refactor(controller): optimize PDB creation request (#12974)

Signed-off-by: Anton Gilgur <agilgur5@gmail.com>

workflow/controller/operator.go

@@ -3741,38 +3741,30 @@ func (woc *wfOperationCtx) createPDBResource(ctx context.Context) error {
 		return nil
 	}
 
-	pdb, err := woc.controller.kubeclientset.PolicyV1().PodDisruptionBudgets(woc.wf.Namespace).Get(
-		ctx,
-		woc.wf.Name,
-		metav1.GetOptions{},
-	)
-	if err != nil && !apierr.IsNotFound(err) && !apierr.IsAlreadyExists(err) {
-		return err
-	}
-	if pdb != nil && pdb.Name != "" {
-		woc.log.Info("PDB resource already exists for workflow.")
-		return nil
-	}
-
+	labels := map[string]string{common.LabelKeyWorkflow: woc.wf.Name}
 	pdbSpec := *woc.execWf.Spec.PodDisruptionBudget
 	if pdbSpec.Selector == nil {
 		pdbSpec.Selector = &metav1.LabelSelector{
-			MatchLabels: map[string]string{common.LabelKeyWorkflow: woc.wf.Name},
+			MatchLabels: labels,
 		}
 	}
 
 	newPDB := policyv1.PodDisruptionBudget{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:   woc.wf.Name,
-			Labels: map[string]string{common.LabelKeyWorkflow: woc.wf.Name},
+			Labels: labels,
 			OwnerReferences: []metav1.OwnerReference{
 				*metav1.NewControllerRef(woc.wf, wfv1.SchemeGroupVersion.WithKind(workflow.WorkflowKind)),
 			},
 		},
 		Spec: pdbSpec,
 	}
-	_, err = woc.controller.kubeclientset.PolicyV1().PodDisruptionBudgets(woc.wf.Namespace).Create(ctx, &newPDB, metav1.CreateOptions{})
+	_, err := woc.controller.kubeclientset.PolicyV1().PodDisruptionBudgets(woc.wf.Namespace).Create(ctx, &newPDB, metav1.CreateOptions{})
 	if err != nil {
+		if apierr.IsAlreadyExists(err) {
+			woc.log.Info("PDB resource already exists for workflow.")
+			return nil
+		}
 		return err
 	}
 	woc.log.Info("Created PDB resource for workflow.")