## Context
Upstream Wealthfolio uses SQLite exclusively (Diesel ORM, no PG/MySQL
support — confirmed 2026-04-18 via repo inspection). The DB lives on
an RWO PVC (proxmox-lvm-encrypted) held 24/7 by the main pod.
First attempt at a standalone backup CronJob failed with Multi-Attach
error: RWO volume is already attached to the running WF pod, so no
separate pod can mount it. Switched to a backup sidecar in the same
pod — shares the PVC mount naturally.
## This change
- `container "backup"` added to the WF Deployment:
- alpine:3.20 + sqlite + busybox-suid (for crond).
- Mounts /data read-only (shared with WF container) + /backup (new
NFS volume at 192.168.1.127:/srv/nfs/wealthfolio-backup).
- Writes /etc/crontabs/root with a `30 4 * * *` line + /scripts/backup.sh
which runs `sqlite3 .backup` (WAL-safe online snapshot, zero
downtime), copies secrets.json, and prunes anything older than 30d.
- 16Mi request / 64Mi limit — sleeps most of the time.
- NFS volume declared in pod spec — server from the existing
`var.nfs_server` variable; path `/srv/nfs/wealthfolio-backup` created
on the PVE host in the same session.
Removed the standalone backup CronJob that couldn't work.
## Verification
### Automated
`scripts/tg apply stacks/wealthfolio` → Apply complete! Resources: 0
added, 1 changed, 1 destroyed (the transient CronJob).
### Manual (2026-04-18)
$ kubectl -n wealthfolio get pods -l app=wealthfolio
wealthfolio-95d8bd498-cj8kw 2/2 Running
$ kubectl -n wealthfolio logs <pod> -c backup
wealthfolio-backup sidecar ready; next 04:30 UTC
$ kubectl -n wealthfolio exec <pod> -c backup -- /scripts/backup.sh
wealthfolio-backup: /backup/2026-04-18T22-24-55 (34.2M)
$ ls /srv/nfs/wealthfolio-backup/
2026-04-18T22-24-55/ ← first sidecar-produced backup
## Reproduce locally
1. kubectl -n wealthfolio exec $(kubectl -n wealthfolio get pods -l app=wealthfolio -o jsonpath='{.items[0].metadata.name}') -c backup -- /scripts/backup.sh
2. ssh root@192.168.1.127 ls /srv/nfs/wealthfolio-backup/
3. Expected: new dated folder appears with wealthfolio.db + secrets.json.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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