unicorn.sh

#!/bin/bash

### BEGIN INIT INFO
# Provides:          unicorn
# Required-Start:    $local_fs $remote_fs $network $syslog nginx
# Required-Stop:     $local_fs $remote_fs $network $syslog nginx
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts unicorn
# Description:       starts unicorn web app servers
### END INIT INFO

signal_app() {
  [[ -s "/opt/$2/$3/current/tmp/pids/unicorn.pid" ]] && kill -$1 `cat "/opt/$2/$3/current/tmp/pids/unicorn.pid"`
}

stop_app() {
  signal_app "QUIT" "$1" "$2"
}

start_app() {
  mkdir -p /var/run/unicorn
  chmod 777 /var/run/unicorn
  local app_root="/opt/$1/$2/current"
  if [[ -d "$app_root" ]]; then
    local inner_command="cd \"$app_root\" && bundle exec unicorn_rails -D -E $2 -c \"$app_root/config/unicorn.rb\""
    nohup sudo -H -u "$1" -i "rvm-shell ree@$1 -c '$inner_command'" >/dev/null 2>&1 &
  fi
}

restart_app() {
  signal_app "USR2" "$1" "$2"
}

action_for_env() {
  "${1}_app" "$2" "$3"
}

default_app_names() {
  if [[ -f "/etc/unicorn.default" ]]; then
    cat "/etc/unicorn.default"
  fi
}

envs_for_app() {
  local action="$1"; shift
  local app_name="$1"; shift
  if [[ "$#" -gt 0 ]]; then
    for env in "$@"; do
      action_for_env "$action" "$app_name" "$env"
    done
  else
    if [[ -d "/opt/$app_name" ]]; then
      for dir in $(\ls "/opt/$app_name"); do
        if [[ -L "/opt/$app_name/$dir/current" && -s "/opt/$app_name/$dir/current/config/unicorn.rb" ]]; then
          action_for_env "$action" "$app_name" "$dir"
        fi
      done
    fi
  fi
}

for_apps() {
  local action="$1"; shift
  users="${1:-"$(default_app_names)"}"; shift
  for user in $users; do
    envs_for_app "$action" "$user" "$@"
  done
}

usage() {
  echo 'Usage: /etc/init.d/unicorn {start,stop,restart} [app] [env]' >&2
  exit 1
}

action="$1"; shift
case "$action" in
  start|stop|restart) for_apps "$action" "$@" ;;
  *) usage ;;
esac