前置条件: 《Dapr 运用》
改造 ProductService 以提供 gRPC 服务
- 从 NuGet 或程序包管理控制台安装 gRPC 服务必须的包
- Grpc.AspNetCore
- 配置 Http/2
- gRPC 服务需要 Http/2 协议
public static IHostBuilder CreateHostBuilder(string[] args)
{
return Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.ConfigureKestrel(options =>
{
options.Listen(IPAddress.Loopback, 50![](https://img2018.cnblogs.com/blog/757544/201912/757544-20191218205830077-211023565.png)
01, listenOptions =>
{
listenOptions.Protocols = HttpProtocols.Http2;
});
});
webBuilder.UseStartup();
});
}
```
- 新建了 product.proto 以定义 GRPC 服务,它需要完成的内容是返回所有产品集合,当然目前产品内容只有一个 ID
- 定义产品 proto
syntax = "proto3";
package productlist.v1;
option csharp_namespace = "ProductList.V1";
service ProductRPCService{
rpc GetAllProducts(ProductListRequest) returns(ProductList);
}
message ProductListRequest{
}
message ProductList {
repeated Product results = 1;
}
message Product {
string ID=1;
}
- 说明
- 定义产品列表 gRPC 服务,得益于宇宙第一 IDE Visual Studio ,只要添加 Grpc.Tools 包就可以自动生成 gRPC 所需的代码,这里不再需要手动去添加 Grpc.Tools ,官方提供的 Grpc.AspNetCore 中已经集成了
- 定义了一个服务 ProductRPCService
- 定义了一个函数 ProductRPCService
- 定义了一个请求构造 ProductListRequest ,内容为空
- 定义了一个请求返回构造 ProductList ,使用 repeated 表明返回数据是集合
- 定义了一个数据集合中的一个对象 Product
- 添加 ProductListService 文件,内容如下
public class ProductListService : ProductRPCService.ProductRPCServiceBase
{
private readonly ProductContext _productContext;
public ProductListService(ProductContext productContext)
{
_productContext = productContext;
}
public override async Task<ProductList.V1.ProductList> GetAllProducts(ProductListRequest request, ServerCallContext context)
{
IList<Product> results = await _productContext.Products.ToListAsync();
var productList = new ProductList.V1.ProductList();
foreach (Product item in results)
{
productList.Results.Add(new ProductList.V1.Product
{
ID = item.ProductID.ToString()
});
}
return productList;
}
}
- 在 Startup.cs 修改代码如下
public void ConfigureServices(IServiceCollection services)
{
//启用 gRPC 服务
services.AddGrpc();
services.AddTransient<ProductListService>();
...
}
- 这里的 services.AddTransient(); 的原因是在 Dapr 中需要使用构造器注入,以完成
GetAllProducts(...)
函数的调用
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints =>
{
...
//添加 gRPC 到路由管道中
endpoints.MapGrpcService<DaprClientService>();
});
}
- 这里添加的代码的含义分别是启用 gRPC 服务和添加 gRPC 路由。得益于
ASP.NET Core
中间件的优秀设计,ASP.NET Core
可同时支持 Http 服务。 - 添加 daprclient.proto 文件以生成 Dapr Grpc 服务,daprclient.proto 内容如下
syntax = "proto3";
package daprclient;
import "google/protobuf/any.proto";
import "google/protobuf/empty.proto";
import "google/protobuf/duration.proto";
option java_outer_classname = "DaprClientProtos";
option java_package = "io.dapr";
// User Code definitions
service DaprClient {
rpc OnInvoke (InvokeEnvelope) returns (google.protobuf.Any) {}
rpc GetTopicSubscriptions(google.protobuf.Empty) returns (GetTopicSubscriptionsEnvelope) {}
rpc GetBindingsSubscriptions(google.protobuf.Empty) returns (GetBindingsSubscriptionsEnvelope) {}
rpc OnBindingEvent(BindingEventEnvelope) returns (BindingResponseEnvelope) {}
rpc OnTopicEvent(CloudEventEnvelope) returns (google.protobuf.Empty) {}
}
message CloudEventEnvelope {
string id = 1;
string source = 2;
string type = 3;
string specVersion = 4;
string dataContentType = 5;
string topic = 6;
google.protobuf.Any data = 7;
}
message BindingEventEnvelope {
string name = 1;
google.protobuf.Any data = 2;
map<string,string> metadata = 3;
}
message BindingResponseEnvelope {
google.protobuf.Any data = 1;
repeated string to = 2;
repeated State state = 3;
string concurrency = 4;
}
message InvokeEnvelope {
string method = 1;
google.protobuf.Any data = 2;
map<string,string> metadata = 3;
}
message GetTopicSubscriptionsEnvelope {
repeated string topics = 1;
}
message GetBindingsSubscriptionsEnvelope {
repeated string bindings = 1;
}
message State {
string key = 1;
google.protobuf.Any value = 2;
string etag = 3;
map<string,string> metadata = 4;
StateOptions options = 5;
}
message StateOptions {
string concurrency = 1;
string consistency = 2;
RetryPolicy retryPolicy = 3;
}
message RetryPolicy {
int32 threshold = 1;
string pattern = 2;
google.protobuf.Duration interval = 3;
}
- 说明
- 此文件为官方提供,Dapr 0.3 版本之前提供的已经生成好的代码,现在看源码可以看出已经改为提供 proto 文件了,这里我认为提供 proto 文件比较合理
- 此文件定义了5个函数,此文主要讲的就是
OnInvoke()
函数 OnInvoke()
请求构造为 InvokeEnvelope
- method 提供调用方法名称
- data 请求数据
- metadata 额外数据,此处使用键值对形式体现
- 创建 DaprClientService.cs 文件,此文件用于终结点路由,内容为
public class DaprClientService : DaprClient.DaprClientBase
{
private readonly ProductListService _productListService;
/// <summary>
/// Initializes a new instance of the <see cref="ProductService" /> class.
/// </summary>
/// <param name="productListService"></param>
public DaprClientService(ProductListService productListService)
{
_productListService = productListService;
}
public override async Task<Any> OnInvoke(InvokeEnvelope request, ServerCallContext context)
{
switch (request.Method)
{
case "GetAllProducts":
ProductListRequest productListRequest = ProductListRequest.Parser.ParseFrom(request.Data.Value);
ProductList.V1.ProductList productsList = await _productListService.GetAllProducts(productListRequest, context);
return Any.Pack(productsList);
}
return null;
}
}
- 说明
- 使用构造器注入已定义好的
ProductListService
-
InvokeEnvelope
中的 Method
用于路由数据 - 使用
ProductListRequest.Parser.ParseFrom
转换请求构造 - 使用
Any.Pack()
打包需要返回的数据
- 运行 productService
dapr run --app-id productService --app-port 5001 --protocol grpc dotnet run
小结
至此,ProductService 服务完成。此时 ProductService.Api.csproj Protobuf 内容为
<ItemGroup>
<Protobuf Include="Protos\daprclient.proto" GrpcServices="Server" />
<Protobuf Include="Protos\productList.proto" GrpcServices="Server" />
</ItemGroup>
改造 StorageService 服务以完成 Dapr GRPC 服务调用
- 添加 productList.proto 文件,内容同 ProductService 中的 productList.proto
- 添加 dapr.proto 文件,此文件也为官方提供,内容为
syntax = "proto3";
package dapr;
import "google/protobuf/any.proto";
import "google/protobuf/empty.proto";
import "google/protobuf/duration.proto";
option java_outer_classname = "DaprProtos";
option java_package = "io.dapr";
option csharp_namespace = "Dapr.Client.Grpc";
// Dapr definitions
service Dapr {
rpc PublishEvent(PublishEventEnvelope) returns (google.protobuf.Empty) {}
rpc InvokeService(InvokeServiceEnvelope) returns (InvokeServiceResponseEnvelope) {}
rpc InvokeBinding(InvokeBindingEnvelope) returns (google.protobuf.Empty) {}
rpc GetState(GetStateEnvelope) returns (GetStateResponseEnvelope) {}
rpc SaveState(SaveStateEnvelope) returns (google.protobuf.Empty) {}
rpc DeleteState(DeleteStateEnvelope) returns (google.protobuf.Empty) {}
}
message InvokeServiceResponseEnvelope {
google.protobuf.Any data = 1;
map<string,string> metadata = 2;
}
message DeleteStateEnvelope {
string key = 1;
string etag = 2;
StateOptions options = 3;
}
message SaveStateEnvelope {
repeated StateRequest requests = 1;
}
message GetStateEnvelope {
string key = 1;
string consistency = 2;
}
message GetStateResponseEnvelope {
google.protobuf.Any data = 1;
string etag = 2;
}
message InvokeBindingEnvelope {
string name = 1;
google.protobuf.Any data = 2;
map<string,string> metadata = 3;
}
message InvokeServiceEnvelope {
string id = 1;
string method = 2;
google.protobuf.Any data = 3;
map<string,string> metadata = 4;
}
message PublishEventEnvelope {
string topic = 1;
google.protobuf.Any data = 2;
}
message State {
string key = 1;
google.protobuf.Any value = 2;
string etag = 3;
map<string,string> metadata = 4;
StateOptions options = 5;
}
message StateOptions {
string concurrency = 1;
string consistency = 2;
RetryPolicy retryPolicy = 3;
}
message RetryPolicy {
int32 threshold = 1;
string pattern = 2;
google.protobuf.Duration interval = 3;
}
message StateRequest {
string key = 1;
google.protobuf.Any value = 2;
string etag = 3;
map<string,string> metadata = 4;
StateRequestOptions options = 5;
}
message StateRequestOptions {
string concurrency = 1;
string consistency = 2;
StateRetryPolicy retryPolicy = 3;
}
message StateRetryPolicy {
int32 threshold = 1;
string pattern = 2;
google.protobuf.Duration interval = 3;
}
- 说明
- 此文件提供6个 GRPC 服务,此文介绍的函数为
InvokeService()
- 请求构造为 InvokeServiceEnvelope
- id 请求的服务的 --app-id ,比如 productService
- method 请求的方法
- data 请求函数的签名
- metadata 元数据键值对
- 修改 StorageController 中的
InitialStorage()
函数为
/// <summary>
/// 初始化仓库.
/// </summary>
/// <returns>是否成功.</returns>
[HttpGet("InitialStorage")]
public async Task<bool> InitialStorage()
{
string defaultPort = Environment.GetEnvironmentVariable("DAPR_GRPC_PORT") ?? "5001";
// Set correct switch to make insecure gRPC service calls. This switch must be set before creating the GrpcChannel.
AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
// Create Client
string daprUri = $"http://127.0.0.1:{defaultPort}";
GrpcChannel channel = GrpcChannel.ForAddress(daprUri);
var client = new Dapr.Client.Grpc.Dapr.DaprClient(channel);
InvokeServiceResponseEnvelope result = await client.InvokeServiceAsync(new InvokeServiceEnvelope
{
Method = "GetAllProducts",
Id = "productService",
Data = Any.Pack(new ProductListRequest())
});
ProductList.V1.ProductList productResult = ProductList.V1.ProductList.Parser.ParseFrom(result.Data.Value);
var random = new Random();
foreach (Product item in productResult.Results)
{
_storageContext.Storage.Add(new Storage
{
ProductID = Guid.Parse(item.ID),
Amount = random.Next(1, 1000)
});
}
await _storageContext.SaveChangesAsync();
return true;
}
- 启动 StorageService
dapr run --app-id storageService --app-port 5003 dotnet run
- 使用 Postman 请求 StorageService 的 InitialStorage
- 使用 MySql Workbench 查看结果
小结
至此,以 Dapr 框架使用 GRPC 客户端在 StorageService 中完成了对 ProductService 服务的调用。
源码地址