KubeClient是kubernetes 的C#语言客户端简单易用,KubeClient是.NET Core(目标netstandard1.4
)的可扩展Kubernetes API客户端, github地址:https://github.com/tintoy/dotnet-kube-client/
<https://github.com/tintoy/dotnet-kube-client/>,还有一个官方的SDK
https://github.com/kubernetes-client/csharp/
<https://github.com/kubernetes-client/csharp/>  ,这两个sdk的设计哲学上是不一样的,
官方的客户端使用代码生成,代码生成的使用是有限的;
生成的客户端倾向于非惯用,并且对于像Kubernetes那样大的Swagger规范,最终会在客户端类上直接放置太多方法。KubeClient的方法是生成模型类并手动编写实际操作方法,以提供改进的开发使用体验(即有用且一致的异常类型)。

Kubernetes API中的某些操作可以根据传入的参数返回不同的响应。例如,删除a的请求如果调用者指定则v1/Pod返回现有v1/Pod(作为PodV1
模型)DeletePropagationPolicy.Foreground但是如果任何其他类型则返回v1/Status(作为StatusV1模型)的
DeletePropagationPolicy指定。

为了处理这种类型的多态响应,KubeClient使用KubeResultV1模型(及其派生的实现,
KubeResourceResultV1<TResource>和KubeResourceListResultV1<TResource>)。

KubeResourceResultV1<TResource>可以隐式地转换为a TResource或a StatusV1
,因此消费代码可以继续使用客户端,就好像它期望操作只返回资源或期望它只返回StatusV1:

PodV1 existingPod = await client.PodsV1().Delete("mypod", propagationPolicy:
DeletePropagationPolicy.Foreground);

// OR: StatusV1 deleteStatus = await client.PodsV1().Delete("mypod",
propagationPolicy: DeletePropagationPolicy.Background);

KubeClient设计也易于扩展。它的 KubeApiClient提供了Kubernetes API的顶级入口点,扩展方法用于公开更具体的资源客户端。
Ocelot的kubernetes 集成模块就是使用KubeClient ,具体代码参见
https://github.com/ThreeMammals/Ocelot/tree/develop/src/Ocelot.Provider.Kubernetes

<https://github.com/ThreeMammals/Ocelot/tree/develop/src/Ocelot.Provider.Kubernetes>
,这个模块是我们已经在生产环境下使用过了,最近合并进入Ocelot的主干代码,文档参见:
https://ocelot.readthedocs.io/en/latest/features/kubernetes.html
<https://ocelot.readthedocs.io/en/latest/features/kubernetes.html>

简单代码示例参见

using KubeClient;
using KubeClient.Models;
using Ocelot.Logging;
using Ocelot.ServiceDiscovery.Providers;
using Ocelot.Values;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Ocelot.Provider.Kubernetes
{
     public class Kube : IServiceDiscoveryProvider
     {
         private KubeRegistryConfiguration kubeRegistryConfiguration;
         private IOcelotLogger logger;
         private IKubeApiClient kubeApi;

 

        public Kube(KubeRegistryConfiguration kubeRegistryConfiguration,
IOcelotLoggerFactory factory, IKubeApiClientFactory kubeClientFactory)
         {
             this.kubeRegistryConfiguration = kubeRegistryConfiguration;
             this.logger = factory.CreateLogger<Kube>();
             this.kubeApi = kubeClientFactory.Get(kubeRegistryConfiguration);
         }

 

        public async Task<List<Service>> Get()
         {
             var service = await kubeApi.ServicesV1()
                 .Get(kubeRegistryConfiguration.KeyOfServiceInK8s,
kubeRegistryConfiguration.KubeNamespace);
             var services = new List<Service>();
             if (IsValid(service))
             {
                 services.Add(BuildService(service));
             }
             else
             {
                
logger.LogWarning($"namespace:{kubeRegistryConfiguration.KubeNamespace
}service:{kubeRegistryConfiguration.KeyOfServiceInK8s} Unable to use ,it is
invalid. Address must contain host only e.g. localhost and port must be greater
than 0");
             }
             return services;
         }

 

        private bool IsValid(ServiceV1 service)
         {
             if (string.IsNullOrEmpty(service.Spec.ClusterIP) ||
service.Spec.Ports.Count <= 0)
             {
                 return false;
             }

            return true;
         }

 

        private Service BuildService(ServiceV1 serviceEntry)
         {
             var servicePort = serviceEntry.Spec.Ports.FirstOrDefault();
             return new Service(
                 serviceEntry.Metadata.Name,
                 new ServiceHostAndPort(serviceEntry.Spec.ClusterIP,
servicePort.Port),
                 serviceEntry.Metadata.Uid,
                 string.Empty,
                 Enumerable.Empty<string>());
         }
     }
}

常用api

1.deployment


https://github.com/tintoy/dotnet-kube-client/blob/develop/samples/DeploymentWithRollback/Program.cs

<https://github.com/tintoy/dotnet-kube-client/blob/develop/samples/DeploymentWithRollback/Program.cs>

2.service

参看上面ocelot 的代码

3.pod


https://github.com/tintoy/dotnet-kube-client/blob/develop/samples/noob-exec/Program.cs

<https://github.com/tintoy/dotnet-kube-client/blob/develop/samples/noob-exec/Program.cs>

总结

一般操作kubernetes ,二次开发的时候只需要对deployment、service做相关工作。操作起来还是比较简便的。