[kolla] restart mariadb container on host 1

Hi all,

I wanted to temporarily change a mariadb config in /etc/kolla/mariadb/galera.cnf so I intended to stop mariadb on host 1, make the change, start it again, then repeat in turn for hosts 2 and 3.

Upon starting it on host 1, it doesn't rejoin, but creates its own separate cluster. Dutiful really, since logs show:

WSREP: 'wsrep-new-cluster' option used, bootstrapping the cluster

How do I avoid that? General advice on handling this kind of activity would also be welcome.

Thank you, Greg.