Generic Linux service script, systemd and LSB compatible but also working on older systems

service_script.sh

#!/bin/bash

# Generic Linux service script, systemd and LSB compatible but also working on older systems

# To install:
# 1. Place under /etc/init.d/ with the name of the service
# 2. sudo chmod +x /etc/init.d/my_service
# 3. sudo systemctl enable my_service || sudo chkconfig --add my_service
# 4. sudo service my_service start

### BEGIN INIT INFO
# Provides:          my_service
# Required-Start:    $network
# Required-Stop:     $network
# Should-Start:      $named $syslog
# Should-Stop:       $named $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: My service
### END INIT INFO

# For (old?) RedHat distros:
# chkconfig: 2345 20 80

# http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html
# http://www.thegeekstuff.com/2012/03/lsbinit-script

# Using the lsb functions if available...
LSB=/lib/lsb/init-functions
if [[ -r $LSB ]]; then
  . $LSB
else
  # Otherwise make stubs based on RedHat-style chkconfig/init.d
  unset LSB
  . /etc/init.d/functions
  if type echo_success &>/dev/null; then
    log_success_msg() { echo_success; echo "$@"; }
    log_warning_msg() { echo_warning; echo "$@"; }
    log_failure_msg() { echo_failure; echo "$@"; }
  else
    log_success_msg() { echo "SUCCESS: $@"; }
    log_warning_msg() { echo "WARNING: $@"; }
    log_failure_msg() { echo "FAILURE: $@"; }
  fi
fi

# Process name ( For display )
NAME=my_service

# Daemon name, where is the actual executable
SERVICE_HOME=/opt/my_service

DAEMON="$SERVICE_HOME/my_service"
test -x $DAEMON || exit 5 # Program not installed

PIDFILE=/var/run/my_service.pid
LOGFILE=/var/log/my_service.log

# Configuration options
SERVICE_OPTIONS="--config \"$SERVICE_HOME/my_service.conf\""

#TODO: Run with non-root user / downgrade privileges

# Multi-platform status method. Silent on LSB
status() {
  if [[ ! -e $PIDFILE ]]; then
    [[ ! $LSB ]] && echo "my_service is not running"
    return 3
  elif [[ -e /proc/$(cat "$PIDFILE" 2>/dev/null) ]]; then
    [[ ! $LSB ]] && echo "my_service is running"
    return 0
  fi
  [[ ! $LSB ]] && log_warning_msg "my_service is dead"
  return 1
}

start() {
  if (status &>/dev/null); then
    log_success_msg "my_service already started"
    return 0
  fi
  parse_options
  nohup "$DAEMON" "${SERVICE_OPTIONS[@]}" >>"$LOGFILE" 2>&1 &
  echo $! > $PIDFILE
  sleep .5 # Give it some time to fail if port already taken etc.
  if (status &>/dev/null); then
    log_success_msg "my_service started"
    return 0
  fi
  log_failure_msg "my_service FAILED to start (status=$?)"
  rm -f $PIDFILE
  return 1
}

stop() {
  if (status &>/dev/null); then
    PID=$(cat "$PIDFILE" 2>/dev/null)
    kill $PID
    sleep .1
    WAIT=0
    while [[ -e /proc/$PID ]]; do
      log_warning_msg "Waiting for my_service to finish..."
      if [[ $((++WAIT)) -ge 3 ]]; then
        log_failure_msg "Cannot stop my_service"
        return 1
      fi
      sleep 1
    done
  fi
  if (rm -f $PIDFILE &>/dev/null); then
    log_success_msg "my_service is stopped"
    return 0
  fi
  log_warning_msg "Cannot remove $PIDFILE"
  return 1
}

case "$1" in
    start)
        #LSB: start_daemon -n 1 -p "$pidfile" "$DAEMON"
        start
        ;;
    stop)
        #LSB: killproc -p "$pidfile" "$DAEMON"
        stop
        ;;
    restart)
        stop
        start
        ;;
    reload)
        echo "Not implemented" >&2
        exit 1
        ;;
    status)
        #LSB: pidofproc -p "$pidfile" "$DAEMON"
        status
        state=$?
        # On non-LSB systems, provide at least basic process info
        [[ ! $LSB && $state == 0 ]] && ps wup $(cat "$PIDFILE" ) 2>/dev/null
        exit $state
        ;;
    *)
        echo "Usage: $0 {start|stop|status|restart}" >&2
        exit 1
esac