change to multistream concheck

[sunya-ch]

This PR changes server and client command generation from single stream to multiple stream for full bandwidth measurement.

Example:

generated server command

  containers:
  - args:
    - ' (for i in {1..5}; do iperf3 -s -p 501$i & done) &  (for i in {1..5}; do iperf3
      -s -p 502$i & done) & (tail -f /dev/null)'
    command:
    - /bin/sh
    - -c

generated client command

  containers:
  - args:
    - ' (for i in {1..5}; do iperf3 -Z -t 10s -c 192.168.0.1 -p 501$i --connect-timeout
      10s & done  | grep ''receiver'' | awk ''{s+=$7} END{print "192.168.0.1,"s$8}'')
      & (for i in {1..5}; do iperf3 -Z -t 10s -c 192.168.64.1 -p 502$i --connect-timeout
      10s & done  | grep ''receiver'' | awk ''{s+=$7} END{print "192.168.64.1,"s$8}'')
      &wait; sleep 1;echo ''''; (for i in {1..5}; do iperf3 -Z -t 10s -c 192.168.0.65
      -p 501$i --connect-timeout 10s & done  | grep ''receiver'' | awk ''{s+=$7} END{print
      "192.168.0.65,"s$8}'') & (for i in {1..5}; do iperf3 -Z -t 10s -c 192.168.64.65
      -p 502$i --connect-timeout 10s & done  | grep ''receiver'' | awk ''{s+=$7} END{print
      "192.168.64.65,"s$8}'') &wait; sleep 1;echo '''';'
    command:
    - /bin/sh
    - -c

Signed-off-by: Sunyanan Choochotkaew sunyanan.choochotkaew1@ibm.com