From 88034a5f9f1a95bdea969e3972a852976a87e656 Mon Sep 17 00:00:00 2001
From: WebMed <a.aisati@gmail.com>
Date: Mon, 10 Feb 2020 23:52:55 +0100
Subject: [PATCH] Updated KubeProvider to use pod endpoints instead of service

---
 .../EndPointClientV1.cs                       | 41 +++++++++++++++++++
 .../KubeClientExtensions.cs                   | 12 ++++++
 .../KubeProvider.cs                           | 36 +++++++---------
 .../Ocelot.Provider.Kubernetes.csproj         |  4 +-
 4 files changed, 69 insertions(+), 24 deletions(-)
 create mode 100644 src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/EndPointClientV1.cs
 create mode 100644 src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/KubeClientExtensions.cs

diff --git a/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/EndPointClientV1.cs b/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/EndPointClientV1.cs
new file mode 100644
index 00000000..dfae202b
--- /dev/null
+++ b/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/EndPointClientV1.cs
@@ -0,0 +1,41 @@
+using HTTPlease;
+using KubeClient;
+using KubeClient.Models;
+using KubeClient.ResourceClients;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Ocelot.Provider.Kubernetes.KubeApiClientExtensions
+{
+    public class EndPointClientV1 : KubeResourceClient
+    {
+        public EndPointClientV1(IKubeApiClient client) : base(client)
+        {
+        }
+
+        public async Task<EndpointsV1> Get(string serviceName, string kubeNamespace = null, CancellationToken cancellationToken = default)
+        {
+            if (string.IsNullOrEmpty(serviceName)) throw new ArgumentNullException(nameof(serviceName));
+
+            var response = await Http.GetAsync(
+                Requests.Collection.WithTemplateParameters(new
+                {
+                    Namespace = kubeNamespace ?? KubeClient.DefaultNamespace,
+                    ServiceName = serviceName
+                }),
+                cancellationToken: cancellationToken
+            );
+
+            if (response.IsSuccessStatusCode)
+                return await response.ReadContentAsAsync<EndpointsV1>();
+
+            return null;
+        }
+
+        public static class Requests
+        {
+            public static readonly HttpRequest Collection = KubeRequest.Create("api/v1/namespaces/{Namespace}/endpoints/{ServiceName}");
+        }
+    }
+}
diff --git a/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/KubeClientExtensions.cs b/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/KubeClientExtensions.cs
new file mode 100644
index 00000000..1985dda8
--- /dev/null
+++ b/src/Ocelot.Provider.Kubernetes/KubeApiClientExtensions/KubeClientExtensions.cs
@@ -0,0 +1,12 @@
+using KubeClient;
+
+namespace Ocelot.Provider.Kubernetes.KubeApiClientExtensions
+{
+    public static class KubeClientExtensions
+    {
+        public static EndPointClientV1 EndPointsV1(this IKubeApiClient kubeClient)
+        {
+            return kubeClient.ResourceClient(client => new EndPointClientV1(client));
+        }
+    }
+}
diff --git a/src/Ocelot.Provider.Kubernetes/KubeProvider.cs b/src/Ocelot.Provider.Kubernetes/KubeProvider.cs
index 22f5b115..a4615b8c 100644
--- a/src/Ocelot.Provider.Kubernetes/KubeProvider.cs
+++ b/src/Ocelot.Provider.Kubernetes/KubeProvider.cs
@@ -6,14 +6,15 @@ using Ocelot.Values;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Ocelot.Provider.Kubernetes.KubeApiClientExtensions;
 
 namespace Ocelot.Provider.Kubernetes
 {
     public class Kube : IServiceDiscoveryProvider
     {
         private KubeRegistryConfiguration kubeRegistryConfiguration;
-        private IOcelotLogger logger;
-        private IKubeApiClient kubeApi;
+        private readonly IOcelotLogger logger;
+        private readonly IKubeApiClient kubeApi;
 
         public Kube(KubeRegistryConfiguration kubeRegistryConfiguration, IOcelotLoggerFactory factory, IKubeApiClient kubeApi)
         {
@@ -22,14 +23,13 @@ namespace Ocelot.Provider.Kubernetes
             this.kubeApi = kubeApi;
         }
 
-
         public async Task<List<Service>> Get()
         {
-            var service = await kubeApi.ServicesV1().Get(kubeRegistryConfiguration.KeyOfServiceInK8s, kubeRegistryConfiguration.KubeNamespace);
+            var endpoint = await kubeApi.EndPointsV1().Get(kubeRegistryConfiguration.KeyOfServiceInK8s, kubeRegistryConfiguration.KubeNamespace);
             var services = new List<Service>();
-            if (IsValid(service))
+            if (endpoint != null && endpoint.Subsets.Any())
             {
-                services.Add(BuildService(service));
+                services.AddRange(BuildServices(endpoint));
             }
             else
             {
@@ -38,25 +38,17 @@ namespace Ocelot.Provider.Kubernetes
             return services;
         }
 
-        private bool IsValid(ServiceV1 service)
+        private List<Service> BuildServices(EndpointsV1 endpoint)
         {
-            if (string.IsNullOrEmpty(service.Spec.ClusterIP) || service.Spec.Ports.Count <= 0)
+            var services = new List<Service>();
+
+            foreach (var subset in endpoint.Subsets)
             {
-                return false;
+                services.AddRange(subset.Addresses.Select(address => new Service(endpoint.Metadata.Name,
+                    new ServiceHostAndPort(address.Ip, subset.Ports.First().Port),
+                    endpoint.Metadata.Uid, string.Empty, Enumerable.Empty<string>())));
             }
-
-            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>());
+            return services;
         }
     }
 }
diff --git a/src/Ocelot.Provider.Kubernetes/Ocelot.Provider.Kubernetes.csproj b/src/Ocelot.Provider.Kubernetes/Ocelot.Provider.Kubernetes.csproj
index 980cd909..8f342865 100644
--- a/src/Ocelot.Provider.Kubernetes/Ocelot.Provider.Kubernetes.csproj
+++ b/src/Ocelot.Provider.Kubernetes/Ocelot.Provider.Kubernetes.csproj
@@ -28,8 +28,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="KubeClient" Version="2.3.4" />
-    <PackageReference Include="KubeClient.Extensions.DependencyInjection" Version="2.3.4" />
+    <PackageReference Include="KubeClient" Version="2.3.11" />
+    <PackageReference Include="KubeClient.Extensions.DependencyInjection" Version="2.3.11" />
   </ItemGroup>
 
   <ItemGroup>