Role `box` resolved to exactly one action, `usermod -aG incus`. That is
the socket — step 1 of the five `box grant` performs. Without the other
four (the user-<uid> project, its narrowing to boxnet and only boxnet,
the snapshot and backup allowances clone and `box export` ride, and the
shipped box-net profile installed into that project) the user's first
`box new` refuses for want of a box-net profile, so apply's promise —
the users file is the fleet's source of truth — was not kept for this
role. Worse, until an admin arrived by hand the user held an `incus`
membership with no converged project, and incus-user would lazily hand
them a stock unhardened NAT bridge: a state box's own contract forbids.
On host=yes apply now calls `box grant <user>` per box-role user. rig
calls box's grant rather than reimplementing four fifths of it — the
"rig never installs Incus" boundary is about installation, not
invocation, and grant is already script-callable: idempotent,
root-or-sudo, stdin-pinned, with its own run-as-the-user touch.
Three decisions the code carries in comment form:
- Ordering. The call sits after `useradd` (grant opens with a getent
passwd and refuses an unknown account) and after the other groups, so
a user whose grant fails still lands with everything rig owns outright.
- Failure granularity, split the way the host= guard beside it already
splits. A missing box CLI on host=yes dies, like the missing incus
group: a broken VM host, not a per-user accident. A per-user grant
failure warns and continues — one box-role user somewhere in the fleet
must not stop apply everywhere VMs don't live. host=no and marker-less
boxes keep their existing skip-with-warning untouched.
- The group ADD is deferred to grant, while `incus` stays in the wanted
set so the exact-convergence loop never strips a box-role user's
socket. Grant's rollback only reaches a membership that run added, so
rig opening the socket first would leave a failed grant unable to
close it. And grant is the authority on whether the group belongs at
all: for an incus-admin member it deliberately does not add `incus`.
An incus-admin member is warned, never fatal: box grant refuses them
today, which heavy-duty/box#99 fixes box-side with no rig change needed.
Closes#49
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
a950569832