Claude
171b3947dd
Captain Bob, 2026-11-07: 'Limit guests and have a Busy, try back in a few minutes.' start-session.sh takes one of DEMO_MAX_GUESTS slots (default 2), a lock it holds for the session's life (flock -n: two visitors cannot both take the last one; QEMU and the bridge are started without its descriptor); with every slot taken, the visitor's terminal says every machine is busy and to try back in a few minutes, and the session ends without a machine. The service: DEMO_MAX_GUESTS=2, RuntimeDirectory for the locks, ttyd's --max-clients 6 so a visitor over the limit reaches the message. The guest: 384 MiB (v4 boots from 256 MiB, refuses at 128; measured, #116). Tested here: every slot held -> the busy message; slot 1 held -> slot 2 taken. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GE3SDvQn5EoxdGufk84zz2
64 lines
3.2 KiB
Bash
Executable File
64 lines
3.2 KiB
Bash
Executable File
#!/bin/bash
|
|
# start-session.sh -- one visitor's session: the saved demo machine, resumed at its prompt, its
|
|
# serial console on this terminal; gone when the visitor leaves or the time is up (issue #112).
|
|
# ttyd runs this once per browser connection (issue #114).
|
|
#
|
|
# demo/start-session.sh [state-dir] (default: /var/lib/starshipos-demo)
|
|
#
|
|
# Nothing a visitor does survives the session: the firmware variables are a copy, the identity
|
|
# drive's writes are discarded, the image is read-only, and the guest has no network.
|
|
set -euo pipefail
|
|
here=$(cd "$(dirname "$0")" && pwd)
|
|
. "$here/qemu-args.sh"
|
|
dir=${1:-${DEMO_STATE:-/var/lib/starshipos-demo}}
|
|
limit=${DEMO_SESSION_LIMIT:-1800} # seconds a session may last
|
|
guests=${DEMO_MAX_GUESTS:-2} # machines at once: 384 MiB each (qemu-args.sh, #116)
|
|
slots=${DEMO_SLOTS:-/run/starshipos-demo} # a lock file per machine
|
|
|
|
[ -f "$dir/state" ] || { echo "The demo is not set up yet: no saved machine in $dir." >&2; exit 1; }
|
|
|
|
# One of $guests slots, or a busy message (Captain Bob, 2026-11-07: "Limit guests and have a Busy,
|
|
# try back in a few minutes"). A slot is a lock this script holds for the session's life (flock -n:
|
|
# two visitors cannot both take the last one); it goes when the script does, however it ends. The
|
|
# machine's processes are started without the lock's descriptor ({slot}>&-), so it is this
|
|
# script's alone.
|
|
mkdir -p "$slots"
|
|
slot=
|
|
for i in $(seq 1 "$guests"); do
|
|
exec {fd}>"$slots/slot-$i.lock"
|
|
if flock -n "$fd"; then slot=$fd; break; fi
|
|
exec {fd}>&-
|
|
done
|
|
if [ -z "$slot" ]; then
|
|
printf '\r\nEvery StarshipOS machine is busy right now (%d at once on this small server).\r\n' "$guests"
|
|
printf 'Try back in a few minutes.\r\n'
|
|
sleep 20
|
|
exit 0
|
|
fi
|
|
tmp=$(mktemp -d "${TMPDIR:-/tmp}/starshipos-session.XXXXXX")
|
|
trap 'rm -rf "$tmp"' EXIT
|
|
cp "$dir/vars.fd" "$tmp/vars.fd"
|
|
demo_qemu_args "$dir" "$tmp/vars.fd"
|
|
|
|
printf '\r\nStarshipOS -- starting a throwaway machine, yours for up to %d minutes. Nothing you do is kept.\r\n' $((limit / 60))
|
|
printf 'Try: 3 4 + . : SQUARE DUP * ; 7 SQUARE .\r\n\r\n'
|
|
# QEMU is a tracked child, not exec'd, so that whatever ends the session ends the machine: ttyd
|
|
# hangs up (it signals this script only), the service stops, or the time runs out. Its console is
|
|
# a private socket, joined to this terminal by console.py only once the machine runs: keys typed
|
|
# while it loads would be lost half-way through a line.
|
|
qemu-system-x86_64 "${QEMU_ARGS[@]}" \
|
|
-chardev "socket,id=con,path=$tmp/con.sock,server=on,wait=off" -serial chardev:con \
|
|
-qmp "unix:$tmp/qmp.sock,server=on,wait=off" -monitor none \
|
|
-incoming "file:$dir/state" </dev/null {slot}>&- &
|
|
qemu=$!
|
|
( sleep "$limit"; kill "$qemu" 2>/dev/null ) {slot}>&- &
|
|
timer=$!
|
|
# The bridge is a tracked child too: bash runs a trap only once its foreground command returns,
|
|
# so a hang-up would otherwise wait on the bridge. `wait` returns to the trap at once.
|
|
python3 -I "$here/console.py" "$tmp/qmp.sock" "$tmp/con.sock" 0<&0 {slot}>&- &
|
|
bridge=$!
|
|
trap 'kill "$bridge" "$qemu" "$timer" 2>/dev/null; rm -rf "$tmp"' EXIT
|
|
trap 'exit 0' HUP TERM INT
|
|
wait "$bridge" || true
|
|
printf '\r\n\r\nThe session has ended. Reload the page for a new one.\r\n'
|