improve retry logic with standard wait.Poll()

Signed-off-by: He Simei <hesimei@zju.edu.cn>

test/e2e/reboot.go

@@ -24,6 +24,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/wait"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -255,11 +256,11 @@ func waitForNodeToBeNotReady(c *client.Client, name string, timeout time.Duratio
 // ready or unknown).
 func waitForNodeToBe(c *client.Client, name string, wantReady bool, timeout time.Duration) bool {
 	Logf("Waiting up to %v for node %s readiness to be %t", timeout, name, wantReady)
-	for start := time.Now(); time.Since(start) < timeout; time.Sleep(poll) {
+	expectNoError(wait.Poll(poll, timeout, func() (bool, error) {
 		node, err := c.Nodes().Get(name)
 		if err != nil {
 			Logf("Couldn't get node %s", name)
-			continue
+			return false, nil
 		}
 
 		// Check the node readiness condition (logging all).
@@ -270,10 +271,11 @@ func waitForNodeToBe(c *client.Client, name string, wantReady bool, timeout time
 			// matches as desired.
 			if cond.Type == api.NodeReady && (cond.Status == api.ConditionTrue) == wantReady {
 				Logf("Successfully found node %s readiness to be %t", name, wantReady)
-				return true
+				return true, nil
 			}
+
 		}
-	}
-	Logf("Node %s didn't reach desired readiness (%t) within %v", name, wantReady, timeout)
-	return false
+		return false, nil
+	}))
+	return true
 }