Unicorn Control Script with some Princess Bride Sprinkled in.

unicorn_control.sh

#!/usr/bin/env bash
# Modified for Rails 3 by Dave Southard January 17th, 2012
# Now with more princess bride!

RAILS_ENV=production
APP_ROOT=/var/rails/unicorn/$1
CURRENT_APP=$APP_ROOT/current
PID=/etc/unicorn/pids/$1.pid
OLD_PID=$PID.oldbin
START_COMMAND="bundle exec unicorn -D -E $RAILS_ENV -c /etc/unicorn/conf/$1.conf"

# Messages
MSG_INFO="Usage: $0 <start|stop|restart|force-stop>"
MSG_START_PREP="As you wish!\nAttempting to start $1."
MSG_START_SUCC="$1 has been successfully started."
MSG_START_FAIL="Couldn't start $1. Giving up and exiting."
MSG_START_EXIT="$1 is running . Exiting."
MSG_STOP_PREP="Aaasssss youuuuu wissssssh!\n Stopping $1."
MSG_STOP_SUCC="$1 successfully stopped!"
MSG_STOP_FAIL="Couldn't stop $1."
MSG_STOP_NOT_RUNNING="$1 is not running."
MSG_STOP_FORCE="Aaasssss youuuuu wissssssh!\n Forcing $1 to stop."
MSG_RESTART_PREP="Attempting restart of $1."
MSG_RESTART_SUCC="Restart was successful."
MSG_RESTART_FAIL="Couldn't restart $1."
MSG_RESTART_ELSE_01="App $1 was not running! Attempting a start."
MSG_STG_01_PREP="Stage 1: Bringing down the house."
MSG_STG_01_SUCC="Stage 1: Complete. Boy did I kill! The old code has been de-staged."
MSG_STG_01_FAIL="borked in the USR2 sig."
MSG_STG_02_PREP="Stage 2: Storm the castle."
MSG_STG_02_SUCC="Stage 2:\n My name is Inigo Montoya.\n You killed my father.\n Prepare to die!\n Old worker processes dying...\n\n"
MSG_STG_02_FAIL="Stage 2: Borked in the WINCH phase of oldsig."
MSG_STG_03_PREP="Stage 3: New Dread Pirate Robbins."
MSG_STG_03_SUCC="Stage 3: The new dread pirate is in place. Enjoy the vacation!"
MSG_STG_03_FAIL="Stage 3: BORKED in the QUIT oldsig."
MSG_NO_SUCH_APP="There is no such app."
RVM_NOT_FOUND="ERROR: An RVM installation was not found.\n"

#. /home/webteam/.bashrc
# Load RVM into a shell session *as a function*
if [[ -s "$HOME/.rvm/scripts/rvm" ]] ; then
  # First try to load from a user install
  source "$HOME/.rvm/scripts/rvm"
elif [[ -s "/usr/local/rvm/scripts/rvm" ]] ; then
  # Then try to load from a root install
  source "/usr/local/rvm/scripts/rvm"
else
  printf $RVM_NOT_FOUND >&2
  exit 1
fi

if [ -s $CURRENT_APP ]; then
  cd $CURRENT_APP
else
  echo -e $MSG_NO_SUCH_APP 1>&2
  exit 1
fi

sig () {
  test -s $PID && kill -$1 `cat $PID`
}

oldsig () {
  test -s $OLD_PID && kill -$1 `cat $OLD_PID`
}

case $2 in
  start)
    echo -e $MSG_START_PREP
    (sig 0) || (echo -e >&2 $MSG_START_EXIT && exit 1)
    $START_COMMAND
    (sig 0 && echo -e $MESSAGE_START ) || (echo -e >&2 $MSG_START_FAIL && exit 1)
    ;;
  stop)
    echo -e $MSG_STOP_PREP
    sig QUIT && exit 0
    echo -e >&2 $MSG_STOP_NOT_RUNNING
    ;;
  force-stop)
    echo -e $MSG_STOP_FORCE
    (sig TERM && echo -e $MSG_STOP_SUCC && exit 0) || (echo -e >&2 $MSG_STOP_FAIL && exit 1)
    echo -e >&2 $MSG_STOP_FAIL
    ;;
  restart|reload)
    echo -e $MSG_RESTART_PREP
    if sig 0; then
      echo -e $MSG_STG_01_PREP
      (sig USR2 && echo -e $MSG_STG_01_SUCC) || (echo -e >&2 $MSG_STG_01_FAIL && exit 1)
      echo -e $MSG_STG_02_PREP
      (oldsig WINCH && echo -e $MSG_STG_02_SUCC) || (echo -e >&2 $MSG_STG_02_FAIL && exit 1)
      echo -e $MSG_STG_03_PREP
      (oldsig QUIT && echo -e $MSG_STG_03_SUCC && echo -e $MSG_RESTART_SUCC) || (echo -e >&2 $MSG_STG_03_FAIL && exit 1)
    else
      echo -e $MSG_RESTART_ELSE_01
      cd $CURRENT_APP && $START_COMMAND && echo -e $MSG_START_SUCC && exit 0
      echo -e >&2 $MSG_RESTART_FAIL && exit 1
    fi
    exit 0
    ;;
  *)
    echo -e >&2 $MSG_INFO && exit 1
  ;;
esac