Ocelot网关

Ocelot是一个.net core框架下的网关的开源项目,下图是官方给出的基础实现图,即把后台的多个服务统一到网关处,前端应用:桌面端,web端,app端都只用访问网关即可。

 

Ocelot网关

Ocelot的实现原理就是把客户端对网关的请求(Request),按照configuration.json的映射配置,转发给对应的后端http service,然后从后端http service获取响应(Response)后,再返回给客户端。当然有了网关后,我们可以在网关这层去做统一验证,也可以在网关处统一作监控。

接下来做个Demo

新建三个asp.net core web aip项目:

OcelotGateway网关项目,端口是5000

DemoAAPI项目A,端口是5001

DemoBAPI项目B,端口是5002

(注:端口可以在每个项目的Properties下的launchSettings.json中修改,发布后的端口可以在Program.cs中用UseUrls(“*:5000”)来修改)

对于OcelotGateway:

引用Ocelot的Nuget包:

视图->其他窗口->程序包管理控制台:Install-Package Ocelot

或项目右键“管理Nuget程序包”,在浏览里查找Ocelot进行安装

在OcelotGateway项目中添加一个configuration.json文件,关把它的属性“复制到输出目录”,设成“始终复制”,内容如下:

{

  "ReRoutes": [

    {

      "DownstreamPathTemplate": "/demoaapi/values",

      "DownstreamScheme": "http",

      "DownstreamPort": 5001,

      "DownstreamHost": "localhost",

      "UpstreamPathTemplate": "/demoaapi/values",

      "UpstreamHttpMethod": [ "Get" ],

      "QoSOptions": {

        "ExceptionsAllowedBeforeBreaking": 3,

        "DurationOfBreak": 10,

        "TimeoutValue": 5000

      },

      "HttpHandlerOptions": {

        "AllowAutoRedirect": false,

        "UseCookieContainer": false

      },

      "AuthenticationOptions": {

        "AuthenticationProviderKey": "",

        "AllowedScopes": []

      }

    },

    {

      "DownstreamPathTemplate": "/demobapi/values",

      "DownstreamScheme": "http",

      "DownstreamPort": 5002,

      "DownstreamHost": "localhost",

      "UpstreamPathTemplate": "/demobapi/values",

      "UpstreamHttpMethod": [ "Get" ],

      "QoSOptions": {

        "ExceptionsAllowedBeforeBreaking": 3,

        "DurationOfBreak": 10,

        "TimeoutValue": 5000

      },

      "HttpHandlerOptions": {

        "AllowAutoRedirect": false,

        "UseCookieContainer": false

      },

      "AuthenticationOptions": {

        "AuthenticationProviderKey": "",

        "AllowedScopes": []

      }

    }

  ]

}

接下来对OcelotGateway的Program.cs进行改造

 

using Microsoft.AspNetCore.Hosting;

using Microsoft.Extensions.Configuration;

using Microsoft.Extensions.DependencyInjection;

 

namespace OcelotGateway

{

    public class Program

    {

        public static void Main(string[] args)

        {

            BuildWebHost(args).Run();

        }

        public static IWebHost BuildWebHost(string[] args)

        {

            IWebHostBuilder builder = new WebHostBuilder();

            //注入WebHostBuilder

            return builder.ConfigureServices(service =>

                {

                    service.AddSingleton(builder);

                })

                //加载configuration配置文人年

                .ConfigureAppConfiguration(conbuilder =>

                {

                    conbuilder.AddJsonFile("configuration.json");

                })

                .UseKestrel()

                .UseUrls("http://*:5000")

                .UseStartup<Startup>()

                .Build();

        }

    }

}

同时,修改Startup.cs

using Microsoft.AspNetCore.Builder;

using Microsoft.AspNetCore.Hosting;

using Microsoft.Extensions.Configuration;

using Microsoft.Extensions.DependencyInjection;

using Ocelot.DependencyInjection;

using Ocelot.Middleware;

 

namespace OcelotGateway

{

    public class Startup

    {

        public Startup(IConfiguration configuration)

        {

            Configuration = configuration;

        }

        public IConfiguration Configuration { get; }     

        public void ConfigureServices(IServiceCollection services)

        {      

            //注入配置文件,AddOcelot要求参数是IConfigurationRoot类型,所以要作个转换

            services.AddOcelot(Configuration as ConfigurationRoot);

        }

        public  void Configure(IApplicationBuilder app, IHostingEnvironment env)

        {

            //添加中间件

            app.UseOcelot().Wait();

        }

    }

}

为了测试数据好看,我们把DemoAAPI项目和DemoBAPI项目的ValuesController作一下修改:

    [Route("demoaapi/[controller]")]

    public class ValuesController : Controller

    {       

        [HttpGet]

        public IEnumerable<string> Get()

        {

            return new string[] { "DemoA服务", "请求" };

        }

……

}

 

    [Route("demobapi/[controller]")]

    public class ValuesController : Controller

    {       

        [HttpGet]

        public IEnumerable<string> Get()

        {

            return new string[] { "DemoB服务", "请求" };

        }

……

}

 

最后在解决方案属性->多个启动项目中,把DemoAAPI,DemoBAPI,OcelotGateway都设成启动,开始启动解决方案,效果如下图

内容版权声明:除非注明,否则皆为本站原创文章。

转载注明出处:https://www.heiqu.com/wpjgjf.html