來把Day7的service registry例子改成使用Eureka

在ProductService\appsettings.json加入eureka與service registry相關的設定

  "spring": {
    "application": {
      "name": "ProductService"
    }
  },

  "eureka": {
    "client": {
      "serviceUrl": "http://localhost:8761/eureka/",
      "shouldFetchRegistry": false
    },
    "instance": {
      "port": 1111
      // Remove comments to enable SSL requests
      // More changes in Program.cs are required if using direct C2C communications
      //,"securePortEnabled": true
    }
  }

然後修改ProductService\Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Steeltoe.Discovery.Client;

namespace ProductService
{
    public class Startup
    {
        public Startup(IHostingEnvironment env) {
            var builder = new ConfigurationBuilder()
                  .SetBasePath(env.ContentRootPath)
                  .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                  .AddEnvironmentVariables();

            Configuration = builder.Build();
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services) {
            services.AddDiscoveryClient(Configuration);
            services.AddMvc();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env) {
            if (env.IsDevelopment()) {
                app.UseDeveloperExceptionPage();
            }
            app.UseStaticFiles();
            app.UseMvc();
            app.UseDiscoveryClient();
        }
    }
}

打開Eureka server，可以發現ProductService已經註冊了

跟Day7的練習相比，免除了程式自己在啟動與結束時候通知APIGateway的動作，加入幾行code就享有Eureka提供的監控服務，在架構微服務的時候不用分心去處理這塊。

service discovery 待續....

練習改成用Eureka service discovery的時候APIGateway專案一直無法解析ProductService服務名字，交叉用Fortune-Teller-UI測試是ok的，有點擔心也是不相容core 2.0，找到問題後會再補上。