RVM, Wrapper, Unicorn, Init.d

my_app.conf

NAME="My App"
APP_PATH="/var/apps/my_app/current"
UNICORN="/usr/local/rvm/wrappers/my_app/unicorn_rails"
ENVIRONMENT="production"

unicorn.sh

#!/usr/bin/env bash

### BEGIN INIT INFO
# Provides: unicorn
# Required-Start: $all
# Required-Stop: $network $local_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start the unicorns at boot
# Description: Enable at boot time.
### END INIT INFO

# This is unicorn init.d script for single or multiple unicorn installations.
#
# Expects at least one configuration (*.conf) in `/etc/unicorn`.
#
# A sample configuration (`/etc/unicorn/my_app.conf`):
#
# NAME="My App"
# APP_PATH="/var/apps/my_app/current"
# UNICORN="/usr/local/rvm/wrappers/my_app/unicorn_rails"
# ENVIRONMENT="production"
#
# This configures an Unicorn master for your app at `/var/apps/my_app/current`
# running in production mode. It will read `config/unicorn/<ENVIRONMENT>.rb` for
# further set up.
#
# To get the Unicorn script run:
#
# $ <rvmsudo> rvm alias create <WRAPPER_NAME> <RUBY>@<GEMSET>
# $ rvm wrapper <WRAPPER_NAME> --no-links unicorn_rails
#
# This way it will allow changing the alias when a new  uby is used without
# changing anything else.
#
# You should ensure different ports or sockets are set if you are running more
# than one master concurrently.
#
# If you call this script without any config parameters, it will attempt to run
# the init command for all your unicorn configurations listed in `/etc/unicorn/*.conf`.
#
# $ /etc/init.d/unicorn start # Starts all Unicorns
#
# If you specify a particular config, it will only operate on that one.
#
# $ /etc/init.d/unicorn start <APP_NAME>

__sig() {
  typeset __pid

  [[ -s "$2" ]] && __pid="$(cat "$2")" && [[ -n "${__pid}" ]] && kill -$1 "${__pid}" >/dev/null 2>&1 || return $?
}

sig() {
  __sig "$1" "$PID" || return $?
}

oldsig() {
  __sig "$1" "$OLD_PID" || return $?
}

run() {
  echo -n "$1 - "

  shift

  if
    "$@"
  then
    echo "OK"
  else
    typeset result=$?

    echo "Failed!" >&2

    return $result
  fi
}

prefix_command_with_su_fix_quoting() {
  typeset -a __temp

  __temp=()

  while
    (( $# ))
  do
    __temp+=( "'$1'" )

    shift
  done

  CMD=( su - "${__owner}" -c "cd '$APP_PATH' && ${__temp[*]}" )
}

setup () {
  echo "$NAME:"

  cd $APP_PATH || return $?

  # export RACK_ENV="${ENVIRONMENT}"
  # export RAILS_ENV="${ENVIRONMENT}"
  export PID="$APP_PATH/tmp/pids/unicorn.pid"
  export OLD_PID="$PID.oldbin"

  CMD=( "$UNICORN" -c "${APP_PATH}/config/unicorn/${ENVIRONMENT}.rb" -E "${ENVIRONMENT}" -D )

  typeset __owner="$(stat -c "%U" "${APP_PATH}")"

  if
    [[ "${USER:=$(whoami)}" == "${__owner}" ]]
  then
    true # It's all fine we run as owner of the app
  elif
    (( UID == 0 ))
  then
    prefix_command_with_su_fix_quoting "${CMD[@]}"
  else
    echo "ERROR: running not as owner(${__owner}) of '$APP_PATH' and not as root($USER), prefix with 'sudo' and try again!"

    return 2
  fi
}

cmd_start() {
  if sig 0
  then echo "Already started"
  else run "Starting" "${CMD[@]}" || return $?
  fi
}

wait_pid_kill() {
  typeset __count=$1
  while
    (( __count > 0 )) &&
    sig 0
  do
    : $(( __count-- ))
    sleep 1s
  done
  sig 0 || return $?
}

cmd_stop() {
  run "Stopping" sig QUIT
  if
    wait_pid_kill 5
  then
    run "Force stop" sig TERM
    if wait_pid_kill 3
    then return 1
    fi
  fi
}

cmd_restart() {
  cmd_stop && cmd_start || return $?
}

cmd_reload() {
  run "Reloading" sig USR2 && wait_pid_kill 5 && oldsig QUIT || oldsig TERM || cmd_restart || return $?
}

cmd_rotate() {
  run "Rotate" sig USR1 || cmd_start || return $?
}

cmd() {
  setup || return $?

  case "$1" in
    start|stop|restart|reload|rotate)
      cmd_$1 || return $?
      ;;
    upgrade)
      cmd_reload || return $?
      ;;
    *)
      echo "Usage: $0 <start|stop|restart|reload|upgrade|rotate>" >&2
      return 1
      ;;
  esac
}

# Either run the start, stop, reload, etc. command for every config under
# `/etc/unicorn` or just do it for a specific one.
# $1 contains the command
# $2 if it exists, should be the specific config we want to act on
start_stop () {
  if
    [[ -n "$2" ]]
  then
    . "/etc/unicorn/$2.conf" || return $?
    cmd "$1" || return $?
  else
    for CONFIG in /etc/unicorn/*.conf
    do
      . "$CONFIG" || return $?

      cmd "$1" || return $?
    done
   fi
}

start_stop "$@"

• https://github.com/wayneeseguin/rvm/blob/master/contrib/unicorn_init.sh
• http://rvm.io/integration/init-d
• https://gist.github.com/killercup/2049606
• https://gist.github.com/mpapis/5136395
• https://gist.github.com/mpapis/5136390