.netcore的微服务学习（二）--网关（gateway）之Ocelot学习

一，引用ocelot，本文测试16版本有BUG，只好使用15.0.7

二，startup的配置，很简单，就是注册和添加管道

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Ocelot.DependencyInjection;
using Ocelot.Middleware;

namespace OcelotDemo
{
    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.AddOcelot();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            ///使用coelot
            app.UseOcelot();
        }
    }
}

三，写配置文件,5001是我们控制台启动的端口，这个注意不要映射错

{
  "ReRoutes": [
    {
      "DownstreamPathTemplate": "/api/{url}", //服务地址--url变量
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 5001 //服务端口
        } //可以多个，自行负载均衡
      ],
      "UpstreamPathTemplate": "/OcelotDemo/{url}", //网关地址--url变量   //冲突的还可以加权重Priority
      "UpstreamHttpMethod": [ "Get", "Post" ]
    }
  ]
}

四，启动项目

dotnet OcelotDemo.dll urls="http://*:5003" --ip="127.0.0.1" --port=5003

五，访问http://localhost:5003/OcelotDemo/User/Get，这个可以拿到http://localhost:5001/api/User/Get地址的值，由于网关地址映射

六，多实例的配置

//*****************************多地址多实例,提供多种路由，可是不是集群********************************
{
  "ReRoutes": [
    {
      "DownstreamPathTemplate": "/api/{url}", //服务地址--url变量
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 5001 //服务端口
        } //可以多个，自行负载均衡
      ],
      "UpstreamPathTemplate": "/OcelotDemo5001/{url}", //网关地址--url变量   //冲突的还可以加权重Priority
      "UpstreamHttpMethod": [ "Get", "Post" ]
    },
    {
      "DownstreamPathTemplate": "/api/{url}", //服务地址--url变量
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 5002 //服务端口
        }
      ],
      "UpstreamPathTemplate": "/OcelotDemo5002/{url}", //网关地址--url变量
      "UpstreamHttpMethod": [ "Get", "Post" ]
    }
  ]
}

访问的方法是http://localhost:52830/OcelotDemo5001/User/get和http://localhost:52830/OcelotDemo5002/User/get，所以需要访问两个地址，这个不是集群

七，单服务的负载均衡配置，如下

//*****************************单地址多实例负载均衡********************************
{
  "ReRoutes": [
    {
      "DownstreamPathTemplate": "/api/{url}", //服务地址--url变量
      "DownstreamScheme": "http",
      "DownstreamHostAndPorts": [
        {
          "Host": "localhost",
          "Port": 5001 //服务端口
        } //可以多个，自行负载均衡
        ,
        {
          "Host": "localhost",
          "Port": 5002 //服务端口
        }
      ],
      "UpstreamPathTemplate": "/OcelotDemo/{url}", //网关地址--url变量   //冲突的还可以加权重Priority
      "UpstreamHttpMethod": [ "Get", "Post" ],
      "LoadBalancerOptions": {
        "Type": "RoundRobin" //轮询      LeastConnection-最少连接数的服务器   NoLoadBalance不负载均衡 三种模式
      }
    }
  ]
}

启动网关dotnet OcelotDemo.dll urls="http://*:5003" --ip="127.0.0.1" --port=5003，我们可以使用同一个地址访问，http://localhost:5003/OcelotDemo/User/Get

 八，UserController的写法请求的get接口

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;

namespace ConsulTestDemo.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    public class UserController : ControllerBase
    {
        public IConfiguration _configuration;
        public UserController(IConfiguration configuration)
        {
            _configuration = configuration;
        }

        [HttpGet]
        public string Get()
        {
            return int.Parse(_configuration["port"]).ToString() + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"); //命令行参数必须传入   
        }
    }
}