[Samba] Floating IP breaks AD replication

[Sven Wick]

> we point them to somedom.contoso.com which is then
> resolved to both and the client can pick

I want to avoid Round-Robin DNS

> You cannot use CTDB with AD DCs

You can.


/etc/ctdb/nodes

192.168.30.11
192.168.30.12

/etc/ctdb/public_addresses

192.168.30.10/24 ens18

/etc/ctdb/events/legacy/20.samba-ad.script

#!/usr/bin/env bash
 
function monitor_ldap() {
  
  ldbsearch -H ldap://127.0.0.1 -s base -b "" vendorName 2>/dev/null | grep -qi samba 

  if [[ $? -eq 0 ]]; then
    return 0
  else
    echo "ldbsearch received no info"
    return 1
  fi
}
 
case "$1" in
 
monitor)
    monitor_ldap || exit 1
    ;;
esac
 
exit 0



I used to use keepalived for this kind of setups
but ctdb is a neat solution so I switched.

When I change

/etc/ctdb/public_addresses

from 192.168.30.10/24 ens18
to   192.168.60.10/24 ens18

the replication does not break
because x.x.60.0 is not the internal DNS Zone

This setup allows me to upgrade, reboot
each DC without downtime because
ctdb checks for samba and moves the floating IP.