Restructure Project and Add Unit Tests

cmd/rename-pvc/main_test.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"github.com/spf13/cobra"
+	"io"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"testing"
+	"time"
+)
+
+type mockIOStreams struct {
+	In     io.Reader
+	Out    *bytes.Buffer
+	ErrOut *bytes.Buffer
+}
+
+func mockCommand(streams genericclioptions.IOStreams) *cobra.Command {
+	return &cobra.Command{
+		Use: "mock-rename-pvc",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// Simulate some work
+			time.Sleep(100 * time.Millisecond)
+			_, err := io.WriteString(streams.Out, "Mock command executed")
+			return err
+		},
+	}
+}
+
+func TestRun(t *testing.T) {
+	mockStreams := &mockIOStreams{
+		In:     &bytes.Buffer{},
+		Out:    &bytes.Buffer{},
+		ErrOut: &bytes.Buffer{},
+	}
+
+	mockRun := func() error {
+		cmd := mockCommand(genericclioptions.IOStreams{
+			In:     mockStreams.In,
+			Out:    mockStreams.Out,
+			ErrOut: mockStreams.ErrOut,
+		})
+		return cmd.Execute()
+	}
+
+	_, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	errCh := make(chan error, 1)
+	go func() {
+		errCh <- mockRun()
+	}()
+
+	time.Sleep(50 * time.Millisecond)
+
+	cancel()
+
+	select {
+	case err := <-errCh:
+		if err != nil && err != context.Canceled {
+			t.Errorf("run() returned an unexpected error: %v", err)
+		}
+	case <-time.After(1 * time.Second):
+		t.Error("run() did not complete within the expected time")
+	}
+
+	if !bytes.Contains(mockStreams.Out.Bytes(), []byte("Mock command executed")) {
+		t.Error("Expected output not found")
+	}
+}

pkg/renamepvc/execution.go

@@ -0,0 +1,110 @@
+package renamepvc
+
+import (
+	"context"
+	"fmt"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"time"
+)
+
+func (o *renamePVCOptions) execute(ctx context.Context) error {
+	oldPvc, err := o.k8sClient.CoreV1().PersistentVolumeClaims(o.sourceNamespace).Get(ctx, o.oldName, metav1.GetOptions{})
+	if err != nil {
+		return err
+	}
+
+	if err := o.checkIfMounted(ctx, oldPvc); err != nil {
+		return err
+	}
+
+	return o.rename(ctx, oldPvc)
+}
+
+// rename renames the PVC.
+func (o *renamePVCOptions) rename(ctx context.Context, oldPvc *corev1.PersistentVolumeClaim) error {
+	newPvc, err := o.createNewPVC(ctx, oldPvc)
+	if err != nil {
+		return fmt.Errorf("failed to create new PVC: %w", err)
+	}
+
+	pv, err := o.updatePVClaimRef(ctx, oldPvc, newPvc)
+	if err != nil {
+		return fmt.Errorf("failed to update PV claim ref: %w", err)
+	}
+
+	if err := o.waitUntilPvcIsBound(ctx, newPvc); err != nil {
+		return fmt.Errorf("failed to wait for PVC to be bound: %w", err)
+	}
+
+	if err := o.deleteOldPVC(ctx, oldPvc); err != nil {
+		return fmt.Errorf("failed to delete old PVC: %w", err)
+	}
+
+	o.printSuccess(newPvc, pv)
+	return nil
+}
+
+// waitUntilPvcIsBound waits until the new PVC is bound.
+func (o *renamePVCOptions) waitUntilPvcIsBound(ctx context.Context, pvc *corev1.PersistentVolumeClaim) error {
+	for i := 0; i < 60; i++ {
+		checkPVC, err := o.k8sClient.CoreV1().PersistentVolumeClaims(pvc.Namespace).Get(ctx, pvc.GetName(), metav1.GetOptions{})
+		if err != nil {
+			return err
+		}
+
+		if checkPVC.Status.Phase == corev1.ClaimBound {
+			return nil
+		}
+
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-time.After(time.Second):
+		}
+	}
+
+	return ErrNotBound
+}
+
+// createNewPVC creates a new PVC with the same spec as the old PVC but with a new name and namespace.
+func (o *renamePVCOptions) createNewPVC(ctx context.Context, oldPvc *corev1.PersistentVolumeClaim) (*corev1.PersistentVolumeClaim, error) {
+	newPvc := createNewPVC(oldPvc, o.newName, o.targetNamespace)
+	newPvc, err := o.k8sClient.CoreV1().PersistentVolumeClaims(o.targetNamespace).Create(ctx, newPvc, metav1.CreateOptions{})
+	if err != nil {
+		return nil, err
+	}
+	fmt.Fprintf(o.streams.Out, "New PVC with name '%s' created\n", newPvc.Name)
+	return newPvc, nil
+}
+
+// updatePVClaimRef updates the ClaimRef of the PV to the new PVC.
+func (o *renamePVCOptions) updatePVClaimRef(ctx context.Context, oldPvc, newPvc *corev1.PersistentVolumeClaim) (*corev1.PersistentVolume, error) {
+	pv, err := o.k8sClient.CoreV1().PersistentVolumes().Get(ctx, oldPvc.Spec.VolumeName, metav1.GetOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	pv.Spec.ClaimRef = createClaimRef(newPvc)
+	pv, err = o.k8sClient.CoreV1().PersistentVolumes().Update(ctx, pv, metav1.UpdateOptions{})
+	if err != nil {
+		return nil, err
+	}
+	fmt.Fprintf(o.streams.Out, "ClaimRef of PV '%s' is updated to new PVC '%s'\n", pv.Name, newPvc.Name)
+	return pv, nil
+}
+
+// deleteOldPVC deletes the old PVC.
+func (o *renamePVCOptions) deleteOldPVC(ctx context.Context, oldPvc *corev1.PersistentVolumeClaim) error {
+	err := o.k8sClient.CoreV1().PersistentVolumeClaims(o.sourceNamespace).Delete(ctx, oldPvc.Name, metav1.DeleteOptions{})
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(o.streams.Out, "Old PVC '%s' is deleted\n", oldPvc.Name)
+	return nil
+}
+
+// printSuccess prints a success message to the output stream.
+func (o *renamePVCOptions) printSuccess(newPvc *corev1.PersistentVolumeClaim, pv *corev1.PersistentVolume) {
+	fmt.Fprintf(o.streams.Out, "New PVC '%s' is bound to PV '%s'\n", newPvc.Name, pv.Name)
+}

pkg/renamepvc/helpers.go

@@ -0,0 +1,39 @@
+package renamepvc
+
+import (
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"k8s.io/client-go/kubernetes"
+)
+
+func getK8sClient(configFlags *genericclioptions.ConfigFlags) (*kubernetes.Clientset, error) {
+	config, err := configFlags.ToRESTConfig()
+	if err != nil {
+		return nil, err
+	}
+	return kubernetes.NewForConfig(config)
+}
+
+func createNewPVC(oldPvc *corev1.PersistentVolumeClaim, newName, targetNamespace string) *corev1.PersistentVolumeClaim {
+	newPvc := oldPvc.DeepCopy()
+	newPvc.Status = corev1.PersistentVolumeClaimStatus{}
+	newPvc.Name = newName
+	newPvc.UID = ""
+	newPvc.CreationTimestamp = metav1.Now()
+	newPvc.SelfLink = ""
+	newPvc.ResourceVersion = ""
+	newPvc.Namespace = targetNamespace
+	return newPvc
+}
+
+func createClaimRef(pvc *corev1.PersistentVolumeClaim) *corev1.ObjectReference {
+	return &corev1.ObjectReference{
+		Kind:            pvc.Kind,
+		Namespace:       pvc.Namespace,
+		Name:            pvc.Name,
+		UID:             pvc.UID,
+		APIVersion:      pvc.APIVersion,
+		ResourceVersion: pvc.ResourceVersion,
+	}
+}

pkg/renamepvc/options.go

@@ -0,0 +1,77 @@
+package renamepvc
+
+import (
+	"bufio"
+	"fmt"
+	"github.com/spf13/cobra"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"k8s.io/client-go/kubernetes"
+	"strings"
+)
+
+type renamePVCOptions struct {
+	streams     genericclioptions.IOStreams
+	configFlags *genericclioptions.ConfigFlags
+	k8sClient   kubernetes.Interface
+
+	confirm         bool
+	oldName         string
+	newName         string
+	sourceNamespace string
+	targetNamespace string
+}
+
+func (o *renamePVCOptions) complete(args []string) error {
+	var err error
+	o.oldName = args[0]
+	o.newName = args[1]
+
+	o.sourceNamespace, _, err = o.configFlags.ToRawKubeConfigLoader().Namespace()
+	if err != nil {
+		return err
+	}
+
+	if o.targetNamespace == "" {
+		o.targetNamespace = o.sourceNamespace
+	}
+
+	o.k8sClient, err = getK8sClient(o.configFlags)
+	return err
+}
+
+func (o *renamePVCOptions) validate() error {
+	if !o.confirm {
+		return o.confirmCheck()
+	}
+	return nil
+}
+
+func (o *renamePVCOptions) confirmCheck() error {
+	_, err := fmt.Fprintf(o.streams.Out,
+		"Rename PVC from '%s' in namespace '%s' to '%s' in namespace '%s'? (yes or no) ",
+		o.oldName, o.sourceNamespace, o.newName, o.targetNamespace)
+	if err != nil {
+		return err
+	}
+
+	input, err := bufio.NewReader(o.streams.In).ReadString('\n')
+	if err != nil {
+		return err
+	}
+
+	switch strings.TrimSpace(strings.ToLower(input)) {
+	case "y", "yes":
+		return nil
+	case "n", "no":
+		return ErrConfirmationNotSuccessful
+	default:
+		return ErrConfirmationUnknown
+	}
+}
+
+func (o *renamePVCOptions) addFlags(cmd *cobra.Command) {
+	cmd.Flags().BoolVarP(&o.confirm, "yes", "y", false, "Skips confirmation if flag is set")
+	cmd.Flags().StringVarP(&o.targetNamespace, "target-namespace", "N", "",
+		"Defines in which namespace the new PVC should be created. By default the source PVC's namespace is used.")
+	o.configFlags.AddFlags(cmd.Flags())
+}