Add a slow e2e test to monitor kubelet resource usage

This test tracks kubelet resource usage over a long period of time (1hr)
when running N pods (e.g., N=0,50), and prints out the resource usage. This
would give us an idea how much kubelet's management overhead is in a stable
cluster.

Some followup items:
 * Use a more realistic workload (e.g., including probing)
 * Fail the test if the resource usage is too high.

Caveat:
 * We assume the scheduler would do a decent job distributing the pause pods,
   but we should double check.
 * Cluster addon pods could be unevenly distributed and skews the resource
   usage on nodes.

test/e2e/kubelet.go

@@ -37,7 +37,6 @@ const (
 	pollInterval = 1 * time.Second
 	// Interval to poll /stats/container on a node
 	containerStatsPollingInterval = 5 * time.Second
-	resourceCollectionTime        = 1 * time.Minute
 )
 
 // getPodMatches returns a set of pod names on the given node that matches the
@@ -160,16 +159,4 @@ var _ = Describe("kubelet", func() {
 			})
 		}
 	})
-
-	Describe("Monitor resource usage on node", func() {
-		It("Ask kubelet to report container resource usage", func() {
-			// TODO: After gathering some numbers, we should set a resource
-			// limit for each container and fail the test if the usage exceeds
-			// the preset limit.
-			By(fmt.Sprintf("Waiting %v to collect resource usage on node", resourceCollectionTime))
-			time.Sleep(resourceCollectionTime)
-			resourceMonitor.LogLatest()
-			resourceMonitor.LogCPUSummary()
-		})
-	})
 })