Great article for quick and dirty setup of haproxy on CentOS 7 (RHEL 7)
https://www.server-world.info/en/note?os=CentOS_7&p=haproxy
And a similar article for LVS (iplvadm)
https://www.server-world.info/en/note?os=CentOS_7&p=lvs
To cement the iplvadm config:
# This worked the first time, but not the second. Needed to use zone ‘internal’
firewall-cmd –zone=private –add-interface=ens9
# add the line NM_CONTROLLED=no
vi /etc/sysconfig/network-scripts/ifcfg-Wired_connection_1
service network restart
# then… And make it permanent
firewall-cmd –zone=public –add-masquerade
firewall-cmd –permanent –zone=public –add-masquerade
firewall-cmd –permanent –zone=internal –add-interface=ens9
I found this to be helpful in setting up keepalived
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Load_Balancer_Administration/ch-initial-setup-VSA.html
