Need docker mount/backup strategy

Of relation to daily backups that cover not just data but configurations per container as well, what sort of strategies are there in structuring containers/volumes? For data volume mounts, that’s quite simple. In the case of nginx/php where each “vhost” may require different configuration. for example: rewrite rules in nginx.conf, or special php modules that need to be installed, or otherwise different SSL configurations involving different certs. I would classify them as “unique” configuration per I was advised against doing volume mounts for /etc/{nginx,php} and that i should backup the entire image?! here’s where im confused. Do i make an image PER ‘virtualhost/’? this doesn’t seem the most ideal either. what if configuration changes often?

I want to be able to recover wholistically should tragedy arise.

What options are there?