RFE-5434: Add cluster ID and timestamp to must-gather directory name

go.mod

@@ -67,7 +67,7 @@ require (
 	k8s.io/klog/v2 v2.140.0
 	k8s.io/kubectl v0.35.2
 	k8s.io/pod-security-admission v0.35.2
-	k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2
+	k8s.io/utils v0.0.0-20260507154919-ff6756f316d2
 	sigs.k8s.io/yaml v1.6.0
 )
 

go.sum

@@ -614,8 +614,8 @@ k8s.io/metrics v0.35.2 h1:PJRP88qeadR5evg4ZKJAh3NR3ICchwM51/Aidd0LHjc=
 k8s.io/metrics v0.35.2/go.mod h1:w1pJmSu2j8ftVI26MGcJtMnpmZ06oKwb4Enm+xVl06Q=
 k8s.io/pod-security-admission v0.35.2 h1:vzEfL/TpdwwIE25xQiamiRfmWD+FIcNXJYzoMI50AUY=
 k8s.io/pod-security-admission v0.35.2/go.mod h1:zrNF0GSYasCR8SHiAD67q2iUTHitVoFQRvTOy/UijyU=
-k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2 h1:AZYQSJemyQB5eRxqcPky+/7EdBj0xi3g0ZcxxJ7vbWU=
-k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2/go.mod h1:xDxuJ0whA3d0I4mf/C4ppKHxXynQ+fxnkmQH0vTHnuk=
+k8s.io/utils v0.0.0-20260507154919-ff6756f316d2 h1:wU4tMEhLGgIbLvXQb1cfN+EcM0wf7zC6CPF+C79jroc=
+k8s.io/utils v0.0.0-20260507154919-ff6756f316d2/go.mod h1:xDxuJ0whA3d0I4mf/C4ppKHxXynQ+fxnkmQH0vTHnuk=
 sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 h1:IpInykpT6ceI+QxKBbEflcR5EXP7sU1kvOlxwZh5txg=
 sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730/go.mod h1:mdzfpAEoE6DHQEN0uh9ZbOCuHbLK5wOm7dK4ctXE9Tg=
 sigs.k8s.io/kube-storage-version-migrator v0.0.6-0.20230721195810-5c8923c5ff96 h1:PFWFSkpArPNJxFX4ZKWAk9NSeRoZaXschn+ULa4xVek=

pkg/cli/admin/mustgather/mustgather.go

@@ -41,6 +41,7 @@ import (
 	"k8s.io/kubectl/pkg/scheme"
 	"k8s.io/kubectl/pkg/util/templates"
 	admissionapi "k8s.io/pod-security-admission/api"
+	"k8s.io/utils/clock"
 	"k8s.io/utils/exec"
 	utilptr "k8s.io/utils/ptr"
 
@@ -73,7 +74,9 @@ var (
 	`)
 
 	mustGatherExample = templates.Examples(`
-		# Gather information using the default plug-in image and command, writing into ./must-gather.local.<rand>
+		# Gather information using the default plug-in image and command, writing into
+		# ./must-gather.local.<cluster-id-suffix>.<timestamp(UTC)>.<rand>
+		# or ./must-gather.local.<timestamp(UTC)>.<rand> if the cluster ID is unavailable
 		  oc adm must-gather
 
 		# Gather information with a specific local folder to copy to
@@ -230,7 +233,7 @@ func (o *MustGatherOptions) Complete(f kcmdutil.Factory, cmd *cobra.Command, arg
 		}
 	}
 	if len(o.DestDir) == 0 {
-		o.DestDir = fmt.Sprintf("must-gather.local.%06d", rand.Int63())
+		o.DestDir = o.generateDestDir()
 	}
 	// TODO: this should be in Validate() method, but added here because of the call to o.completeImages() below
 	if o.AllImages {
@@ -266,6 +269,51 @@ func (o *MustGatherOptions) Complete(f kcmdutil.Factory, cmd *cobra.Command, arg
 	return nil
 }
 
+// getClock returns the injected PassiveClock, defaulting to clock.RealClock{} when unset.
+func (o *MustGatherOptions) getClock() clock.PassiveClock {
+	if o.clock != nil {
+		return o.clock
+	}
+	return clock.RealClock{}
+}
+
+// generateDestDir builds the default destination directory name for must-gather output.
+// The format includes a partial cluster ID (last 12 characters), a UTC timestamp, and a
+// random ID to help distinguish must-gather archives from different clusters and collection
+// times. If the cluster ID cannot be retrieved (e.g. cluster is unreachable), it falls back
+// to the timestamp and random ID only.
+func (o *MustGatherOptions) generateDestDir() string {
+	parts := []string{"must-gather.local"}
+
+	if clusterID := o.getClusterIDSuffix(); clusterID != "" {
+		parts = append(parts, clusterID)
+	}
+
+	timestamp := o.getClock().Now().UTC().Format("20060102T150405Z")
+	parts = append(parts, timestamp)
+
+	parts = append(parts, fmt.Sprintf("%06d", rand.Int63()))
+
+	return strings.Join(parts, ".")
+}
+
+func (o *MustGatherOptions) getClusterIDSuffix() string {
+	lookupCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	cv, err := o.ConfigClient.ConfigV1().ClusterVersions().Get(lookupCtx, "version", metav1.GetOptions{})
+	if err != nil {
+		klog.V(4).Infof("unable to retrieve cluster ID for directory name: %v", err)
+		return ""
+	}
+
+	id := string(cv.Spec.ClusterID)
+	if length := len(id); length > 12 {
+		return id[length-12:]
+	}
+	return id
+}
+
 func (o *MustGatherOptions) completeImages(ctx context.Context) error {
 	for _, imageStream := range o.ImageStreams {
 		if image, err := o.resolveImageStreamTagString(ctx, imageStream); err == nil {
@@ -398,6 +446,7 @@ type MustGatherOptions struct {
 	SinceTime        string
 
 	RsyncRshCmd string
+	clock       clock.PassiveClock
 
 	PrinterCreated printers.ResourcePrinter
 	PrinterDeleted printers.ResourcePrinter

pkg/cli/admin/mustgather/mustgather_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"path"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
@@ -20,6 +21,7 @@ import (
 	"k8s.io/cli-runtime/pkg/printers"
 	dynamicfake "k8s.io/client-go/dynamic/fake"
 	"k8s.io/client-go/kubernetes/fake"
+	clocktesting "k8s.io/utils/clock/testing"
 	"k8s.io/utils/diff"
 
 	configv1 "github.com/openshift/api/config/v1"
@@ -28,6 +30,57 @@ import (
 	imageclient "github.com/openshift/client-go/image/clientset/versioned/fake"
 )
 
+func TestGenerateDestDir(t *testing.T) {
+	fixedTime := time.Date(2026, 4, 14, 12, 0, 0, 0, time.UTC)
+	fc := clocktesting.NewFakePassiveClock(fixedTime)
+
+	tests := []struct {
+		name           string
+		clusterID      string
+		expectedPrefix string
+	}{
+		{
+			name:           "with full cluster ID includes last 12 chars",
+			clusterID:      "0194fffc-f70a-4776-b00d-76708af6b91c",
+			expectedPrefix: "must-gather.local.76708af6b91c.20260414T120000Z.",
+		},
+		{
+			name:           "with short cluster ID uses full ID",
+			clusterID:      "abcdef",
+			expectedPrefix: "must-gather.local.abcdef.20260414T120000Z.",
+		},
+		{
+			name:           "without cluster ID falls back gracefully",
+			expectedPrefix: "must-gather.local.20260414T120000Z.",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			var configObjects []runtime.Object
+			if tc.clusterID != "" {
+				configObjects = []runtime.Object{
+					&configv1.ClusterVersion{
+						ObjectMeta: metav1.ObjectMeta{Name: "version"},
+						Spec: configv1.ClusterVersionSpec{
+							ClusterID: configv1.ClusterID(tc.clusterID),
+						},
+					},
+				}
+			}
+			options := MustGatherOptions{
+				IOStreams:    genericiooptions.NewTestIOStreamsDiscard(),
+				ConfigClient: configv1fake.NewSimpleClientset(configObjects...),
+				clock:        fc,
+			}
+			destDir := options.generateDestDir()
+			if !strings.HasPrefix(destDir, tc.expectedPrefix) {
+				t.Errorf("expected prefix %q, got %q", tc.expectedPrefix, destDir)
+			}
+		})
+	}
+}
+
 func TestImagesAndImageStreams(t *testing.T) {
 
 	testCases := []struct {