Comment 8 for bug 1839300

A related issue for Octavia was handled before the 19.10 release in bug 1845303, there we chose to have Octavia configured based on whichever hostname charm-neutron-openvswitch chose [0][1][2].

In retrospect it should probably be the other way around, i.e. the principle charm deciding which FQDN the subordinate uses.

I do understand your wish for "just using the primary FQDN" of a host, but from the charms perspective there is unfortunately no such thing. There is no system call that accurately provides that information, the charm has to actively select a interface and IP address to build the FQDN from.

0: https://review.opendev.org/#/c/685940/
1: https://review.opendev.org/#/c/685941/
2: https://review.opendev.org/#/c/685942/