Automatic merge from submit-queue
Implement 'kubectl top' command
```release-note
Added 'kubectl top' command showing the resource usage metrics.
```
Sample output:
Nodes:
```
$ kubectl top node
NAME CPU MEMORY STORAGE TIMESTAMP
kubernetes-minion-group-xxxx 76m 1468 Mi 0 Mi Tue, 12 Jul 2016 17:37:00 +0200
kubernetes-minion-group-yyyy 73m 1511 Mi 0 Mi Tue, 12 Jul 2016 17:37:00 +0200
kubernetes-minion-group-zzzz 46m 1506 Mi 0 Mi Tue, 12 Jul 2016 17:37:00 +0200
kubernetes-master 76m 2059 Mi 0 Mi Tue, 12 Jul 2016 17:37:00 +0200
```
Pods in all namespaces:
```
$ kubectl top pod --all-namespaces
NAMESPACE NAME CPU MEMORY STORAGE TIMESTAMP
default nginx-1111111111-zzzzz 0m 1 Mi 0 Mi Tue, 12 Jul 2016 17:49:00 +0200
kube-system etcd-server-kubernetes-master 4m 116 Mi 0 Mi Tue, 12 Jul 2016 17:49:00 +0200
kube-system fluentd-cloud-logging-kubernetes-minion-group-xxxx 14m 110 Mi 0 Mi Tue, 12 Jul 2016 17:49:00 +0200
kube-system kube-dns-v18-zzzzz 1m 6 Mi 0 Mi Tue, 12 Jul 2016 17:49:00 +0200
...
```
Pod with containers:
```
$ kubectl top pod heapster-v1.1.0-1111111111-miail --namespace=kube-system --containers
NAMESPACE NAME CPU MEMORY STORAGE TIMESTAMP
kube-system heapster-v1.1.0-1111111111-miail 1m 42 Mi 0 Mi Tue, 12 Jul 2016 17:52:00 +0200
heapster 1m 26 Mi 0 Mi
eventer 0m 3 Mi 0 Mi
heapster-nanny 0m 6 Mi 0 Mi
eventer-nanny 0m 6 Mi 0 Mi
```
ref #11382
[]()
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.kubernetes.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.kubernetes.io/reviews/kubernetes/kubernetes/28844)
<!-- Reviewable:end -->
PLEASE NOTE: This document applies to the HEAD of the source tree
If you are using a released version of Kubernetes, you should refer to the docs that go with that version.
The latest release of this document can be found [here](http://releases.k8s.io/release-1.3/docs/README.md).Documentation for other releases can be found at releases.k8s.io.
Kubernetes Documentation: releases.k8s.io/HEAD
-
The User's guide is for anyone who wants to run programs and services on an existing Kubernetes cluster.
-
The Cluster Admin's guide is for anyone setting up a Kubernetes cluster or administering it.
-
The Developer guide is for anyone wanting to write programs that access the Kubernetes API, write plugins or extensions, or modify the core code of Kubernetes.
-
The Kubectl Command Line Interface is a detailed reference on the
kubectlCLI. -
The API object documentation is a detailed description of all fields found in core API objects.
-
An overview of the Design of Kubernetes
-
There are example files and walkthroughs in the examples folder.
-
If something went wrong, see the troubleshooting document for how to debug. You should also check the known issues for the release you're using.
-
To report a security issue, see Reporting a Security Issue.