I build myself a fedora coreos based nextcloud instance with encrypted backup to S3: https://github.com/jeppester/coreos-nextcloud

In short you fill in the env-files, then run butane and ignition. (I should improve the README some time)

I love how it's all configuration. If it breaks I can set up another instance with the same secrets in minutes. It will then grab the latest backup and continue like nothing happened.