feat(kubernetes): pods_get for explicit or nil namespace

Author: manusa

pkg/kubernetes/configuration.go

@@ -1,25 +1,23 @@
 package kubernetes
 
 import (
-	"k8s.io/client-go/tools/clientcmd"
 	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
 	"k8s.io/client-go/tools/clientcmd/api/latest"
 )
 
 func ConfigurationView() (string, error) {
 	// TODO: consider in cluster run mode (current approach only shows kubeconfig)
-	pathOptions := clientcmd.NewDefaultPathOptions()
-	cfg, err := pathOptions.GetStartingConfig()
+	cfg, err := resolveConfig().RawConfig()
 	if err != nil {
 		return "", err
 	}
-	if err = clientcmdapi.MinifyConfig(cfg); err != nil {
+	if err = clientcmdapi.MinifyConfig(&cfg); err != nil {
 		return "", err
 	}
-	if err = clientcmdapi.FlattenConfig(cfg); err != nil {
+	if err = clientcmdapi.FlattenConfig(&cfg); err != nil {
 		return "", err
 	}
-	convertedObj, err := latest.Scheme.ConvertToVersion(cfg, latest.ExternalVersion)
+	convertedObj, err := latest.Scheme.ConvertToVersion(&cfg, latest.ExternalVersion)
 	if err != nil {
 		return "", err
 	}

pkg/kubernetes/kubernetes.go

@@ -5,6 +5,7 @@ import (
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/restmapper"
 	"k8s.io/client-go/tools/clientcmd"
+	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
 	"sigs.k8s.io/yaml"
 )
 
@@ -37,11 +38,28 @@ func marshal(v any) (string, error) {
 	return string(ret), nil
 }
 
+func resolveConfig() clientcmd.ClientConfig {
+	pathOptions := clientcmd.NewDefaultPathOptions()
+	//cfg, err := pathOptions.GetStartingConfig()
+	//if err != nil {
+	//	return nil, err
+	//}
+	//if err = clientcmdapi.MinifyConfig(cfg); err != nil {
+	//	return nil, err
+	//}
+	//if err = clientcmdapi.FlattenConfig(cfg); err != nil {
+	//	return nil, err
+	//}
+	//return cfg, nil
+	return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		&clientcmd.ClientConfigLoadingRules{ExplicitPath: pathOptions.GetDefaultFilename()},
+		&clientcmd.ConfigOverrides{ClusterInfo: clientcmdapi.Cluster{Server: ""}})
+}
+
 func resolveClientConfig() (*rest.Config, error) {
 	inClusterConfig, err := rest.InClusterConfig()
 	if err == nil && inClusterConfig != nil {
 		return inClusterConfig, nil
 	}
-	pathOptions := clientcmd.NewDefaultPathOptions()
-	return clientcmd.BuildConfigFromFlags("", pathOptions.GetDefaultFilename())
+	return resolveConfig().ClientConfig()
 }

pkg/kubernetes/pods.go

@@ -16,3 +16,14 @@ func (k *Kubernetes) PodsListInNamespace(ctx context.Context, namespace string)
 		Group: "", Version: "v1", Kind: "Pod",
 	}, namespace)
 }
+
+func (k *Kubernetes) PodsGet(ctx context.Context, namespace, name string) (string, error) {
+	if namespace == "" {
+		if ns, _, nsErr := resolveConfig().Namespace(); nsErr == nil {
+			namespace = ns
+		}
+	}
+	return k.ResourcesGet(ctx, &schema.GroupVersionKind{
+		Group: "", Version: "v1", Kind: "Pod",
+	}, namespace, name)
+}

pkg/kubernetes/resources.go

@@ -27,6 +27,22 @@ func (k *Kubernetes) ResourcesList(ctx context.Context, gvk *schema.GroupVersion
 	return marshal(rl.Items)
 }
 
+func (k *Kubernetes) ResourcesGet(ctx context.Context, gvk *schema.GroupVersionKind, namespace, name string) (string, error) {
+	client, err := dynamic.NewForConfig(k.cfg)
+	if err != nil {
+		return "", err
+	}
+	gvr, err := k.resourceFor(gvk)
+	if err != nil {
+		return "", err
+	}
+	rg, err := client.Resource(*gvr).Namespace(namespace).Get(ctx, name, metav1.GetOptions{})
+	if err != nil {
+		return "", err
+	}
+	return marshal(rg)
+}
+
 func (k *Kubernetes) resourceFor(gvk *schema.GroupVersionKind) (*schema.GroupVersionResource, error) {
 	if k.deferredDiscoveryRESTMapper == nil {
 		d, err := discovery.NewDiscoveryClientForConfig(k.cfg)

pkg/mcp/common_test.go

@@ -6,6 +6,8 @@ import (
 	"github.com/mark3labs/mcp-go/mcp"
 	"github.com/mark3labs/mcp-go/server"
 	"github.com/spf13/afero"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -55,6 +57,8 @@ func TestMain(m *testing.M) {
 		BinaryAssetsDirectory: filepath.Join(envTestDir, "k8s", versionDir),
 	}
 	envTestRestConfig, _ = envTest.Start()
+	kc, _ := kubernetes.NewForConfig(envTestRestConfig)
+	createTestData(context.Background(), kc)
 
 	// Test!
 	code := m.Run()
@@ -111,6 +115,7 @@ func testCase(t *testing.T, test func(c *mcpContext)) {
 	test(mcpCtx)
 }
 
+// withKubeConfig sets up a fake kubeconfig in the temp directory based on the provided rest.Config
 func (c *mcpContext) withKubeConfig(rc *rest.Config) *api.Config {
 	fakeConfig := api.NewConfig()
 	fakeConfig.CurrentContext = "fake-context"
@@ -132,10 +137,12 @@ func (c *mcpContext) withKubeConfig(rc *rest.Config) *api.Config {
 	return fakeConfig
 }
 
+// withEnvTest sets up the environment for kubeconfig to be used with envTest
 func (c *mcpContext) withEnvTest() {
 	c.withKubeConfig(envTestRestConfig)
 }
 
+// newKubernetesClient creates a new Kubernetes client with the current kubeconfig
 func (c *mcpContext) newKubernetesClient() *kubernetes.Clientset {
 	c.withEnvTest()
 	pathOptions := clientcmd.NewDefaultPathOptions()
@@ -147,9 +154,44 @@ func (c *mcpContext) newKubernetesClient() *kubernetes.Clientset {
 	return kubernetesClient
 }
 
+// callTool helper function to call a tool by name with arguments
 func (c *mcpContext) callTool(name string, args map[string]interface{}) (*mcp.CallToolResult, error) {
 	callToolRequest := mcp.CallToolRequest{}
 	callToolRequest.Params.Name = name
 	callToolRequest.Params.Arguments = args
 	return c.mcpClient.CallTool(c.ctx, callToolRequest)
 }
+
+func createTestData(ctx context.Context, kc *kubernetes.Clientset) {
+	_, _ = kc.CoreV1().Namespaces().
+		Create(ctx, &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: "ns-1"}}, metav1.CreateOptions{})
+	_, _ = kc.CoreV1().Namespaces().
+		Create(ctx, &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: "ns-2"}}, metav1.CreateOptions{})
+	_, _ = kc.CoreV1().Pods("default").
+		Create(ctx, &corev1.Pod{
+			ObjectMeta: metav1.ObjectMeta{Name: "a-pod-in-default"},
+			Spec: corev1.PodSpec{
+				Containers: []corev1.Container{
+					{Name: "nginx", Image: "nginx"},
+				},
+			},
+		}, metav1.CreateOptions{})
+	_, _ = kc.CoreV1().Pods("ns-1").
+		Create(ctx, &corev1.Pod{
+			ObjectMeta: metav1.ObjectMeta{Name: "a-pod-in-ns-1"},
+			Spec: corev1.PodSpec{
+				Containers: []corev1.Container{
+					{Name: "nginx", Image: "nginx"},
+				},
+			},
+		}, metav1.CreateOptions{})
+	_, _ = kc.CoreV1().Pods("ns-2").
+		Create(ctx, &corev1.Pod{
+			ObjectMeta: metav1.ObjectMeta{Name: "a-pod-in-ns-2"},
+			Spec: corev1.PodSpec{
+				Containers: []corev1.Container{
+					{Name: "nginx", Image: "nginx"},
+				},
+			},
+		}, metav1.CreateOptions{})
+}

pkg/mcp/pods.go

@@ -21,6 +21,17 @@ func (s *Sever) initPods() {
 			mcp.Required(),
 		),
 	), podsListInNamespace)
+	s.server.AddTool(mcp.NewTool(
+		"pods_get",
+		mcp.WithDescription("Get a Kubernetes Pod in the current namespace with the provided name"),
+		mcp.WithString("namespace",
+			mcp.Description("Namespace to get the Pod from"),
+		),
+		mcp.WithString("name",
+			mcp.Description("Name of the Pod"),
+			mcp.Required(),
+		),
+	), podsGet)
 }
 
 func podsListInAllNamespaces(ctx context.Context, _ mcp.CallToolRequest) (*mcp.CallToolResult, error) {
@@ -50,3 +61,23 @@ func podsListInNamespace(ctx context.Context, ctr mcp.CallToolRequest) (*mcp.Cal
 	}
 	return NewTextResult(ret, err), nil
 }
+
+func podsGet(ctx context.Context, ctr mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	k, err := kubernetes.NewKubernetes()
+	if err != nil {
+		return NewTextResult("", fmt.Errorf("failed to get pod: %v", err)), nil
+	}
+	ns := ctr.Params.Arguments["namespace"]
+	if ns == nil {
+		ns = ""
+	}
+	name := ctr.Params.Arguments["name"]
+	if name == nil {
+		return NewTextResult("", errors.New("failed to get pod, missing argument name")), nil
+	}
+	ret, err := k.PodsGet(ctx, ns.(string), name.(string))
+	if err != nil {
+		return NewTextResult("", fmt.Errorf("failed to get pod %s in namespace %s: %v", name, ns, err)), nil
+	}
+	return NewTextResult(ret, err), nil
+}