utils/vmbox/--help
Krzysztof kuhy Rudnicki 0b1f86ae2c vmbox: add a serial transport so shutdown tests do not depend on sshd
The Arch cloud image leaves sshd enabled but never started -- no start line,
no failure line, dependencies satisfied. Four hypotheses (NTP, cloud-init
clean, a socket-disable, a blocking start) were each disproven by measurement,
so rather than keep paying a ~10 min rebuild per guess this adds the transport
the tool should arguably have used all along.

For the case vmbox exists for, serial beats ssh on the merits: it keeps
printing straight through the poweroff that kills an ssh connection, and it
works when sshd does not. `vm run` now picks ssh when it answers and the
serial console otherwise, and recovers the guest exit code either way. Guests
get a second serial port (ttyS1) on a unix socket with a root autologin, kept
separate from ttyS0 so driving a shell never interleaves with the append-only
log the verdict is read from.

serial_exec.py waits for an explicit per-command end marker rather than a
fixed sleep. That is not a detail: an earlier probe used a 4s window, the next
command was typed while the previous one still ran, and the tty echoed that
input -- which reads exactly like output in a transcript and produced a
confident but wrong conclusion. It also strips ANSI CSI and systemd's OSC 3008
shell-integration blocks, verified against a real captured boot log.

Also: a vmbox-sshd-kick unit that forces sshd up after multi-user.target as
belt and braces, and the smoke-test sandbox renamed to a name that actually
passes validate_vm_name -- "__smoke" was rejected, so the gate silently never
ran.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
2026-08-22 20:58:22 +02:00
..
sockets.target.wants vmbox: add a serial transport so shutdown tests do not depend on sshd 2026-08-22 20:58:22 +02:00
sshd-unix-local.socket vmbox: add a serial transport so shutdown tests do not depend on sshd 2026-08-22 20:58:22 +02:00
sshd-unix-local@.service vmbox: add a serial transport so shutdown tests do not depend on sshd 2026-08-22 20:58:22 +02:00