VyOS already has rollback, but `rollback 1` returns you to the *previous*
revision, which may itself be broken — you can end up walking backwards through
several bad commits hunting for the one that worked, at exactly the moment you
have no network to look things up with. This pins a state a human has actually
used and found working, so recovery is one step and needs no memory of how many
changes ago things were fine.
/config/vyos-known-good save pin the running config
/config/vyos-known-good status when it was taken, how running differs
/config/vyos-known-good diff what a restore would change
/config/vyos-known-good restore go back to it
Deliberately not automatic. A config is only known-good once someone has used
the network; a snapshot taken after every commit would faithfully preserve the
broken one.
The restore is itself commit-confirmed, so even the recovery path is protected:
if the snapshot is somehow wrong, or access is still broken and nothing can be
confirmed, the router undoes the restore rather than leaving you worse off.
Silence reverts.
`save` refuses when there are uncommitted changes — a snapshot that did not
match what is actually running would look like a safety net without being one.
Two things found while building it, both of which made the script silently
useless rather than fail loudly:
- Sourcing `script-template` **resets the positional parameters**, so `$1` was
empty by the time the case statement ran and every invocation fell through
to the usage message. Arguments are captured before the source.
- `0600` made the snapshot unreadable to the `vyos` user, so `status` and
`diff` — the two commands you run while deciding whether to restore — showed
nothing. Now 0660 root:vyattacfg, matching /config/config.boot.
Installed on both routers with the current, verified-working config pinned
(vyos001 1029 lines, vyos002 1019).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
