#!/bin/sh

# PROVIDE: unicorn
# REQUIRE: LOGIN postgresql
# KEYWORD: shutdown

. /etc/rc.subr

name="unicorn"
rcvar="${name}_enable"
procname="ruby"

extra_commands="upgrade show reopenlogs"
start_cmd="unicorn_start_command"
upgrade_cmd="unicorn_upgrade_command"
show_cmd="unicorn_show_command"
reopenlogs_cmd="unicorn_reopenlogs_command"

load_rc_config "${name}"

: ${unicorn_enable:="NO"}
: ${unicorn_flags:="-D"}
: ${unicorn_env:="production"}
: ${unicorn_init_config:=""}
: ${unicorn_bundle_gemfile:=""}
: ${unicorn_profiles:=""}
: ${unicorn_upgrade_timeout:="60"}
: ${unicorn_rc_script:="/usr/local/etc/rc.d/unicorn"}

#
# Convenience function to read a profile's environment variable, or fall back to a default
#
# e.x. _read_profile_var my_app pidfile '/u/my_app/shard/pids/unicorn.pid'
#
_read_profile_var()
{
  profile=$1
  var=$2
  default=$3
  default2=$4
  eval value="\${unicorn_${profile}_${var}:-${default}}"
  eval value="\${value:-${default2}}"
  echo "${value}"
}

#
# Takes a directory and sets up some default environement variables based on a capistrano layout
#
_setup_directory()
{
  local directory
  directory=$1

  directory_command="${directory}/current/bin/unicorn"
  directory_pidfile="${directory}/shared/tmp/pids/unicorn.pid"
  directory_old_pidfile="${directory_pidfile}.oldbin"
  directory_config="${directory}/current/config/unicorn.rb"
  directory_rackup="${directory}/current/config.ru"
  directory_init_config="${directory}/current/.env"
  directory_bundle_gemfile="${directory}/current/Gemfile"
  directory_chdir="${directory}/current"

  # only use the directory_init_config if it exists
  if [ ! -f "${directory_init_config}" ]; then
    unset directory_init_config
  fi

  # only use the bundle_gemfile if it exists
  if [ ! -f "${directory_bundle_gemfile}" ]; then
    unset directory_bundle_gemfile
  fi

  if [ -f "${directory_config}" ]; then
    directory_user=`stat -f "%Su" "${directory_config}"` # default to the owner of the config file
  fi
}

#
# If we have a profile, set up the environment for that profile
#
if [ -n "$2" ]; then
  profile="$2"

  # set the rcvar for this specific profile
  rcvar="${name}_${profile}_enable"
  rcvar="${rcvar}"

  # if the user provides a directory, we can infer some default configuration
  directory=`_read_profile_var "${profile}" "directory"`

  if [ -n "${directory}" ]; then
    _setup_directory "${directory}"
  fi

  unicorn_rackup=`        _read_profile_var "${profile}" "rackup"         "${directory_rackup}"`
  unicorn_old_pidfile=`   _read_profile_var "${profile}" "old_pidfile"    "${directory_old_pidfile}"`
  unicorn_config=`        _read_profile_var "${profile}" "config"         "${directory_config}"`
  unicorn_init_config=`   _read_profile_var "${profile}" "init_config"    "${directory_init_config}"`
  unicorn_bundle_gemfile=`_read_profile_var "${profile}" "bundle_gemfile" "${directory_bundle_gemfile}"`
  unicorn_chdir=`         _read_profile_var "${profile}" "chdir"          "${directory_chdir}"`
  unicorn_listen=`        _read_profile_var "${profile}" "listen"         "${unicorn_listen}"`
  unicorn_user=`          _read_profile_var "${profile}" "user"           "${unicorn_user}"           "${directory_user}"`
  unicorn_nice=`          _read_profile_var "${profile}" "nice"           "${unicorn_nice}"`
  unicorn_env=`           _read_profile_var "${profile}" "env"            "${unicorn_env}"`
  unicorn_flags=`         _read_profile_var "${profile}" "flags"          "${unicorn_flags}"`

  command=`_read_profile_var "${profile}"      "command"      "${unicorn_command}"      "${directory_command}"`
  command_args=`_read_profile_var "${profile}" "command_args" "${unicorn_command_args}" "${directory_command_args}"`
  pidfile=`_read_profile_var "${profile}"      "pidfile"      "${directory_pidfile}"`
else
  if [ "x${unicorn_profiles}" != "x" -a "x$1" != "x" ]; then
    # If we weren't started with a profile, run the command on all available profiles
    for profile in ${unicorn_profiles}; do
      # By default set the profile rcvar to no to suppress warnings by checkyesno
      profile_rcvar="${name}_${profile}_enable"
      eval "${profile_rcvar}=\${${profile_rcvar}:-'NO'}"

      if checkyesno ${profile_rcvar}; then
        echo "Running ${1} on ${profile}"
        ${unicorn_rc_script} $1 $profile
      else
        echo "Skipping ${profile}"

        # Unset the variable and then checkyesno again to print the warning
        eval "unset ${profile_rcvar}"
        checkyesno ${profile_rcvar}
      fi
      echo
    done
    exit 0
  else
    # look for a profile-less configuration

    # if the user provides a directory, we can infer some default configuration
    directory=${unicorn_directory:-}

    if [ -n "${directory}" ]; then
      _setup_directory "${directory}"
    fi

    unicorn_rackup=${unicorn_rackup:-$directory_rackup}
    unicorn_old_pidfile=${unicorn_old_pidfile:-$directory_old_pidfile}
    unicorn_chdir=${unicorn_chdir:-$directory_chdir}
    unicorn_rackup=${unicorn_rackup:-$directory_rackup}
    unicorn_user=${unicorn_user:-$directory_user}
    unicorn_config=${unicorn_config:-$directory_config}
    unicorn_init_config=${unicorn_init_config:-$directory_init_config}
    unicorn_bundle_gemfile=${unicorn_bundle_gemfile:-$directory_bundle_gemfile}

    command=${unicorn_command:-$directory_command}
    command_args=${unicorn_command_args:-$directory_command_args}
    pidfile=${unicorn_pidfile:-$directory_pidfile}
  fi
fi

# add the directory as a required directory, if it's specified
required_dirs="${directory:-}"

# if we have a config file or rackup file specified, make sure it exists
required_files="${unicorn_config:-} ${unicorn_rackup:-}"

#
# Build up the flags based on the environment variables
#
[ -n "${unicorn_listen}" ] && unicorn_flags="-l ${unicorn_listen} ${unicorn_flags}"
[ -n "${unicorn_config}" ] && unicorn_flags="-c ${unicorn_config} ${unicorn_flags}"
[ -n "${unicorn_env}" ] && unicorn_flags="-E ${unicorn_env} ${unicorn_flags}"

# Add our rackup file to the unicorn command_args
[ -n "${unicorn_rackup:-}" ] && command_args="${unicorn_rackup:-} ${command_args:-}"

# This function builds the command to start unicorn. This is split out so we can
# print it from the "show" command
_unicorn_start_command()
{
  local shell_command
  shell_command="${unicorn_bundle_gemfile:+export BUNDLE_GEMFILE=$unicorn_bundle_gemfile && }"\
"${unicorn_init_config:+. $unicorn_init_config && }"\
"${unicorn_chdir:+cd $unicorn_chdir && }"\
"${unicorn_nice:+nice -n $unicorn_nice }"\
"${command} ${rc_flags} ${command_args}"

  if [ -n "${unicorn_user}" ]; then
    echo "su -l ${unicorn_user} -c \"${shell_command}\""
  else
    echo "sh -c \"${shell_command}\""
  fi
}

#
# The start command
#
unicorn_start_command()
{
  # ensure unicorn isn't already running
  if [ -z "$rc_fast" -a -n "$rc_pid" ]; then
    echo 1>&2 "${name} already running? (pid=$rc_pid)."
    return 1
  fi

  # ensure that the command exists and is executable
  if [ ! -x "${_chroot}${_chroot:+/}${command}" ]; then
    warn "run_rc_command: cannot run $command"
    return 1
  fi

  check_startmsgs && echo "Starting ${name}: ${profile}."

  eval "$(_unicorn_start_command)"
  _return=$?

  if [ $_return -ne 0 ] && [ -z "${rc_force}" ]; then
    return 1
  fi

  return 0
}

unicorn_upgrade_command()
{
  if [ -n "${rc_pid}" ]; then
    # Tell the master to spawn a new version of itself
    if kill -USR2 "${rc_pid}"; then
      n=$unicorn_upgrade_timeout

      # Wait until the unicorn_old_pidfile and pidfile both exist and are non-empty
      echo -n >&2 "Waiting for the new master to spawn"
      while [ \( ! -s "${unicorn_old_pidfile}" -o ! -s "${pidfile}" \) -a $n -ge 0 ]; do
        printf >&2 '.' && sleep 1 && n=$(( $n-1 ))
      done
      echo

      # if the pidfile or unicorn_old_pidfile still don't exist, quit
      if [ ! -s "${pidfile}" -o ! -s "${unicorn_old_pidfile}" ]; then
        [ ! -s "${pidfile}" ]              && echo >&2 "${pidfile} doesn't exist after ${unicorn_upgrade_timeout} seconds"
        [ ! -s "${punicorn_old_pidfile}" ] && echo >&2 "${unicorn_old_pidfile} doesn't exist after ${unicorn_upgrade_timeout} seconds"
        return 1
      fi

      # make sure the new master can receive signals, and then QUIT the old one
      echo >&2 "Killing the old master"
      kill -0 `check_pidfile "${pidfile}" "${procname}"` && kill -QUIT `check_pidfile "${unicorn_old_pidfile}" "${procname}"`

      # Wait for the old master to die
      echo -n >&2 "Waiting for the old master to cleanup"
      while [ -s "${unicorn_old_pidfile}" -a $n -ge 0 ]; do
        printf >&2 '.' && sleep 1 && n=$(( $n-1 ))
      done
      echo

      # If the old master is still around, print that fact and exit with an error
      if [ -s "${unicorn_old_pidfile}" -a $n -lt 0 ]; then
        echo >&2 "${unicorn_old_pidfile} still exists after ${unicorn_upgrade_timeout} seconds"
        return 1
      fi

      # everything worked, return success
      return 0
    fi

    # If there isn't a pid in rc_pid, just run the start command
    echo >&2 "Couldn't upgrade, running `start` instead"
    $0 start "${2}"
  fi
}

#
# Prints the configuration for the given profile
#
unicorn_show_command()
{
  if [ -n "${profile}" ]; then
    banner="Unicorn Configuration for ${profile}"
  else
    banner="Unicorn Configuration"
  fi

  echo "
#
# ${banner}
#

command:        ${command}
command_args:   ${command_args}
rackup:         ${unicorn_rackup}
pidfile:        ${pidfile}
old_pidfile:    ${unicorn_old_pidfile}
listen:         ${unicorn_listen}
config:         ${unicorn_config}
init_config:    ${unicorn_init_config}
bundle_gemfile: ${unicorn_bundle_gemfile}
chdir:          ${unicorn_chdir}
user:           ${unicorn_user}
nice:           ${unicorn_nice}
env:            ${unicorn_env}
flags:          ${unicorn_flags}

start_command:

$(_unicorn_start_command)
"
}

unicorn_reopenlogs_command()
{
  [ -n "${rc_pid}" ] && kill -USR1 $rc_pid
}

run_rc_command "${1}"