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微服务中有关键的几项技术，其中网关和服务服务发现，服务注册相辅相成。
首先解释几个本次教程中需要的术语
网关 Gateway（API GW / API 网关），顾名思义，是企业 IT 在系统边界上提供给外部访问内部接口服务的统一入口，简化了外部由于多服务协同完成任务时的繁琐配置。网关组件有Kong，ocelot,
服务发现：通过网关访问内部各个微服务，网关要找到所需服务的过程称为服务发现
服务注册：既然有服务发现，前提是要把所需服务提前“录入”，这个录入的过程称为服务注册。服务注册可配置文件（人肉方式不推荐），也可用服务注册组件如Consul或者Eureka等等（推荐）
搭建Consul集群(Windows)
官网下载Consul程序，https://www.consul.io/downloads.html
下载下来就是一个可执行文件Consul.exe
Consul有两种代理模式，一种server,一种client,官方建议Server端达到3台以上才可高可用，但不要太多，太多会给集群间数据同步造成压力，client数量不限。
多个server端之间会选择出一个leader,当一个server的leader宕机则会从其他server端”投票“选择新的leader
实践
这里server我们用2台实验
192.168.74.55
192.168.74.54
1台Client
192.168.74.161
consul启动有两种方式一种是命令行，一种是配置文件的方式。
命令行方式启动一个consul的server端
consul agent -server -ui -bootstrap-expect 2 -data-dir opt/consul/data -node ServerMaster -bind 192.168.74.55 -client 192.168.74.55
关键参数说明
-server：server模式启动
-ui ：开启ui界面（consul.exe内部带了GUI图形界面操作）
-bootstrap-expect 2：server端到2个时集群生效
-data-dir：consul产生的文件路径（consul自己会产生一下数据存储的位置）
-node：此节点名称
-bind：集群内部通信地址，默认0.0.0.0
-client：此节点绑定的通讯地址
以上只是关键参数，以下是完整参数说明：
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但是命令启动很繁琐，所以推荐下面的配置文件的方式启动
在consul同文件夹下建立一个server.json的配置文件
{
"datacenter": "dc1",
"data_dir": "opt/consul/data",
"node_name": "consul-server01",
"server": true,
"bootstrap_expect": 2,
"bind_addr": "192.168.74.55",
"client_addr": "192.168.74.55",
"ui":true
}
为了快速启动，再建立一个bat批处理文件runconsul.bat
consul agent -config-dir server.json
pause
双击runconsul.bat启动consul
在192.168.74.54服务器开启一个server端继续以上操作。
命令方式启动
consul agent -server -ui -data-dir opt/consul/data -node Server01 -bind 192.168.74.54 -client 192.168.74.54 -join=192.168.74.55
-join将192.168.74.54加入到192.168.74.55服务器
配置文件方式：
{
"datacenter": "dc1",
"data_dir": "opt/consul/data",
"node_name": "consul-server2",
"server": true,
"bind_addr": "192.168.74.54",
"client_addr": "192.168.74.54",
"ui":true,
"retry_join": ["192.168.74.55"],
"retry_interval": "30s",
"rejoin_after_leave": true,
"start_join":["192.168.74.55"]
}
在192.168.74.161服务器开启一个consul的client端
命令方式：
consul agent -ui -data-dir opt/consul/data -node ServerSlave -bind 192.168.74.161 -client 192.168.74.161 -join 192.168.74.55
配置文件方式：
{
"datacenter": "dc1",
"data_dir": "opt/consul/data",
"node_name": "consul-client01",
"server": false,
"bind_addr": "192.168.74.161",
"client_addr": "192.168.74.161",
"ui":true,
"retry_join": ["192.168.74.55"],
"retry_interval": "30s",
"rejoin_after_leave": true,
"start_join":["192.168.74.55"]
}
效果
简单Consul集群到这里就搭建成功，只要访问三台服务器任意一个都可数据同步，演示：
image
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netcore集成Consul服务注册
首先新建一个ConsulClient的类库
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ConsulRegister.csproj所需组件如下：
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>netstandard2.0</TargetFramework>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Consul" Version="0.7.2.6" />
<PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="2.1.0" />
<PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.1.0" />
<PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="2.1.0" />
<PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="2.1.0" />
<PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="2.1.0" />
</ItemGroup>
</Project>
// 服务发现自动注册，无需手动绑定本机地址，会自动扫描本地ipv4地址和localhost地址，项目中无需再手动创建健康检查接口
// ServiceDiscoveryOptions.cs
using System;
using System.Collections.Generic; using System.Text;
namespace ConsulRegister
{ /// <summary>
/// 服务治理第三方组件Consul相关配置参数 /// </summary>
public class ServiceDiscoveryOptions
{ public string ServiceName { get; set; } public ConsulOptions Consul { get; set; }
} public class ConsulOptions
{ public string HttpEndPoint { get; set; }
}
}
RegisterToConsulExtension.cs
using Consul;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Hosting.Server.Features;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using System;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
namespace ConsulRegister
{
public static class RegisterToConsulExtension
{
/// <summary>
/// Add Consul
/// 添加consul
/// </summary>
/// <param name="services"></param>
/// <param name="configuration"></param>
/// <returns></returns>
public static IServiceCollection AddConsul(this IServiceCollection services, IConfiguration configuration)
{
// configuration Consul register address
//配置consul注册地址
services.Configure<ServiceDiscoveryOptions>(configuration.GetSection("ServiceDiscovery"));
//configuration Consul client
//配置consul客户端
services.AddSingleton<IConsulClient>(sp => new Consul.ConsulClient(config =>
{
var consulOptions = sp.GetRequiredService<IOptions<ServiceDiscoveryOptions>>().Value;
if (!string.IsNullOrWhiteSpace(consulOptions.Consul.HttpEndPoint))
{
config.Address = new Uri(consulOptions.Consul.HttpEndPoint);
}
}));
return services;
}
/// <summary>
/// use Consul
/// 使用consul
/// The default health check interface format is http://host:port/HealthCheck
/// 默认的健康检查接口格式是 http://host:port/HealthCheck
/// </summary>
/// <param name="app"></param>
/// <returns></returns>
public static IApplicationBuilder UseConsul(this IApplicationBuilder app)
{
IConsulClient consul = app.ApplicationServices.GetRequiredService<IConsulClient>();
IApplicationLifetime appLife = app.ApplicationServices.GetRequiredService<IApplicationLifetime>();
IOptions<ServiceDiscoveryOptions> serviceOptions = app.ApplicationServices.GetRequiredService<IOptions<ServiceDiscoveryOptions>>();
var features = app.Properties["server.Features"] as FeatureCollection;
var port = new Uri(features.Get<IServerAddressesFeature>()
.Addresses
.FirstOrDefault()).Port;
Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine($"application port is :{port}");
var addressIpv4Hosts = NetworkInterface.GetAllNetworkInterfaces()
.OrderByDescending(c => c.Speed)
.Where(c => c.NetworkInterfaceType != NetworkInterfaceType.Loopback && c.OperationalStatus == OperationalStatus.Up);
foreach (var item in addressIpv4Hosts)
{
var props = item.GetIPProperties();
//this is ip for ipv4
//这是ipv4的ip地址
var firstIpV4Address = props.UnicastAddresses
.Where(c => c.Address.AddressFamily == AddressFamily.InterNetwork)
.Select(c => c.Address)
.FirstOrDefault().ToString();
var serviceId = $"{serviceOptions.Value.ServiceName}_{firstIpV4Address}:{port}";
var httpCheck = new AgentServiceCheck()
{
DeregisterCriticalServiceAfter = TimeSpan.FromMinutes(1),
Interval = TimeSpan.FromSeconds(30),
//this is default health check interface
//这个是默认健康检查接口
HTTP = $"{Uri.UriSchemeHttp}://{firstIpV4Address}:{port}/HealthCheck",
};
var registration = new AgentServiceRegistration()
{
Checks = new[] { httpCheck },
Address = firstIpV4Address.ToString(),
ID = serviceId,
Name = serviceOptions.Value.ServiceName,
Port = port
};
consul.Agent.ServiceRegister(registration).GetAwaiter().GetResult();
//send consul request after service stop
//当服务停止后想consul发送的请求
appLife.ApplicationStopping.Register(() =>
{
consul.Agent.ServiceDeregister(serviceId).GetAwaiter().GetResult();
});
Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine($"health check service:{httpCheck.HTTP}");
}
//register localhost address
//注册本地地址
var localhostregistration = new AgentServiceRegistration()
{
Checks = new[] { new AgentServiceCheck()
{
DeregisterCriticalServiceAfter = TimeSpan.FromMinutes(1),
Interval = TimeSpan.FromSeconds(30),
HTTP = $"{Uri.UriSchemeHttp}://localhost:{port}/HealthCheck",
} },
Address = "localhost",
ID = $"{serviceOptions.Value.ServiceName}_localhost:{port}",
Name = serviceOptions.Value.ServiceName,
Port = port
};
consul.Agent.ServiceRegister(localhostregistration).GetAwaiter().GetResult();
//send consul request after service stop
//当服务停止后想consul发送的请求
appLife.ApplicationStopping.Register(() =>
{
consul.Agent.ServiceDeregister(localhostregistration.ID).GetAwaiter().GetResult();
});
app.Map("/HealthCheck", s =>
{
s.Run(async context =>
{
await context.Response.WriteAsync("ok");
});
});
return app;
}
}
}
再新建一个.netcore的webapi项目WebA，并且引用ConsulRegister项目
在WebA项目中的Startup.cs文件中加入Consul服务
public void ConfigureServices(IServiceCollection services)
{
services.AddConsul(Configuration);
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}
// 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.UseConsul();
app.UseMvc();
}
在WebA项目的appsettings.json配置文件中加入以下Consul服务端配置
{
"Logging": {
"LogLevel": {
"Default": "Warning"
}
},
"AllowedHosts": "*",
"ServiceDiscovery": {
"ServiceName": "A",
"Consul": {
"HttpEndpoint": "http://192.168.74.161:8500"
}
}
}
这里服务注册就算完成
Ocelot网关搭建
接下来继续Ocelot借助于Consul实现服务发现
新建项目Ocelot.Gateway
将以下依赖加入Ocelot.Gateway.csproj中：
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp2.1</TargetFramework>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.AspNetCore.App" />
<PackageReference Include="Ocelot" Version="12.0.1" />
<PackageReference Include="Ocelot.Provider.Consul" Version="0.1.2" />
</ItemGroup>
<ItemGroup>
<Content Update="ocelot.json">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</Content>
</ItemGroup>
</Project>
新建ocelot.json文件
{
"ReRoutes": [
{
"UseServiceDiscovery": true,
"DownstreamPathTemplate": "/{url}",
"DownstreamScheme": "http",
"ServiceName": "A",
"LoadBalancerOptions": {
"Type": "RoundRobin"
},
"UpstreamPathTemplate": "/a/{url}",
"UpstreamHttpMethod": [ "Get", "Post" ],
"ReRoutesCaseSensitive": false
}
],
"GlobalConfiguration": {
// 使用Consul服务治理
"ServiceDiscoveryProvider": {
"Host": "192.168.74.161",
"Port": 8500,
"ConfigurationKey": "Oceolot_A" //存储在Consul上的Key
}
}
}
修改Startup.cs文件如下：
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.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
services.AddOcelot( new ConfigurationBuilder()
.AddJsonFile("ocelot.json", optional: false, reloadOnChange: true).Build())
.AddConsul()
.AddConfigStoredInConsul();
} // 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();
} else {
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseOcelot().Wait();
}
}
发布WebA后复制两份分别启动
dotnet WebA.dll --urls="http://0.0.0.0:2001"
dotnet WebA.dll --urls="http://0.0.0.0:2002"
到这里相当于2001和2002程序简单集群了一下
可以发现日志中有 http://192.168.74.161:2002/HealthCheck调用信息：
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这其实是consul进行健康检查进行的调用。
启动多个程序后，打开浏览器打开Consuld界面会发现注册了两个服务
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这里ocelot网关和consul的服务注册和发现就算初步集成。
生产部署
如果生产环境是windows的情况，将consul做成windows服务即可
sc create "ConsulServer" binPath="F:\XXX\consul.exe agent -config-dir XXX.json"
生产环境是linux则借助systemd做成守护进程即可
生产环境是docker，运行以下命令部署单节点，集群类似
docker run --restart=always -d --name=c13 -p 8500:8500 consul agent -server -bootstrap -ui -data-dir tmp/consul -bind 0.0.0.0 -client 0.0.0.0 -node dockerserver
目前集群搭建成功，但是连接的话如果指定某个端点的ip进行连接，端点宕机，就会导致网关一样无法连接consul进行服务发现。所以还需进行配置暴露一个端点让客户端连接，配置详情：https://www.consul.io/docs/connect/configuration.html
不过也可以做成虚拟ip进行多台consul的负载。客户端连接虚拟ip即可
项目地址：
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