I was reading the documentation page on deploying CoreOS to DigitalOcean and I during the process I was looking to add/attach a DO block/volume to the droplet. This lead me down the path of trying to find a reference to the file structure for CoreOS. I’m pretty safe to assume that /var is something that should be backed/retained for system updates/failures.
Specifically I’m thinking of something like running a container with something like Caddy server that handles certificates with Let’s Encrypt. Those certificates should/would be nice to have as a backup/shared volume between system updates.
Is there a reference page (I could not find one) that discusses the file system structure and the use cases? I vaguely remember the original CoreOS having something similar…