NO-JIRA: Refactor get_coredns_config: Use DynamicClient & testify/suite

pkg/toolsets/netedge/coredns.go

@@ -4,13 +4,11 @@ import (
 	"fmt"
 
 	"github.com/containers/kubernetes-mcp-server/pkg/api"
-	"github.com/containers/kubernetes-mcp-server/pkg/kubernetes"
 	"github.com/google/jsonschema-go/jsonschema"
-	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/types"
-	"k8s.io/client-go/rest"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/utils/ptr"
-	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
 func initCoreDNS() []api.ServerTool {
@@ -34,30 +32,27 @@ func initCoreDNS() []api.ServerTool {
 	}
 }
 
-// newClientFunc is the function used to create a controller-runtime client.
-// It is a variable to allow overriding in tests.
-var newClientFunc = func(config *rest.Config, options client.Options) (client.Client, error) {
-	return client.New(config, options)
-}
-
 func getCoreDNSConfig(params api.ToolHandlerParams) (*api.ToolCallResult, error) {
-	cfg := params.RESTConfig()
-	if cfg == nil {
-		return api.NewToolCallResult("", fmt.Errorf("failed to get REST config")), nil
+	gvr := schema.GroupVersionResource{
+		Group:    "",
+		Version:  "v1",
+		Resource: "configmaps",
 	}
 
-	cl, err := newClientFunc(cfg, client.Options{Scheme: kubernetes.Scheme})
+	cm, err := params.DynamicClient().Resource(gvr).Namespace("openshift-dns").Get(params.Context, "dns-default", metav1.GetOptions{})
 	if err != nil {
-		return api.NewToolCallResult("", fmt.Errorf("failed to create controller-runtime client: %w", err)), nil
+		return api.NewToolCallResult("", fmt.Errorf("failed to get dns-default ConfigMap: %w", err)), nil
 	}
 
-	cm := &corev1.ConfigMap{}
-	err = cl.Get(params.Context, types.NamespacedName{Name: "dns-default", Namespace: "openshift-dns"}, cm)
+	data, found, err := unstructured.NestedStringMap(cm.Object, "data")
 	if err != nil {
-		return api.NewToolCallResult("", fmt.Errorf("failed to get dns-default ConfigMap: %w", err)), nil
+		return api.NewToolCallResult("", fmt.Errorf("failed to parse ConfigMap data: %w", err)), nil
+	}
+	if !found {
+		return api.NewToolCallResult("", fmt.Errorf("ConfigMap has no data")), nil
 	}
 
-	corefile, ok := cm.Data["Corefile"]
+	corefile, ok := data["Corefile"]
 	if !ok {
 		return api.NewToolCallResult("", fmt.Errorf("corefile not found in dns-default ConfigMap")), nil
 	}

pkg/toolsets/netedge/coredns_test.go

@@ -4,9 +4,8 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/client-go/rest"
-	"sigs.k8s.io/controller-runtime/pkg/client"
-	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"k8s.io/client-go/dynamic/fake"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 )
 
 func (s *NetEdgeTestSuite) TestGetCoreDNSConfig() {
@@ -54,6 +53,18 @@ func (s *NetEdgeTestSuite) TestGetCoreDNSConfig() {
 			expectError:    true,
 			errorContains:  "corefile not found",
 		},
+		{
+			name: "failure - data not found",
+			configMap: &corev1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "dns-default",
+					Namespace: "openshift-dns",
+				},
+			},
+			expectedOutput: "",
+			expectError:    true,
+			errorContains:  "ConfigMap has no data",
+		},
 	}
 
 	for _, tt := range tests {
@@ -64,13 +75,14 @@ func (s *NetEdgeTestSuite) TestGetCoreDNSConfig() {
 				objs = append(objs, tt.configMap)
 			}
 
-			// Override newClientFunc to return fake client
-			originalNewClientFunc := newClientFunc
-			defer func() { newClientFunc = originalNewClientFunc }()
+			// Setup fake dynamic client
+			scheme := runtime.NewScheme()
+			err := clientgoscheme.AddToScheme(scheme)
+			s.Require().NoError(err)
 
-			newClientFunc = func(config *rest.Config, options client.Options) (client.Client, error) {
-				return fake.NewClientBuilder().WithRuntimeObjects(objs...).Build(), nil
-			}
+			// Create a fake dynamic client with the objects
+			dynClient := fake.NewSimpleDynamicClient(scheme, objs...)
+			s.SetDynamicClient(dynClient)
 
 			// Call handler using suite params
 			result, err := getCoreDNSConfig(s.params)