add PollingKubeServiceDiscovery

src/Ocelot.Provider.Kubernetes/KubernetesProviderFactory.cs

@@ -33,6 +33,10 @@ namespace Ocelot.Provider.Kubernetes
 
             var k8sServiceDiscoveryProvider = new Kube(k8sRegistryConfiguration, factory, kubeClientFactory);
 
+            if (config.Type?.ToLower() == "pollkube")
+            {
+                return new PollKube(config.PollingInterval, factory, k8sServiceDiscoveryProvider);
+            }
             return k8sServiceDiscoveryProvider;
         }
     }

src/Ocelot.Provider.Kubernetes/PollKube.cs

@@ -0,0 +1,50 @@
+using Ocelot.Logging;
+using Ocelot.ServiceDiscovery.Providers;
+using Ocelot.Values;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Ocelot.Provider.Kubernetes
+{
+    public class PollKube : IServiceDiscoveryProvider
+    {
+        private readonly IOcelotLogger _logger;
+        private readonly IServiceDiscoveryProvider _kubeServiceDiscoveryProvider;
+        private readonly Timer _timer;
+        private bool _polling;
+        private List<Service> _services;
+
+        public PollKube(int pollingInterval, IOcelotLoggerFactory factory, IServiceDiscoveryProvider kubeServiceDiscoveryProvider)
+        {
+            _logger = factory.CreateLogger<PollKube>();
+            _kubeServiceDiscoveryProvider = kubeServiceDiscoveryProvider;
+            _services = new List<Service>();
+
+            _timer = new Timer(async x =>
+            {
+                if (_polling)
+                {
+                    return;
+                }
+
+                _polling = true;
+                await Poll();
+                _polling = false;
+            }, null, pollingInterval, pollingInterval);
+        }
+
+        public Task<List<Service>> Get()
+        {
+            return Task.FromResult(_services);
+        }
+
+        private async Task Poll()
+        {
+            _services = await _kubeServiceDiscoveryProvider.Get();
+        }
+    }
+}
+