Merge pull request #137543 from kfess/bugfix/disable-eviction-dry-run

Fix: kubectl drain --disable-eviction --dry-run=server hanging indefinitely

Kubernetes-commit: 47f990437458a2b171f51b5e97a0c28c81d949d1

go.mod

@@ -30,7 +30,7 @@ require (
 	golang.org/x/sys v0.43.0
 	golang.org/x/text v0.36.0
 	gopkg.in/evanphx/json-patch.v4 v4.13.0
-	k8s.io/api v0.0.0-20260504204501-f40e8ff20019
+	k8s.io/api v0.0.0-20260505124447-9279b4068be3
 	k8s.io/apimachinery v0.0.0-20260504204121-2fca5de43c56
 	k8s.io/cli-runtime v0.0.0-20260504213337-8858f6b36386
 	k8s.io/client-go v0.0.0-20260504205003-535f2d0806f7

go.sum

@@ -205,8 +205,8 @@ gopkg.in/inf.v0 v0.9.1/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-k8s.io/api v0.0.0-20260504204501-f40e8ff20019 h1:ldAUH3G96shgtYJbZwndQTKhRAMZ2dDrkC7Pw0u15uM=
-k8s.io/api v0.0.0-20260504204501-f40e8ff20019/go.mod h1:3USlyQsXhfXGbJzZevPnCx4ZCGaYM/xzUYOlYcB/eUE=
+k8s.io/api v0.0.0-20260505124447-9279b4068be3 h1:DhwY3OTw7UCwd88KVVm2jbnPFLTRy27ZvMSI2MBPGFk=
+k8s.io/api v0.0.0-20260505124447-9279b4068be3/go.mod h1:3USlyQsXhfXGbJzZevPnCx4ZCGaYM/xzUYOlYcB/eUE=
 k8s.io/apimachinery v0.0.0-20260504204121-2fca5de43c56 h1:JN0n7OEc9lF1Rnk+09tWPA9FC2v7+wxxR+3lgBo4uNU=
 k8s.io/apimachinery v0.0.0-20260504204121-2fca5de43c56/go.mod h1:VERTuh5iDSri6+w9SKXTmWbqrGWrdBWrNaC/gYIcRTY=
 k8s.io/cli-runtime v0.0.0-20260504213337-8858f6b36386 h1:71wIHWEqonNQNCV4fZUZfNy85N1fvFW7jw2Xc7DVk1A=

pkg/drain/drain.go

@@ -390,10 +390,18 @@ func (d *Helper) deletePods(pods []corev1.Pod, getPodFn func(namespace, name str
 		if err != nil && !apierrors.IsNotFound(err) {
 			return err
 		}
+		if d.DryRunStrategy == cmdutil.DryRunServer {
+			continue
+		}
 		if d.OnPodDeletionOrEvictionStarted != nil {
 			d.OnPodDeletionOrEvictionStarted(&pod, false)
 		}
 	}
+
+	if d.DryRunStrategy == cmdutil.DryRunServer {
+		return nil
+	}
+
 	ctx := d.getContext()
 	params := waitForDeleteParams{
 		ctx:                             ctx,

pkg/drain/drain_test.go

@@ -17,12 +17,14 @@ limitations under the License.
 package drain
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
 	"math"
 	"os"
 	"reflect"
+	"slices"
 	"sort"
 	"strconv"
 	"testing"
@@ -38,6 +40,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes/fake"
 	ktest "k8s.io/client-go/testing"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 )
 
 func TestDeletePods(t *testing.T) {
@@ -461,6 +464,66 @@ func TestDeleteOrEvict(t *testing.T) {
 	}
 }
 
+func TestDeleteOrEvictWithDryRunServer(t *testing.T) {
+	testCases := []struct {
+		description     string
+		disableEviction bool
+	}{
+		{
+			description:     "Eviction enabled with server dry-run",
+			disableEviction: false,
+		},
+		{
+			description:     "Eviction disabled with server dry-run",
+			disableEviction: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			var buf bytes.Buffer
+			h := &Helper{
+				Out:                &buf,
+				GracePeriodSeconds: 10,
+				DisableEviction:    tc.disableEviction,
+				DryRunStrategy:     cmdutil.DryRunServer,
+			}
+
+			var allPods []runtime.Object
+			var podsToDelete []corev1.Pod
+
+			for i := 1; i <= 2; i++ {
+				pod := corev1.Pod{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      fmt.Sprintf("mypod-%d", i),
+						Namespace: "default",
+					},
+				}
+				allPods = append(allPods, &pod)
+				podsToDelete = append(podsToDelete, pod)
+			}
+
+			k := fake.NewSimpleClientset(allPods...)
+
+			// This reactor intercepts delete requests with DryRun set and returns success without
+			// removing the object, simulating real API server dry-run behavior.
+			k.PrependReactor("delete", "pods", func(actions ktest.Action) (bool, runtime.Object, error) {
+				deleteAction := actions.(ktest.DeleteAction)
+				if slices.Contains(deleteAction.GetDeleteOptions().DryRun, metav1.DryRunAll) {
+					return true, nil, nil
+				}
+				return false, nil, nil
+			})
+			addEvictionSupport(t, k, "v1")
+			h.Client = k
+
+			if err := h.DeleteOrEvictPods(podsToDelete); err != nil {
+				t.Fatalf("error from DeleteOrEvictPods: %v", err)
+			}
+		})
+	}
+}
+
 func mockFilterSkip(_ corev1.Pod) PodDeleteStatus {
 	return MakePodDeleteStatusSkip()
 }