Restructures SSH trust relationships from global to host-specific configuration
for better locality of concern and principle of least privilege.
Changes:
- Collapse nixos/common/global/ssh/ back to ssh.nix (single-file module)
- Move internal host trust (fuchsia/viridian) to per-host services/ssh/
- Split BorgBase known hosts by repository (li9kg944 for fuchsia, r7ag7x1w for viridian)
- Add viridian SSH server config to accept backup connections from fuchsia
- Add fuchsia borgbackup passphrase for offsite backups
- Configure viridian to create /srv/borg-repo/fuchsia for remote backups
This enables the 3-2-1 backup strategy with fuchsia backing up to both viridian
(onsite) and BorgBase (offsite) with proper SSH authentication.
Add automated snapshot and backup system with three independent tiers:
Snapper (hourly local snapshots):
- Configure snapper for all srv-* subvolumes
- Tiered retention: 24 hourly, 7 daily, 4 weekly, 12 monthly
- Snapshots stored at /.snapshots on viridian drive
- Provides fast operational rollback for user errors
Borgbackup onsite (hourly local backups):
- Independent staging snapshots at /.staging-onsite
- Repository on data drive at /srv/borg-repo
- Unencrypted (physical security assumed)
- Matches snapper retention policy
- Fast local disaster recovery
Borgbackup offsite (daily remote backups):
- Independent staging snapshots at /.staging-offsite
- Encrypted backups to borgbase repository
- Retention: 7 daily, 4 weekly, 12 monthly
- Remote disaster recovery with prune policy
Architecture decisions:
- Separate staging directories prevent job conflicts
- Staging snapshots decouple borg jobs from snapper
- Consistent zstd,9 compression across both borg jobs
- Special case handling for containers subvolume path
Migrate from path-based persistence (/persist/var/lib/*) to dedicated
BTRFS subvolumes for better data isolation and snapshot capabilities.
- Move valuable user-facing services to /srv/* with srv-* subvolumes:
- forgejo: git repositories and database
- opengist: paste data
- minecraft: game world data
- lighttpd: static web content
- containers: OCI container volumes
- Update home directory to use hm-sajenim subvolume on viridian disk
- Remove jupyterhub service (no longer in use)
- Update borgbackup paths to match new service locations
- Follow upstream service defaults where possible for maintainability
Services kept on /persist (disposable state):
- traefik, crowdsec, murmur
