Run 7's box had no network — a clone/source IP collision had taken it down before a single hardening change was applied. Phase D measured anyway and reported "L2 filtering BREAKS the box — design veto". It does not. The box was already broken, and #16 would have been redesigned around a fiction. Phase D is now gated on baseline egress passing, and says loudly that it is skipping rather than quietly producing a verdict. The dns.mode rejection also stops swallowing incus's error message — the message IS the finding. RUNS.md gains trap 9: check that the thing you are measuring WITH still works before you trust what it tells you. Same failure as the B3 flip, different costume. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
9.2 KiB
Drill run log
What the drill has actually found, what has broken in the drill itself, and how to diagnose the next stall without starting from zero. Append a section per run; keep the traps table current — it is the part that saves time.
The audit this feeds is #15.
Where the audit stands
| Probe | Answer | Run |
|---|---|---|
| A1/A5 egress + gateway DNS | PASS | 2, 3, 4 |
| A2 box → host | dropped | 2, 3, 4 |
| A2 box → RFC1918 | dropped | 2, 3, 4 |
| A3 sibling isolation | ⏳ still unanswered — blocked by a drill bug in every run so far | — |
| A4 DNS enumeration | LEAKS — a box resolves its sibling by name (as #12 predicted) | 2, 3, 4 |
| A6 IPv6 off | none ✓ |
2, 3, 4 |
| A7 inbound host → box | dropped | 3, 4 |
B1 @internal on a bridge ACL |
REJECTED — Unsupported nftables subject ⇒ #16 derives the subnet |
2, 3 |
B2 incus copy preserves user.* |
YES ⇒ #17's metadata design holds | 2, 3, 4 |
B3 dns.mode=none |
closes the leak; egress verdict FLIPPED between runs (see below) | 2, 3 |
B4 config get on unset key |
empty + exit 0 ⇒ #17 must use ${var:-}, never || |
2, 3, 4 |
| B5 L2 filtering | box networking intact; in-box docker unverified | 2, 3 |
A3 is the whole point and it has never fired. It is the one claim #12 could not verify from a code reading. Until it is answered, #16 does not know whether it is writing a formalization or a fix.
Findings in claudebox (not in the drill)
| Finding | Status |
|---|---|
setup-host.sh called nft but a stock Debian 13 cloud image ships neither nftables nor UFW — host setup died on a fresh cloud host |
fixed (setup-host installs it) |
claudebox exec box -- claude … — the help's own example — failed: the binary is in ~/.local/bin, but cloud-init exported PATH only in .bashrc/.zshrc, which the non-interactive shell behind exec never reads (login shell is zsh, so even sudo -i misses both) |
fixed (symlink into /usr/local/bin) |
Cold mint takes ~95s, not the ~10 min the docs claim — consistently. Either the host is fast, or cloud-init status --wait returns before runcmd finishes (which would hand over boxes whose installs are still running) |
open — worth its own issue if run 6 shows cloud-init mid-flight |
Traps this script has already fallen into
Read this before adding a probe. Every one of these cost a run.
-
set -o pipefailbreaks refusal checks. Half the drill isclaudebox <refusal> 2>&1 | grep -q 'text'. The refusal exits 1/2 by design, andgrep -qSIGPIPEs the left side when it matches early. Under pipefail both become false FAILs. The pipeline's verdict must be grep's alone — henceset -uand no pipefail. -
$( )waits for stdout to CLOSE, not for the command to exit. A grandchild inheriting anincus execsession's stdout holds the substitution open forever, andtimeoutdoes not save you: it kills the wrapper, not the process holding the pipe. Usein_box/box_curl, which talk toincus execdirectly, pin stdin to/dev/null, and land output in a file rather than a pipe. -
Never start a background process inside a box. Same mechanism as (2), and it is why the drill now runs no listener anywhere. It does not need one:
curlexit7(refused) means the packet arrived,28(timeout) means it was dropped. A closed port answers the question. -
The box's address is hard to read, and every way of getting it wrong was tried. (a)
incus listname filters are not regexes —incus list "^peer$"silently matches nothing. (b) Its CSV quotes a multi-address box across lines. (c) The interface is noteth0. The profile names the deviceeth0, but inside a VM guest predictable naming renames itenp5s0— soip addr show dev eth0finds nothing either. That is the real reason A3 went unprobed for six runs, through two "fixes" of mine that never questioned the interface name. Read it from inside the box and select by subnet (10.87.x), not by interface name: docker0 (172.17.x) is the decoy, and the NIC's name is the guest's business. Lesson: when the same probe fails three different ways, stop patching the probe and go look at the thing itself. -
incus delete -f a b caborts at the first MISSING name. One interrupted run then poisons the next: stale boxes survive cleanup and cascade into half a dozen unrelated FAILs. Delete one name at a time. -
apt-get -qq … >/dev/nullhides both a sudo prompt and the apt lock.apt-daily/unattended-upgradeshold the lock on a cloud image and apt waits in complete silence. Pre-authorize sudo, setDPkg::Lock::Timeout, and narrate. -
claudebox execissudo -u claude -i— a login zsh with oh-my-zsh. Fine for a human, needless machinery for a probe, and one more thing that can hold an fd. Probes useincus execdirectly. -
Clean before you set up, not after.
setup-host.shreconfigures the network's ACLs, and a previous run's boxes are still attached to that network —incus network setthen has to push the change onto every live NIC. An aborted run also leaves the D-phase mutations (dns.mode=none, NIC filtering) in place, so setup converges against a moving target. Delete the boxes and revert the mutations first. -
Never render a verdict on a broken baseline. Run 7's box had no network (a clone/source IP collision), and phase D dutifully reported "L2 filtering BREAKS the box — design veto". It did not; the box was already broken. A measurement taken on a broken instrument is not evidence, and #16 would have been redesigned around a fiction. Phase D is now gated on baseline egress passing, and refuses to judge otherwise. This is the same failure as the B3 flip, in a different costume: check that the thing you are measuring with still works before you trust what it tells you.
Diagnosing a stall
The drill narrates every long step. If it goes quiet, open a second terminal:
# what is actually running / blocked?
ps -eo pid,etimes,stat,args | grep -Ev grep | grep -E 'apt|dpkg|incus|setup-host|sudo|curl'
# apt lock held by a background upgrade? (the classic silent stall)
sudo fuser -v /var/lib/dpkg/lock-frontend
systemctl status unattended-upgrades apt-daily.service
# incus itself wedged?
incus list
journalctl -u incus --no-pager -n 30
Running one probe by hand
Nothing in the audit requires the whole drill. To answer A3 on a host that
already has two boxes up (archive and peer):
PEER_IP=$(timeout 20 incus exec peer -- ip -4 -o addr show dev eth0 \
| awk '{split($4,a,"/"); print a[1]}')
timeout 30 incus exec archive -- curl -sS -m 5 -o /dev/null "http://$PEER_IP:8088"
echo "curl exit: $?" # 28 = dropped (isolated) · 7 = refused (it ARRIVED) · 0 = connected
timeout 30 incus exec archive -- ping -c1 -W2 "$PEER_IP"
echo "ping exit: $?" # 0 = ICMP replies — isolation is partial at best
No listener is needed, and none should be started: see trap 3.
Run history
| Run | Result | What it cost |
|---|---|---|
| 1 | hung at C7; ~9 false FAILs | traps 1, 2, 4 — pipefail, the exec-pty hang, the DHCP race |
| 2 | 42/49 | trap 5 — an interrupted run 1 left boxes behind, cascading 5 FAILs. Found the claude-on-PATH bug. Phase D delivered B1 (@internal rejected) and a B3 reading of broken |
| 3 | 48/49 | trap 4 — eth0_ip never matched, so A3 again unprobed. B3 now read intact, contradicting run 2 |
| 4 | hung at C4 | trap 2 again, this time via claudebox exec in a command substitution |
| 5 | stalled in host setup | trap 6 — silence through apt/sudo |
| 6 | stalled in setup-host.sh |
trap 8 — cleanup ran after setup. Recovering the host exposed two real claudebox bugs: setup-host deadlocks the incus daemon when re-run with boxes up (#26), and clones inherit their source's machine-id → same DHCP lease → two boxes, one IP (#27) |
| 7 | 41/49 | the clone-identity fix could not reboot (systemd needs a valid machine-id to shut down cleanly), so it never took effect → the IP collision persisted → the box lost networking → phase D reported a false design veto against #16. Trap 9. Also found: dir storage makes every clone a full disk copy (#29) |
The instrument has been less reliable than the thing it measures. Four of five runs died on drill plumbing, not on claudebox. That is worth stating plainly: if a probe can be answered by hand (see above), answer it by hand and move on rather than paying for another full run.
The B3 flip — a lesson worth keeping
Run 2 said dns.mode=none broke egress; run 3 said it was intact. Both
probed ~2s after setting the key, and setting dns.mode restarts the network's
dnsmasq — so run 2 caught the restart window and run 3 missed it. A design veto
was posted to #16 on the strength of run 2, then retracted.
A verdict drawn from one observation of a system with restart semantics is not a verdict. The probe now distinguishes transient (recovers within 30s) from broken (does not), and any test #16 ships must tolerate that window rather than race it.