in assemblies)
{ var types = assembyle.GetTypes(); foreach (var type in types)
{ if(typeof(ClientBase).IsAssignableFrom(type))
{
services.AddSingleton(type);
}
}
}
}
} class Program
{ static IServiceProvider provider; static Program()
{ var builder = new ConfigurationBuilder(); var configuration = builder.Build(); var services = new ServiceCollection();
services.AddSingleton(configuration);
services.AddOptions();
services.AddGrpcExtend(op =>
{
op.Host = "127.0.0.1";
op.Port = 50001;
op.UseConsulDiscover("http://localhost:8500", "grpcServer");//使用consul服务发现
op.AddPolicy("Greeter.SayHello", new CRL.Core.Remoting.PollyAttribute() { RetryCount = 3 });//定义方法polly策略 }, System.Reflection.Assembly.GetExecutingAssembly());
provider = services.BuildServiceProvider();
} static void Main(string[] args)
{
//设置允许不安全的HTTP2支持
AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true); var grpcConnect = provider.GetService(); //认证 //https://www.cnblogs.com/stulzq/p/11897628.html
var token = ""; var headers = new Metadata { { "Authorization", $"Bearer {token}" } };
grpcConnect.SetMetadata(headers);
label1: var client = provider.GetService(); var reply = client.SayHello( new HelloRequest { Name = "test" });
Console.WriteLine("Greeter 服务返回数据: " + reply.Message);
Console.ReadLine(); goto label1;
}
}
运行服务端,结果为
可以看到服务注册成功,状态检查也成功
运行客户端
客户端正确调用并返回了结果
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