amdprophet · May 21, 2020 18:03 · May 21, 2020
diff --git a/unifi-sensu-agent-init b/unifi-sensu-agent-init
@@ -0,0 +1,180 @@
+#!/bin/sh
+### BEGIN INIT INFO
+# Provides:          sensu-agent
+# Required-Start:    $remote_fs $syslog
+# Required-Stop:     $remote_fs $syslog
+# Default-Start:     2 3 4 5
+# Default-Stop:      0 1 6
+# Short-Description: Start sensu-agent
+# Description:       Enable the Sensu Agent service
+### END INIT INFO
+
+PATH=/sbin:/usr/sbin:/bin:/usr/bin
+export PATH
+
+name=sensu-agent
+program=/usr/sbin/sensu-agent
+args="start"
+pidfile="/var/run/sensu/$name.pid"
+user="sensu"
+group="sensu"
+chroot="/"
+chdir="/"
+nice=""
+
+
+# If this is set to 1, then when `stop` is called, if the process has
+# not exited within a reasonable time, SIGKILL will be sent next.
+# The default behavior is to simply log a message "program stop failed; still running"
+KILL_ON_STOP_TIMEOUT=0
+
+# Maximum number of open file descriptors.
+MAX_OPEN_FILES=65535
+
+# When loading default and sysconfig files, we use `set -a` to make
+# all variables automatically into environment variables.
+set -a
+[ -r /etc/default/sensu-agent ] && . /etc/default/sensu-agent
+[ -r /etc/sysconfig/sensu-agent ] && . /etc/sysconfig/sensu-agent
+set +a
+
+[ -z "$nice" ] && nice=0
+
+trace() {
+  logger -t "/etc/init.d/sensu-agent" "$@"
+}
+
+emit() {
+  trace "$@"
+  echo "$@"
+}
+
+start() {
+  ulimit -n ${MAX_OPEN_FILES}
+
+  # Setup any environmental stuff beforehand
+
+
+  # Run the program!
+  set +e
+  chroot 2>&1 | grep BusyBox > /dev/null
+  RC=$?
+  set -e
+  if [ "$RC" -eq 0 ] ; then
+    start-stop-daemon -S -q -c $user -b -m \
+      -p $pidfile -x $program -- $args \
+      >> /var/log/sensu/sensu-agent.log 2>&1
+  else
+    chroot --userspec "$user":"$group" "$chroot" sh -c "
+      cd \"$chdir\"
+      ulimit -n ${MAX_OPEN_FILES}
+      exec \"$program\" $args
+      " >> /var/log/sensu/sensu-agent.log 2>&1 &
+  fi
+
+  # Generate the pidfile from here. If we instead made the forked process
+  # generate it there will be a race condition between the pidfile writing
+  # and a process possibly asking for status.
+  echo $! > $pidfile
+
+  emit "$name started"
+  return 0
+}
+
+stop() {
+  # Try a few times to kill TERM the program
+  if status ; then
+    pid=$(cat "$pidfile")
+    trace "Killing $name (pid $pid) with SIGTERM"
+    kill -TERM $pid
+    # Wait for it to exit.
+    for i in 1 2 3 4 5 ; do
+      trace "Waiting $name (pid $pid) to die..."
+      status || break
+      sleep 1
+    done
+    if status ; then
+      if [ "$KILL_ON_STOP_TIMEOUT" -eq 1 ] ; then
+	trace "Timeout reached. Killing $name (pid $pid) with SIGKILL.  This may result in data loss."
+	kill -KILL $pid
+	emit "$name killed with SIGKILL."
+      else
+	emit "$name stop failed; still running."
+      fi
+    else
+      emit "$name stopped."
+    fi
+  fi
+}
+
+status() {
+  if [ -f "$pidfile" ] ; then
+    pid=$(cat "$pidfile")
+    if ps -p $pid > /dev/null 2> /dev/null ; then
+      # process by this pid is running.
+      # It may not be our pid, but that's what you get with just pidfiles.
+      # TODO(sissel): Check if this process seems to be the same as the one we
+      # expect. It'd be nice to use flock here, but flock uses fork, not exec,
+      # so it makes it quite awkward to use in this case.
+      return 0
+    else
+      return 2 # program is dead but pid file exists
+    fi
+  else
+    return 3 # program is not running
+  fi
+}
+
+force_stop() {
+  if status ; then
+    stop
+    status && kill -KILL $(cat "$pidfile")
+  fi
+}
+
+
+case "$1" in
+  force-start|start|stop|force-stop|restart)
+    trace "Attempting '$1' on sensu-agent"
+    ;;
+esac
+
+case "$1" in
+  force-start)
+    PRESTART=no
+    exec "$0" start
+    ;;
+  start)
+    status
+    code=$?
+    if [ $code -eq 0 ]; then
+      emit "$name is already running"
+      exit $code
+    else
+      start
+      exit $?
+    fi
+    ;;
+  stop) stop ;;
+  force-stop) force_stop ;;
+  status)
+    status
+    code=$?
+    if [ $code -eq 0 ] ; then
+      emit "$name is running"
+    else
+      emit "$name is not running"
+    fi
+    exit $code
+    ;;
+  restart)
+
+    stop && start
+    ;;
+  *)
+    echo "Usage: $SCRIPTNAME {start|force-start|stop|force-start|force-stop|status|restart}" >&2
+    exit 3
+  ;;
+esac
+
+exit $?