#!/bin/bash
#
### BEGIN INIT INFO
# Provides:   kube-addons
# Required-Start:    $local_fs $network $syslog kube-apiserver
# Required-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Kubernetes Addon Object Manager
# Description:
#   Enforces installation of Kubernetes Addon Objects
### END INIT INFO


# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="Kubernetes Addon Object Manager"
NAME=kube-addons
DAEMON_LOG_FILE=/var/log/${NAME}.log
PIDFILE=/var/run/${NAME}.pid
SCRIPTNAME=/etc/init.d/${NAME}
KUBE_ADDONS_SH=/etc/kubernetes/kube-addons.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions




#
# Function that starts the daemon/service
#
do_start()
{
    # use setsid to make sure the new daemon has its own group (I suppose
    # start-stop-daemon does create a process group, but let's stay on the
    # safe side).
    setsid start-stop-daemon --start --verbose --background --no-close --make-pidfile --pidfile "${PIDFILE}" --startas "${KUBE_ADDONS_SH}" </dev/null >> ${DAEMON_LOG_FILE} 2>&1
}

#
# Function that stops the daemon/service
#
do_stop()
{
    # start-stop-daemon is not used because we have to stop all children
    # limitations:
    #  - stop does not work if the pid file is missing
    #  - stop does not work if the daemon process is missing (children will not
    #    be killed)
    # This is sufficient - remaining processes will end after a while.

    local pid
    pid=$(cat "${PIDFILE}" 2> /dev/null)
    if [[ $? != 0 ]]; then
        return 1
    fi
    local pgrp
    # find the process group for the service and kill entire group
    #  o - output format: pgpg - process group
    pgrp=$(ps --no-headers --pid "${pid}" -o pgrp 2>/dev/null)
    if [[ $? != 0 ]] || [[ "${pgrp}" == "" ]]; then
        return 1
    fi
    pgrp=$(echo -e ${pgrp})   # strip whitespaces (that's why there are no quotes around pgrp)
    # negative pid is for killing entire group
    kill -- -${pgrp} 2> /dev/null
    if [[ $? != 0 ]]; then
        return 2
    fi
    rm -f "${PIDFILE}"
    return
}

case "$1" in
  start)
        log_daemon_msg "Starting ${DESC}" "${NAME}"
        do_start
        case "$?" in
                0|1) log_end_msg 0 || exit 0 ;;
                2) log_end_msg 1 || exit 1 ;;
        esac
        ;;
  stop)
        log_daemon_msg "Stopping ${DESC}" "${NAME}"
        do_stop
        case "$?" in
                0|1) log_end_msg 0 || exit 0 ;;
                2) log_end_msg 1 || exit 1 ;;
        esac
        ;;
  status)
        status_of_proc -p "${PIDFILE}" "${KUBE_ADDONS_SH}" "${NAME}"
        ;;

  restart|force-reload)
        log_daemon_msg "Restarting ${DESC}" "${NAME}"
        do_stop
        case "$?" in
          0|1)
                do_start
                case "$?" in
                        0) log_end_msg 0 ;;
                        1) log_end_msg 1 ;; # Old process is still running
                        *) log_end_msg 1 ;; # Failed to start
                esac
                ;;
          *)
                # Failed to stop
                log_end_msg 1
                ;;
        esac
        ;;
  *)
        echo "Usage: ${SCRIPTNAME} {start|stop|status|restart|force-reload}" >&2
        exit 3
        ;;
esac