Delayed Job init script; it uses start-stop-daemon and supports every Ruby version manager (RVM, rbenv, chruby...)

delayed_job_init_script.sh

#!/bin/sh
### BEGIN INIT INFO
# Provides: delayed_job
# Required-Start:    $all
# Required-Stop:     $local_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the delayed_job instances
# Description:       starts the delayed_job server instances using start-stop-daemon
#
### END INIT INFO

# Author: https://github.com/mdesantis
# URL:    https://gist.github.com/mdesantis/5143648
#
# This is /etc/init.d/delayed_job (without .sh)
# init.d script for single or multiple delayed_job installations. 
#
# This configures delayed_job for your Rails app.
#
# Its aim is to support delayedjob for every Ruby version manager (rvm, rbenv, chruby...), 
# given the executable bin/delayed_job or script/delayed_job . If it does not, let me know it and I will update this script.
#
# If you have issues with this script, let me know it commenting to this gist:
#
#   https://gist.github.com/mdesantis/5143648
#
# Configuration
# 
# The configuration files of this script must be located in /etc/delayed_job .
# Expects at least one config file.
#
# It is required to specify a configuration file for every delayed_job master instance.
#
# You can disable configuration files appending '.disabled' to their filenames.
#
#
# A sample: /etc/delayed_job/delayed_job:cool_app
#
#   APP_USER=delayed_job
#   APP_NAME=cool_app
#   APP_PATH=/path/to/cool_app
#   APPEND_TO_ENV_PATH=''
#   ADDITIONAL_ENV_VARS='RBENV_VERSION=2.1.0'
#   DELAYED_JOB=/home/delayed_job/.rvm/bin/delayed_job_rails_wrapper
#   RAILS_ENV=development
#   PID_DIR=/path/to/cool_app/shared/pids
#
# You can skip APP_USER and APP_NAME declarations; their values will be inferred by the 
# configuration file name. Also the other variables can be skipped; their values will be setted
# depending on APP_USER and APP_NAME (see below for details)
#
#
# Other samples:
#
# RVM:
#
#   DELAYED_JOB=/home/delayed_job/.rvm/bin/delayed_job_wrapper
#
# rbenv:
#
#   APPEND_TO_ENV_PATH="/home/mau/.rbenv/shims":"/home/mau/.rbenv/bin"
#
# chruby:
#
#   You should create a delayed_job_wrapper with
#
#   #!/bin/sh
#   source /usr/local/share/chruby/chruby.sh && \
#   chruby <ruby_version> && \
#   /path/to/script/delayed_job "$@"
#
#   `chmod +x /path/to/delayed_job_wrapper` and in the configuration file:
#
#   DELAYED_JOB=/path/to/delayed_job_wrapper
#
#
# Inside the configuration file you can set the following variables (defaults are applied when not 
# specified):
#
#   APP_USER             The user which runs the delayed_job server process
#     defaults to        the part before the colon (:) of the configuration file name
#
#   APP_GROUP            The group which runs the delayed_job server process
#     defaults to        <APP_USER>
#  
#   APP_NAME             The application name
#     defaults to        the part after the colon (:) of the configuration file name
#  
#   APP_PATH             The path to the application
#     defaults to        /home/<APP_USER>/www/<APP_NAME>
#  
#   APPEND_TO_ENV_PATH   A list of paths which will be appended to the user path variable
#                        at the delayed_job start
#     defaults to        /home/<APP_USER>/.rbenv/shims:/home/<APP_USER>/.rbenv/bin (yes, I use rbenv)
#  
#   ADDITIONAL_ENV_VARS  Additional enviroment variables in the format
#                        "VAR1=value1 VAR2=value2"
#     defaults to        ''
#  
#   DELAYED_JOB          The path to the delayed_job binary.
#     defaults to        <APP_PATH>/scripts/delayed_job
#  
#   RAILS_ENV            The value which delayed_job will use as environment
#     defaults to        production
#  
#   PID_DIR              The path to the delayed_job PID directory
#     defaults to        <APP_PATH>/tmp/pids
#
#   WORKERS              The amount of the workers spawned by delayed_job
#     defaults to        2
#
#   MONITOR              If not false, sets the "--monitor" option, which spawns a new delayed_job process if one dies
#     defaults to        true
#
# The colon (:) was chosen as user/app_name separator because it is an invalid character
# for UNIX usernames.
#
#
# Usage
#
# If you call this script without any config parameters, it will attempt to run the
# init command for all your delayed_job configurations listed in /etc/delayed_job/* .
#
# /etc/init.d/delayed_job start # starts all delayed_job configurations
#
# If you specify a particular config, it will only operate on that one
#
# /etc/init.d/delayed_job start my_app

PATH=/sbin:/usr/sbin:/bin:/usr/bin

. /lib/init/vars.sh

. /lib/lsb/init-functions

delayed_job_log_end_msg () {
  log_end_msg $1
}

delayed_job_log_daemon_msg () {
  log_daemon_msg $1 "$APP_DESC"
}

set_start_stop_daemon_args () {
  local action args

  action=$1
  shift 1
  args="$@"

  set -- "$action" --quiet --user "$APP_USER" --chuid "$APP_USER:$APP_GROUP" --pidfile "$PIDFILE"

  if [ "$action" = --status ]; then
    START_STOP_DAEMON_ARGS="$@"
    return 0
  fi

  set -- $@ --exec /usr/bin/env PATH="$APPEND_TO_ENV_PATH":"$PATH" $ADDITIONAL_ENV_VARS    \
    RAILS_ENV="$RAILS_ENV" "$DELAYED_JOB" -- --number_of_workers="$WORKERS" $MONITOR $args
  START_STOP_DAEMON_ARGS="$@"

  return 0
}
 
do_start () {
  set_start_stop_daemon_args --status
  start-stop-daemon $START_STOP_DAEMON_ARGS && return 1

  set_start_stop_daemon_args --start start
  start-stop-daemon $START_STOP_DAEMON_ARGS || return 2
}

do_stop () {
  local retval

  set_start_stop_daemon_args --status
  
  start-stop-daemon $START_STOP_DAEMON_ARGS && retval=0 || retval=1

  set_start_stop_daemon_args --start stop
  start-stop-daemon $START_STOP_DAEMON_ARGS > /dev/null || return 2

  return $retval
}

do_reload () {
  set_start_stop_daemon_args --start reload
  start-stop-daemon $START_STOP_DAEMON_ARGS > /dev/null || return 2

  return 0
}

do_restart () {
  set_start_stop_daemon_args --start restart
  start-stop-daemon $START_STOP_DAEMON_ARGS > /dev/null || return 2

  return 0
}

cmd () {
  case "$1" in
    start)
    delayed_job_log_daemon_msg "Starting"
    do_start
    case "$?" in
      0|1) delayed_job_log_end_msg 0 ;;
      *) delayed_job_log_end_msg 1 ;;
    esac
    ;;

    stop)
    delayed_job_log_daemon_msg "Stopping"
    do_stop
    case "$?" in
      0|1) delayed_job_log_end_msg 0 ;;
      2) delayed_job_log_end_msg 1 ;;
    esac
    ;;

    reload|force-reload)
    delayed_job_log_daemon_msg "Reloading"
    do_reload
    log_end_msg $?
    ;;

    restart)
    delayed_job_log_daemon_msg "Restarting"
    do_restart
    log_end_msg $?
    ;;

    status)
    status_of_proc -p $PIDFILE "$DELAYED_JOB" "$APP_DESC"
    ;;

    *)
    echo "Usage: $0 <start|stop|reload|force-reload|restart|status>" >&2
    exit 3
    ;;
  esac
}

unset_variables () {
  unset APP_USER
  unset APP_GROUP
  unset APP_NAME
  unset APP_PATH
  unset APPEND_TO_ENV_PATH
  unset ADDITIONAL_ENV_VARS
  unset BUNDLE_EXEC
  unset DELAYED_JOB
  unset RAILS_ENV
  unset PID_DIR
  unset WORKERS
  unset MONITOR
}

# Read settings or composing default values
setup () {
  CONFIG=$1

  [ -z "$APP_USER" ] && APP_USER=`basename $1 | cut -f 1 -d :`

  [ -z "$APP_GROUP" ] && APP_GROUP="$APP_USER"

  [ -z "$APP_NAME" ] && APP_NAME=`basename $1 | cut -f 2- -d :`
  
  # Displayed inside messages
  APP_DESC="Delayed job - $APP_NAME"
  
  [ -z "$APP_PATH" ] && APP_PATH="/home/$APP_USER/www/$APP_NAME"

  # Check whether the application directory exists
  if [ ! -d "$APP_PATH" ]; then
    log_failure_msg "$APP_DESC: $APP_PATH is not a valid directory"
    return 1
  fi

  [ -z "$APPEND_TO_ENV_PATH" ] && APPEND_TO_ENV_PATH=''

  [ -z "$ADDITIONAL_ENV_VARS" ] && ADDITIONAL_ENV_VARS=''

  if [ -z "$DELAYED_JOB" ]; then
    if [ -f "$APP_PATH/bin/delayed_job" ]; then
      DELAYED_JOB="$APP_PATH/bin/delayed_job"
    else
      DELAYED_JOB="$APP_PATH/script/delayed_job"
    fi
  fi

  [ -z "$RAILS_ENV" ] && RAILS_ENV="production"

  [ -z "$PID_DIR" ] && PID_DIR="$APP_PATH/tmp/pids"

  [ -z "$WORKERS" ] && WORKERS="2"

  [ "$MONITOR" != false ] && MONITOR="--monitor" || MONITOR="" 

  # If workers number is > 1, delayed_job creates a PID_FILE for every worker, naming them
  # as delayed_job.<worker_index>.pid . Since we use PIDFILE just to check whether delayed_job 
  # is started or not, we can use the normal pidfile when the worker is 1, and the pidfile with zero-index
  # in the other cases.
  [ "$WORKERS" = 1 ] && PIDFILE="$PID_DIR/delayed_job.pid" || PIDFILE="$PID_DIR/delayed_job.0.pid"

  return 0
}

# Either run the start/stop/reload/etc command for every config under /etc/delayed_job
# or just do it for a specific one

# $1 contains the start/stop/etc command
# $2 if it exists, should be the specific config we want to act on

if [ $2 ]; then
  # Check whether the conf file is disabled
  
  if ! echo "$2" | grep -qv '\.disabled$'; then
    echo "$2 is disabled. Rename it in order to use it."
    exit 1
  fi

  set -e
  . /etc/delayed_job/$2
  setup "/etc/delayed_job/$2"
  set +e
  cmd $1
else
  FAILURE=0
  for CONFIG in `find /etc/delayed_job -type f -print0 | grep -zv '\.disabled$' | sed "s/\x00/\n/g"`; do
    # clean variables from prev configs
    unset_variables

    . $CONFIG && setup $CONFIG
    if [ "$?" != 0 ]; then
      FAILURE=3
      continue
    fi

    # run the start/stop/etc command
    cmd $1 || FAILURE=3
  done
  exit $FAILURE
fi