Remove requirement for certificate authority and certificate authority data in kubeconfig. (#222)

* Remove requirement for certificate authority data in kubeconfig.

* Update src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

Update casing of `URL` at @itowlson suggestion.

Co-Authored-By: twitchax <twitchax@gmail.com>

src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

@@ -155,31 +155,23 @@ namespace k8s
 
             if (clusterDetails?.ClusterEndpoint == null)
             {
-                throw new KubeConfigException($"Cluster not found for context {activeContext} in kubeconfig");
+                throw new KubeConfigException($"Cluster not found for context `{activeContext}` in kubeconfig");
             }
-
             if (string.IsNullOrWhiteSpace(clusterDetails.ClusterEndpoint.Server))
             {
-                throw new KubeConfigException($"Server not found for current-context {activeContext} in kubeconfig");
+                throw new KubeConfigException($"Server not found for current-context `{activeContext}` in kubeconfig");
             }
-            Host = clusterDetails.ClusterEndpoint.Server;
 
+            Host = clusterDetails.ClusterEndpoint.Server;
             SkipTlsVerify = clusterDetails.ClusterEndpoint.SkipTlsVerify;
 
-            try
+            if(!Uri.TryCreate(Host, UriKind.Absolute, out Uri uri))
             {
-                var uri = new Uri(Host);
+                throw new KubeConfigException($"Bad server host URL `{Host}` (cannot be parsed)");
-                if (uri.Scheme == "https")
-                {
-                    // check certificate for https
-                    if (!clusterDetails.ClusterEndpoint.SkipTlsVerify &&
-                        string.IsNullOrWhiteSpace(clusterDetails.ClusterEndpoint.CertificateAuthorityData) &&
-                        string.IsNullOrWhiteSpace(clusterDetails.ClusterEndpoint.CertificateAuthority))
-                    {
-                        throw new KubeConfigException(
-                            $"neither certificate-authority-data nor certificate-authority not found for current-context :{activeContext} in kubeconfig");
             }
             
+            if (uri.Scheme == "https")
+            {
                 if (!string.IsNullOrEmpty(clusterDetails.ClusterEndpoint.CertificateAuthorityData))
                 {
                     var data = clusterDetails.ClusterEndpoint.CertificateAuthorityData;
@@ -191,11 +183,6 @@ namespace k8s
                 }
             }
         }
-            catch (UriFormatException e)
-            {
-                throw new KubeConfigException("Bad Server host url", e);
-            }
-        }
 
         private void SetUserDetails(K8SConfiguration k8SConfig, Context activeContext)
         {

tests/KubernetesClient.Tests/KubernetesClientConfigurationTests.cs

@@ -70,17 +70,6 @@ namespace k8s.Tests
             Assert.Equal(File.ReadAllText("assets/client-key-data.txt"), cfg.ClientCertificateKeyData);
         }
 
-        /// <summary>
-        ///     Checks that a KubeConfigException is thrown when no certificate-authority-data is set and user do not require tls
-        ///     skip
-        /// </summary>
-        [Fact]
-        public void CheckClusterTlsCorrectness()
-        {
-            var fi = new FileInfo("assets/kubeconfig.tls-no-skip-error.yml");
-            Assert.Throws<KubeConfigException>(() => KubernetesClientConfiguration.BuildConfigFromConfigFile(fi));
-        }
-
         /// <summary>
         ///     Checks that a KubeConfigException is thrown when no certificate-authority-data is set and user do not require tls
         ///     skip

tests/KubernetesClient.Tests/assets/kubeconfig.tls-no-skip-error.yml

@@ -1,25 +0,0 @@
-# Sample file based on https://kubernetes.io/docs/tasks/access-application-cluster/authenticate-across-clusters-kubeconfig/
-# WARNING: File includes minor fixes
----
-current-context: federal-context
-apiVersion: v1
-clusters:
-- cluster:
-    server: http://cow.org:8080
-  name: cow-cluster
-- cluster:
-    # certificate-authority: path/to/my/cafile
-    server: https://horse.org:4443
-  name: horse-cluster
-contexts:
-- context:
-    cluster: horse-cluster
-    namespace: chisel-ns
-    user: green-user
-  name: federal-context
-kind: Config
-users:
-- name: green-user
-  user:
-    client-certificate: assets/client.crt
-    client-key: assets/client.key