feat: add namespace subcommand

cmd/namespace.go

@@ -0,0 +1,93 @@
+package cmd
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+
+	"github.com/AlecAivazis/survey/v2"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+// namespaceCmd represents the command to change Kubernetes namespaces.
+var namespaceCmd = &cobra.Command{
+	Use:     "namespace",
+	Aliases: []string{"ns"}, // Add this line to define the alias
+	Short:   "Switch the active Kubernetes namespace",
+	Args:    cobra.MaximumNArgs(1), // Accept at most one argument (the namespace name)
+	Run: func(cmd *cobra.Command, args []string) {
+		// Determine the location of the kubeconfig file
+		kubeconfigPath := os.Getenv("KUBECONFIG")
+		if kubeconfigPath == "" {
+			homeDir, err := os.UserHomeDir()
+			if err != nil {
+				log.Fatalf("Failed to determine home directory: %v", err)
+			}
+			kubeconfigPath = filepath.Join(homeDir, ".kube", "config")
+		}
+
+		// Build the Kubernetes client configuration
+		config, err := clientcmd.BuildConfigFromFlags("", kubeconfigPath)
+		if err != nil {
+			log.Fatalf("Error building kubeconfig: %v", err)
+		}
+
+		// Create the Kubernetes clientset
+		clientset, err := kubernetes.NewForConfig(config)
+		if err != nil {
+			log.Fatalf("Error creating Kubernetes client: %v", err)
+		}
+
+		// Get all namespaces
+		var namespaceNames []string
+		namespaces, err := clientset.CoreV1().Namespaces().List(context.TODO(), metav1.ListOptions{})
+		for _, ns := range namespaces.Items {
+			namespaceNames = append(namespaceNames, ns.Name)
+		}
+		if err != nil {
+			log.Fatalf("Error listing namespaces: %v", err)
+		}
+
+		// Determine the target namespace
+		var selectedNamespace string
+		if len(args) == 1 {
+			// Non-interactive mode: use the provided ma,es[ace] name
+			selectedNamespace = args[0]
+		} else {
+			// Interactive mode: show list of clusters
+			prompt := &survey.Select{
+				Message: "Choose a namespace:",
+				Options: namespaceNames,
+			}
+			err = survey.AskOne(prompt, &selectedNamespace)
+			if err != nil {
+				log.Fatalf("Failed to get user input: %v", err)
+			}
+		}
+
+		// Load the kubeconfig file
+		kubeconfig, err := clientcmd.LoadFromFile(kubeconfigPath)
+		if err != nil {
+			log.WithFields(log.Fields{"source": kubeconfigPath}).Fatalf("Failed to parse kubeconfig file: %v", err)
+		}
+
+		// Update the kubeconfig
+		kubeconfig.Contexts[kubeconfig.CurrentContext].Namespace = selectedNamespace
+
+		// Write the updated kubeconfig back to the file
+		err = clientcmd.WriteToFile(*kubeconfig, kubeconfigPath)
+		if err != nil {
+			log.Fatalf("Error writing kubeconfig file: %v", err)
+		}
+
+		log.Infof("Switched to namespace '%s'", selectedNamespace)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(namespaceCmd)
+}