Files
OpenFUT/scripts/systemd/openfut-wait-tcp.sh
T
funman300 8ae432223a ops: systemd supervision for Core and the FIFA17 host (staging-proven)
Replaces the detached `setsid nohup … nsenter …` launch, which had no restart
policy, no boot persistence and no supervisor-visible logs. Staging units are
installed and proven; production units are TEMPLATES and are not installed.

Three decisions, each measured rather than assumed:

* `Wants=`, not `Requires=`, from host to Core. With `Requires`, stopping Core
  stopped the host AND a later Core start did not bring it back -- a routine
  Core restart would leave the client with no server. With `Wants` the host
  survives a Core outage, answers 503 core_unavailable, never falls back to
  Python, and resumes the moment Core returns with no intervention. Both halves
  tested.
* Readiness is a bounded ExecStartPre TCP gate, because ordering proves nothing
  about readiness and Type=exec only proves the binary exec'd. Core binds its
  listener after migrations and content load, so "port open" is a real signal.
  The gate FAILS rather than blocking: a host that waits forever looks healthy
  while serving nobody.
* The netns is resolved by container NAME every start. The container is
  restart=unless-stopped and its netns inode CHANGES on restart (measured:
  4026539938 -> 4026540033), so a hardcoded pid is wrong by construction and
  anything left in the old namespace serves nobody. Proven equivalent to today's
  nsenter against a scratch container, never production's namespace.

`systemd-analyze verify` caught two real defects before deployment:
StartLimitIntervalSec/StartLimitBurst sat in [Service], where systemd 252
silently ignores them, so the crash-loop ceiling was not taking effect; and a
Documentation URL containing %20 parsed as a specifier. Both fixed and the
effective properties re-confirmed from the running units.

Staging evidence: Core-first ordering, host refused when Core is absent or
merely not listening, outage survival, automatic recovery, restart, graceful
stop with no strays, boot simulated via multi-user.target, 3x SIGKILL contained
at ~5s spacing, journald logs, and economy state byte-identical throughout
(integrity ok, fk 0).
2026-08-22 20:46:15 +00:00

43 lines
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Executable File

#!/bin/sh
# Bounded wait for a TCP listener. Exits 0 as soon as it connects, 1 on timeout.
#
# Used as the FIFA17 host's ExecStartPre so the host cannot start "successfully"
# while Core is absent. A TCP connect is a MEANINGFUL readiness signal here, not
# a guess: openfut-core binds its listener only after it has opened the
# database, run migrations and loaded the content pack — the startup log order
# is `Running database migrations` -> `Loaded N cards` -> `Listening`, and the
# 2026-08-22 promotion demonstrated it directly when a bind collision aborted a
# Core that had already applied migration 0028. So "port open" implies
# "migrations done, content loaded".
#
# Deliberately no retry-forever: a host that blocks indefinitely looks healthy
# to a supervisor while serving nothing. It fails, and the restart policy
# decides what happens next.
#
# usage: openfut-wait-tcp.sh <host> <port> <timeout-seconds>
set -eu
HOST="${1:?host}"
PORT="${2:?port}"
TIMEOUT="${3:-30}"
i=0
while [ "$i" -lt "$TIMEOUT" ]; do
# /dev/tcp is a bash-ism; use a portable connect instead.
if command -v nc >/dev/null 2>&1; then
nc -z "$HOST" "$PORT" 2>/dev/null && exit 0
else
python3 - "$HOST" "$PORT" <<'PY' && exit 0
import socket, sys
s = socket.socket()
s.settimeout(1)
sys.exit(0 if s.connect_ex((sys.argv[1], int(sys.argv[2]))) == 0 else 1)
PY
fi
i=$((i + 1))
sleep 1
done
echo "openfut-wait-tcp: $HOST:$PORT did not accept connections within ${TIMEOUT}s" >&2
exit 1