Log an error when EvictPod method returns a non-nil error

End users should be able to see the detailed error from the EvictPod
method when it fails. Updates all strategies to log the error. The
PodLifeTime strategy already logs this error.

pkg/descheduler/strategies/duplicates.go

@@ -20,7 +20,7 @@ import (
 	"context"
 	"strings"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog"
 
@@ -49,6 +49,7 @@ func RemoveDuplicatePods(
 				// i = 0 does not evict the first pod
 				for i := 1; i < len(pods); i++ {
 					if _, err := podEvictor.EvictPod(ctx, pods[i], node); err != nil {
+						klog.Errorf("Error evicting pod: (%#v)", err)
 						break
 					}
 				}

pkg/descheduler/strategies/lownodeutilization.go

@@ -262,6 +262,7 @@ func evictPods(
 
 			success, err := podEvictor.EvictPod(ctx, pod, node)
 			if err != nil {
+				klog.Errorf("Error evicting pod: (%#v)", err)
 				break
 			}
 

pkg/descheduler/strategies/node_affinity.go

@@ -18,7 +18,8 @@ package strategies
 
 import (
 	"context"
-	"k8s.io/api/core/v1"
+
+	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog"
 
@@ -47,6 +48,7 @@ func RemovePodsViolatingNodeAffinity(ctx context.Context, client clientset.Inter
 						if !nodeutil.PodFitsCurrentNode(pod, node) && nodeutil.PodFitsAnyNode(pod, nodes) {
 							klog.V(1).Infof("Evicting pod: %v", pod.Name)
 							if _, err := podEvictor.EvictPod(ctx, pod, node); err != nil {
+								klog.Errorf("Error evicting pod: (%#v)", err)
 								break
 							}
 						}

pkg/descheduler/strategies/node_taint.go

@@ -18,12 +18,13 @@ package strategies
 
 import (
 	"context"
+
 	"sigs.k8s.io/descheduler/pkg/api"
 	"sigs.k8s.io/descheduler/pkg/descheduler/evictions"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
 	"sigs.k8s.io/descheduler/pkg/utils"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog"
 )
@@ -46,6 +47,7 @@ func RemovePodsViolatingNodeTaints(ctx context.Context, client clientset.Interfa
 			) {
 				klog.V(2).Infof("Not all taints with NoSchedule effect are tolerated after update for pod %v on node %v", pods[i].Name, node.Name)
 				if _, err := podEvictor.EvictPod(ctx, pods[i], node); err != nil {
+					klog.Errorf("Error evicting pod: (%#v)", err)
 					break
 				}
 			}

pkg/descheduler/strategies/pod_antiaffinity.go

@@ -42,6 +42,7 @@ func RemovePodsViolatingInterPodAntiAffinity(ctx context.Context, client clients
 			if checkPodsWithAntiAffinityExist(pods[i], pods) {
 				success, err := podEvictor.EvictPod(ctx, pods[i], node)
 				if err != nil {
+					klog.Errorf("Error evicting pod: (%#v)", err)
 					break
 				}
 

pkg/descheduler/strategies/toomanyrestarts.go

@@ -18,7 +18,8 @@ package strategies
 
 import (
 	"context"
-	"k8s.io/api/core/v1"
+
+	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog"
 
@@ -53,6 +54,7 @@ func RemovePodsHavingTooManyRestarts(ctx context.Context, client clientset.Inter
 				continue
 			}
 			if _, err := podEvictor.EvictPod(ctx, pods[i], node); err != nil {
+				klog.Errorf("Error evicting pod: (%#v)", err)
 				break
 			}
 		}