Duplicate Undercloud Host entry During Stack Update

Issue

• We have one DCN multi stack and whenever we are adding/updating the stack then the duplicate entry of undercloud ctlplane is appending in the /etc/hosts file on undercloud node.

• Here is an example of the /etc/hosts file:

172.16.52.xx auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.localdomain auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01 auh-xxxxx-xxx-vran-cmn-xxx-ddirt01.ctlplane