#!/usr/bin/env bash
## stop-services.sh — sourced by the bash PID-1 entrypoints (entrypoint.sh,
## entrypoint-fpm.sh, entrypoint-shared-httpd.sh). Not executed directly.
##
## Why this exists: those entrypoints end with bash as PID 1 tailing logs.
## The kernel never delivers a signal to PID 1 unless PID 1 installed a handler
## for it, so `docker stop`'s SIGTERM was silently dropped. Docker waited the
## full stop timeout (10s) and then SIGKILLed the whole container, killing
## apache / php-fpm mid-request (exit 137). The entrypoints now trap TERM/INT
## and call stop_service for each daemon they started, then exit 0.
##
## Budget: docker's default stop timeout is 10s. Callers pass per-service
## timeouts that sum to < 10s so the graceful path always completes before
## docker gives up and SIGKILLs.

# A pid counts as alive if it exists and is not a zombie. bash (PID 1) reaps
# the daemons it adopted, but between exit and reap a zombie still answers
# `kill -0`, so check /proc state too.
_svc_alive() {
  [ -n "$1" ] || return 1
  kill -0 "$1" 2>/dev/null || return 1
  ! grep -qs '^State:[[:space:]]*Z' "/proc/$1/status"
}

# stop_service NAME PIDFILE GRACEFUL_SIGNAL GRACE_SECONDS [PGREP_PATTERN]
# Sends GRACEFUL_SIGNAL, waits up to GRACE_SECONDS for the process to exit,
# then sends TERM and waits 1s more, then KILL. Pid comes from PIDFILE, or
# from `pgrep -o -f PGREP_PATTERN` when the pidfile is missing/stale.
stop_service() {
  local name=$1 pidfile=$2 sig=$3 grace=$4 pat=${5:-} pid="" i
  [ -r "$pidfile" ] && pid=$(tr -dc '0-9' < "$pidfile")
  if ! _svc_alive "$pid" && [ -n "$pat" ]; then
    pid=$(pgrep -o -f "$pat" 2>/dev/null)
  fi
  if ! _svc_alive "$pid"; then
    echo "entrypoint: $name not running"
    return 0
  fi
  echo "entrypoint: stopping $name (pid $pid) with SIG$sig"
  kill -s "$sig" "$pid" 2>/dev/null
  for ((i = 0; i < grace * 10; i++)); do
    _svc_alive "$pid" || { echo "entrypoint: $name stopped"; return 0; }
    sleep 0.1
  done
  echo "entrypoint: $name still running after ${grace}s, sending SIGTERM"
  kill -TERM "$pid" 2>/dev/null
  for ((i = 0; i < 10; i++)); do
    _svc_alive "$pid" || { echo "entrypoint: $name stopped"; return 0; }
    sleep 0.1
  done
  echo "entrypoint: $name still running, sending SIGKILL"
  kill -KILL "$pid" 2>/dev/null
  return 0
}