The previous revision skipped `usermod -aG incus` for an incus-admin member,
reasoning that 'incus' is a strict subset of what incus-admin already opens.
That is true of the daemon API and false of the filesystem. On Debian 13 /
Incus 6.0.4 the two sockets are two files with two owning groups:
/var/lib/incus/unix.socket group incus-admin 0660
/var/lib/incus/unix.socket.user group incus 0660
incus-admin opens the first and not the second, and only the second
provisions a user-<uid> project. So for the incus-admin-ONLY user — the
canonical #99 case — the pinned provisioning touch took EACCES, the `|| true`
swallowed it, no project appeared, and the grant died blaming a healthy
incus-user. Both reviewers converged on this independently and were right.
The membership is now granted for everyone, with output carrying the concern
the old no-op was built around (it is the key to a file, not a privilege;
box_tier still reads them as admin). Everything downstream moves with it:
- the backout rolls that membership back and verified, while refusing to call
the rollback a lockout — incus-admin is untouched and still opens the host
- revoke's bare path takes the membership back and reports `partial:` instead
of "no-op, nothing was taken", still declining to call them "out"
- grant's closing "gpasswd -d <user> incus-admin (no re-grant needed)" is now
a true promise: they keep 'incus', so the drop lands them in their project
- the socket existence probe goes through $SUDO, matching revoke's measured
discipline about /var/lib/incus lying to a non-root admin
Tests: the cli.sh assertions that encoded the old no-op design are flipped and
the decision is pinned at the seam that broke; the sudo shim now runs `test`
for real in both directions. Because the shims model neither INCUS_SOCKET nor
permissions and so cannot reproduce the EACCES, drill/multiuser.sh gains
criterion (o): an incus-admin-only member granted on real Incus in CI, with
the membership, the project, a live connect() to unix.socket.user, and the
post-drop landing all measured.
Mutation-checked: 11 of the new/flipped assertions fail against the previous
implementation.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Run inside a box, setup-host built a nested boxnet claiming the exact
subnet and gateway of the guest's own uplink: the guest then held
10.88.0.1 as a LOCAL address while its default route pointed at 10.88.0.1
as its GATEWAY, carried two connected routes for the subnet, and suffered
intermittent, self-recovering egress blackouts (~24-36 s, roughly hourly)
that no host-side check could attribute. The flagship use case funnels
agents toward exactly this — working on box, in a box — so the guard, not
the operator, has to catch it.
setup-host now scans the target subnet BEFORE any mutation: the default
route's gateway inside it (the smoking gun — that is this machine's own
uplink), or any non-boxnet interface holding an address in it, refuses
with the way out named (BOX_SUBNET). A prior boxnet owning the subnet is
the one claimant that is NOT a collision — the legitimate re-run — and an
existing bridge on a DIFFERENT subnet refuses too: setup-host converges a
bridge, it never re-addresses one under live leases.
BOX_SUBNET=<a.b.c.0/24> (validated at the gate, alongside BOX_DNS) moves
the whole stack from one place:
· the bridge address derives (ipv4.address=<gw>/24)
· the ACL's gateway carve-out derives — and the ruleset is now converged
via 'network acl edit', not created once: the #80 escape hatch (moving
the bridge) left the old /32 behind, stranding box DNS inside the
10.0.0.0/8 drop, which presents as a dead resolver, never as a stale
ACL
· box-firewall reads the gateway off the live bridge ('|| true' because
under pipefail an absent bridge would kill the script instead of
answering "no bridge yet")
· the drill, multiuser rehearsal and migrate-host probes derive the
prefix from 'incus network get boxnet ipv4.address' instead of
hardcoding 10.88 — a BOX_SUBNET host must not fail its own rehearsals
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Three of the four round-1 nits, taken: --force's overwrite role on
export now sits in OPTIONS and 'help export' (it was only in the die
text); the restricted-tier rehearsal asserts restricted.backups=allow
beside the snapshots check it mirrors, so the grant key #70 depends on
is proven live, not only grepped; and reset_identity says "instance" —
it has two callers now, and only one of them clones. The install.sh
message stays #79's (the documented merge order).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
incus 6.0.4 lets a restricted cert reference an allowed network with a raw
--network flag; 6.0.0 (ubuntu-latest) refuses it at the permission layer.
The first is the world criterion (m)'s measurements exist for; the second
is PREVENTION — the strongest of the review's three resolutions — and the
probe now recognizes it as such (with the refusal quoted) instead of dying
unmeasured. The (n) blocker is now staged with 'incus config device
override' — their own instance, their own stock profile NIC lifted
instance-local, permitted on both versions, and the exact shape that
actually blocks narrowing. Both staging failures now print their reasons;
swallowed narration is how this file's false FAILs happened.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Review 4727756972 (A2): the backout no longer trusts gpasswd — it re-reads
the live group database after removal; verified-absent gets the safe
message, anything else screams ROLLBACK INCOMPLETE, exits nonzero, and
names the exact remediation. The concurrent-login window (a session begun
between usermod and backout keeps the group) is CLOSED to the extent the
database can't reach: the backout detects live processes and names
loginctl terminate-user, and the success wording claims only what was
verified.
Review 4727641752 (A1): a failed grant for a user whose membership predates
the run (the hand-added-user scenario) now fails LOUDLY — they retain
socket access on part-converged policy, and the message says so with both
remediations (box revoke now, or fix and re-run). Their membership is not
stripped: breaking a working user over a failed re-grant is its own hazard.
The default-profile eth0 removal is deliberately not restored on failure —
that mutation only reduces capability, and restoring it would move the
failure state AWAY from fail-closed. Injected-failure coverage is criterion
(n), both flavors: fresh-user backout (fault at the LAST mutation, so the
rollback runs after every earlier one) with the group's absence verified
and a converging re-run; blocked narrowing staged for real with an
instance-local NIC parked on the private bridge.
Review A3, resolution 3 with the measurement demanded: criterion (m)
launches exactly 'incus launch --network boxnet' as the restricted user and
probes the raw NIC from inside — egress works, RFC1918 dropped (the ACL is
the network's), sibling probes dropped BOTH directions (the nft drop is the
host's), name enumeration blocked. The scoped guarantee is now stated in
box-design.md and measured on every run: box-minted instances carry per-NIC
port_isolation; raw attachments keep every network- and host-owned control,
losing only that redundant L2 layer. Instrument lesson kept as MU-5: the
probe's first cut minted the non-cloud image — no DHCP client, no lease,
and a dead NIC passes every negative probe vacuously; it now requires the
lease before believing its own answers.
Rehearsal: 54/54 (containers). test/cli.sh: 82 checks.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
incus 6.0.4 refuses the private-bridge attach before 'Launching', 6.0.0
(ubuntu-latest) after it — with different words. Chasing message strings
across releases is a losing game: the probe now demands the fact (rc!=0 AND
nothing running on the bridge) and prints the refusal line as evidence in
every run log. First caught by the CI rehearsal doing exactly the job it
was added for.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Supplementary groups are read at LOGIN, so 'gpasswd -d' does nothing to a
session the user already holds — and after --purge, a stale-group process
could touch incus-user and lazily RECREATE the project with stock defaults:
the unhardened NAT bridge, un-narrowed, strictly worse than the granted
state. Adversarial review caught it; verified live, then closed:
- revoke --purge terminates the user's sessions first (loginctl, then
pkill), and refuses to purge under processes it cannot kill
- bare revoke says out loud that held sessions keep the socket until they
end, and names the loginctl command — instead of claiming a lockout it
did not deliver (help/README/design doc reworded to match)
- a failed grant backs out its own group-add on exit (trap, disarmed on
success): no half-granted user holding an un-narrowed socket while the
admin reads the error. Verified by injecting a bad profile YAML
- the rehearsal now holds a session open across the purge and demands it
dies with the tier (criterion l, 42nd check)
Smaller review findings, same pass: the escape-hatch probes assert the
refusal's REASON instead of any nonzero exit (an image hiccup must not read
as 'the escape is closed'); probe_from maps an outer-timeout kill to
dropped, not reachable; the rehearsal cleanup keeps the account when a purge
fails so doctor can name the leftovers; the purge asserts the trust
certificate's absence; cmd_new distinguishes a dead daemon from a missing
stack before prescribing setup-host; grant's success message names the
user-<uid> bridge variant correctly on big-uid hosts.
Rehearsal after: 42/42 (containers). test/cli.sh: 76 checks.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
drill/multiuser.sh: two throwaway users, real grants, real boxes, and the
contract measured from INSIDE them — #74's criteria (a)-(f) plus what the
findings added: the cross-user sibling drop, the closed private-bridge
escape hatches, incus-user re-sync survival, scoped revoke --purge. Its own
first runs are in RUNS.md (MU-1..3): both false FAILs were the instrument,
and both lessons (keep the mint's narration; probe a SIBLING's name, never
your own — /etc/hosts answers for you) are now comments in the script.
test/cli.sh: box_tier() driven against a shim id for all five cases
(including both-groups → admin: membership wins at the socket), the two
copies diffed byte-identical, the tier scripts' usage contracts driven for
real, and grep-guards on every load-bearing line a daemon-free run cannot
exercise — the expose guard's position, the boxnet-and-only-boxnet
narrowing, the snapshot allow, 'incus:snapshot restore'.
ci.yml: a second job stands up the real stack on the runner (setup-host,
doctor, then the rehearsal in container mode) — every PR now proves the
tier's semantics against a live daemon. The tier's mechanics are
instance-type-independent (the drop, the ACL, dns.mode and port_isolation
bind to boxnet, not the instance); the VM trust boundary itself stays a
real-hardware ritual, like the full drill.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
