Use IP Range or CIDR for K6 source IP addresses

[divfor]

An alternative PR for using IP range option #1293 , no Network Interface required.
Example of run script:

#!/bin/bash
s=${1:-"ax.js:1000:10m:rps_http"}
read jsfile vus duration casename <<<${s//:/ }
shift
echo -e "testfile[$jsfile] testcase[$casename] vus[$vus] duration[$duration]\noptions[$*]"

set_k6_local_route(){ #$1:net $2:ifname
  net="$1" ifname=${2-"lo"}
  ip r s t local |grep -q "^local $net" || \
  ip -6 r s t local |grep -q "^local $net" || \
  ip route add local "$net" dev $ifname
  ip r s t local |grep "^local $net" || ip -6 r s t local |grep "^local $net"
}

# k6 client ip -- use local type route instead
set_k6_local_route "10.50.0.0/16" "eth0"
set_k6_local_route "fd00:0:1::0/120" "eth0"

# Linux: echo "ulimit -n 1000000" >> ~/.bashrc
# MacOS: sudo launchctl limit maxfiles 65536 1000000
ulimit -n 1000000

# run k6 for ipv4 targets
TESTCASE=$casename VUS=$vus DURATION=$duration k6 run --ip="10.50.0.62-10.50.2.100" --verbose --no-thresholds $* $jsfile
# run k6 for ipv6 targets
sysctl -w net.ipv6.ip_nonlocal_bind=1
TESTCASE=$casename VUS=$vus DURATION=$duration k6 run --ip="fd00:0:188::/120" --verbose --no-thresholds $* $jsfile
sysctl -w net.ipv6.ip_nonlocal_bind=0

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ divfor
❌ Fred Huang

---

Fred Huang seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[na--]

Hey, @divfor, can we help in some way? If the issue is caused by a wrong commit author, maybe this will help - https://www.git-tower.com/learn/git/faq/change-author-name-email/