reuse polling function

pkg/oc/admin/diagnostics/diagnostics/cluster/app_create/setup_cleanup.go

@@ -6,12 +6,15 @@ import (
 	"time"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
 
 	appscmd "github.com/openshift/origin/pkg/apps/cmd"
 	"github.com/openshift/origin/pkg/cmd/server/bootstrappolicy"
 	newproject "github.com/openshift/origin/pkg/oc/admin/project"
 )
 
+const podGoneTimeout = 30 // seconds to wait for previous app pods to disappear
+
 func (d *AppCreate) prepareForApp() bool {
 	defer func() {
 		d.result.PrepDuration = jsonDuration(time.Since(time.Time(d.result.BeginTime)))
@@ -101,17 +104,20 @@ func (d *AppCreate) cleanupApp() {
 
 func (d *AppCreate) waitForPodGone() bool {
 	d.out.Debug("DCluAC045", fmt.Sprintf("%s: Waiting to ensure any previous pod for '%s' is gone.", now(), d.appName))
-	for timeout := 30; timeout > 0; timeout-- {
+	err := wait.PollImmediate(time.Second, time.Duration(podGoneTimeout)*time.Second, func() (bool, error) {
 		pods, err := d.KubeClient.Core().Pods(d.project).List(metav1.ListOptions{LabelSelector: d.labelSelector})
-		if err != nil {
-			d.out.Error("DCluAC046", err, fmt.Sprintf("%s: Error on checking for previous app pod:\n%v", now(), err))
-			return false
-		}
-		if len(pods.Items) == 0 {
-			return true
+		if err == nil && len(pods.Items) == 0 {
+			return true, nil
 		}
-		time.Sleep(time.Second)
+		return false, err
+	})
+	switch err {
+	case nil:
+		return true
+	case wait.ErrWaitTimeout:
+		d.out.Error("DCluAC046", err, fmt.Sprintf("%s: Previous app pod still present after %ds", now(), podGoneTimeout))
+	default:
+		d.out.Error("DCluAC047", err, fmt.Sprintf("%s: Error while checking for previous app pod:\n%v", now(), err))
 	}
-	d.out.Error("DCluAC047", nil, fmt.Sprintf("%s: Previous app pod still present after 30s", now()))
 	return false
 }