.NET Core Nacos 配置中心

Nacos 是阿里巴巴推出来的一个项目，这是一个更易于构建云原生应用的动态服务发现、配置管理和服务管理平台。
Nacos 致力于帮助您发现、配置和管理微服务。Nacos 提供了一组简单易用的特性集，帮助您快速实现动态服务发现、服务配置、服务元数据及流量管理。
Nacos 帮助您更敏捷和容易地构建、交付和管理微服务平台。 Nacos 是构建以“服务”为中心的现代应用架构 (例如微服务范式、云原生范式) 的服务基础设施。

1、管理 NuGet 包(N)...

nacos-sdk-csharp.Extensions.Configuration

2、appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "Nacos": {
    "Listeners": [
      {
        "Optional": false,
        "DataId": "test",
        "Group": "DEFAULT_GROUP"
      }
    ],
    "Namespace": "public", //命名空间 Namespace 名称
    "ServerAddresses": [ "http://localhost:8848" ],
    "UserName": "nacos",
    "Password": "nacos",
    "AccessKey": "",
    "SecretKey": "",
    "ConfigUseRpc": false,
    "NamingUseRpc": false
  }
}

ConfigUseRpc 和 NamingUseRpc 这2个参数必须存在
若用的是http协议，则都是false，
若用的是grpc协议，则都是true；

3、Nacos 新建配置

4、命名空间(Namespace)，Data Id，Group

5、Program.cs

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
 
namespace NacosProject
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }
 
        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureAppConfiguration((context, builder) =>
                {
                    var config = builder.Build();
                    builder.AddNacosV2Configuration(config.GetSection("Nacos"));
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup();
                });
    }
}

6、Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
 
namespace NacosProject
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
 
        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.Configure(Configuration.GetSection("AppSettings"));
 
            services.AddControllers();
        }
 
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
 
            app.UseRouting();
 
            app.UseAuthorization();
 
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}

7、AppSettings.cs

namespace NacosProject
{
    public class AppSettings
    {
        public string Str { get; set; }
 
        public int num { get; set; }
    }
}

8、ValuesController.cs
之所以 IOptions 没有获取到最新的配置，那是因为它的默认实现不会进行更新操作，也就是从启动到结束，它都是不会变的。
在有配置变更的情景，请尽可能不要用IOptions，用 IOptionsSnapshot 和 IOptionsMonitor 来替代！

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Options;
 
namespace NacosProject.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class ValuesController : ControllerBase
    {
        private readonly IConfiguration _configuration;
        private readonly AppSettings _settings;
        private readonly AppSettings _sSettings;
        private readonly AppSettings _mSettings;
 
        public ValuesController(IConfiguration configuration, IOptions options, IOptionsSnapshot sOptions, IOptionsMonitor _mOptions)
        {
            _configuration = configuration;
            _settings = options.Value;
            _sSettings = sOptions.Value;
            _mSettings = _mOptions.CurrentValue;
        }
 
        [HttpGet]
        public IActionResult Get()
        {
            var connection = _configuration.GetConnectionString("Default");
            var version = _configuration["version"];
            var str1 = Newtonsoft.Json.JsonConvert.SerializeObject(_settings);
            var str2 = Newtonsoft.Json.JsonConvert.SerializeObject(_sSettings);
            var str3 = Newtonsoft.Json.JsonConvert.SerializeObject(_mSettings);
 
            return Ok(new
            {
                connection = connection,
                version = version,
                str1 = str1,
                str2 = str2,
                str3 = str3
            });
        }
    }
}

9、浏览器
地址栏输入：http://localhost:6546/api/values

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