[validate] should run iperf2

[yzaccc]

1. set up iperf2 server -- a single pod on any node
2. set up iperf2 client daemonset
3. wait for server running
4. wait for all clients running
5. iterate through the client pods one by one, running iperf2 in client mode to transfer data to the server and back and measure bandwidth
6. after collecting all the client<->server data, compile and present the results

note: /* iperf2 command parameters:

• -e: use enhanced reporting giving more tcp/udp and traffic information
• -p %d: server port to connect to
• --reportstyle C: report as Comma-Separated Values
• -i 1: seconds between periodic bandwidth reports
• -c %s: run in client mode, connecting to */

[yzaccc]

as using iperf consumes a lots of time, cannot do all the tests using iperf, currently we should limit to do one test using it, to test ClusterIP connectivity.

[yzaccc]

Currently the perf testing set up a server on all the nodes, and run in another name space. Need to add a test for perf testing use the currently namespace, and only one iperf server is needed(on any node.)