daemon.rb

#!/usr/bin/env jruby
require 'rubygems'
require 'spoon'

APPNAME = 'fileserver'
WORK_PATH = Dir.pwd
EXEC      = "#{ENV['HOME']}/.rbenv/shims/puma"
PID_PATH  = "#{WORK_PATH}/log/#{APPNAME}.pid"
OUT_PATH  = "#{WORK_PATH}/log/#{APPNAME}.out.log"

def create_pid(pid)
  begin
    open(PID_PATH, 'w') do |f|
      f.puts pid
    end
  rescue => e
    STDERR.puts "Error: Unable to open #{PID_PATH} for writing:\n\t" +
        "(#{e.class}) #{e.message}"
    exit!
  end
end

def get_pid
  pid = false
  begin
    open(PID_PATH, 'r') do |f|
      pid = f.readline
      pid = pid.to_s.gsub(/[^0-9]/,'')
    end
  rescue => e
    STDERR.puts "Error: Unable to open #{PID_PATH} for reading:\n\t" +
        "(#{e.class}) #{e.message}"
    exit
  end

  pid.to_i
end

def remove_pidfile
 begin
   File.unlink(PID_PATH)
  rescue => e
    STDERR.puts "ERROR: Unable to unlink #{path}:\n\t" +
      "(#{e.class}) #{e.message}"
    exit
  end
end

def process_exists?
  begin
    pid = get_pid
    return false unless pid
    Process.kill(0, pid)
    true
  rescue Errno::ESRCH, TypeError
    STDERR.puts "PID #{pid} is NOT running or is zombied!";
    false
  rescue Errno::EPERM
    STDERR.puts "No permission to query #{pid}!";
  rescue => e
    STDERR.puts "(#{e.class}) #{e.message}:\n\t" +
      "Unable to determine status for #{pid}."
    false
  end
end

def stop
  begin
    pid = get_pid
    STDERR.puts "pid : #{pid}"
    while true do
      Process.kill("TERM", pid)
      Process.wait(pid)
      sleep(0.1)
    end
    puts "here"
  rescue Errno::ESRCH, Errno::ECHILD # no more process to kill
    remove_pidfile
    STDOUT.puts 'Stopped the process'
  rescue => e
    STDERR.puts "unable to terminate process: (#{e.class}) #{e.message}"
  end
end

def restart
  if process_exists?
    STDERR.puts "The process #{EXEC} already running. Restarting the process"
    stop
  end
  start
end

def start
  Dir::chdir(WORK_PATH)
  file_actions = Spoon::FileActions.new
  file_actions.close(1)
  file_actions.open(1, OUT_PATH, File::WRONLY | File::TRUNC | File::CREAT, 0644)
  spawn_attr =  Spoon::SpawnAttributes.new
  pid = Spoon.posix_spawn EXEC, file_actions, spawn_attr, %w(puma -b tcp://127.0.0.1:9090)
  create_pid(pid)
  Process.setsid
end

if ARGV[0] == 'start'
  start
elsif ARGV[0] == 'stop'
  stop
elsif ARGV[0] == 'restart'
  stop
  start
else
  STDERR.puts "Usage: daemon.rb <start|stop|restart>"
  exit!
end

trantor-fileserver.conf

# Upstart script for FileServer
# Copy to /etc/init/ (root:root, 644)
# usage   : (start|stop) trantor-fileserver
# logfile : /var/log/upstart/trantor-fileserver.log
#
description "FileServer web app: Puma+Sinatra+Rack"
author "Nando Sola<nando@abstra.cc>"
start on started runsvdir
stop on runlevel [!5]
respawn

pre-start script
  rm -rf /var/trantor/tmp/*
end script

script
  . /etc/profile.d/puma.sh
  APP_NAME="trantor-fileserver"
  APP_ROOT="/apps/$APP_NAME/current"
  LISTEN="tcp://127.0.0.1:9090"
  THREAD_POOL="1:16"
  TRANTOR_FILESERVER_CONFIG_DIR="/apps/$APP_NAME/shared/config"
  TMPDIR="/var/trantor/tmp"
  JAVA_OPTS=$JAVA_OPTS
  export TRANTOR_FILESERVER_CONFIG_DIR TMPDIR JAVA_OPTS

  EXEC_CMD="puma -b $LISTEN -t $THREAD_POOL"

  sudo -u puma -s -- <<EOF
cd $APP_ROOT
$JRUBY_HOME/bin/jruby -S bundle exec puma -b $LISTEN -t $THREAD_POOL
EOF
end script

#post-stop script
#end script