#!/usr/bin/env ruby

require 'yaml'
require 'pp'
require 'optparse'
require 'rubygems'
require 'right_aws'

@options = {}  # OptionParse
@parser = OptionParser.new do |parser|
  parser.banner = "#{File.basename(__FILE__, '.rb')}
    Usage: #{File.basename(__FILE__, '.rb')} [options] args"
  parser.separator "options:"
  parser.on('-s', '--size=SIZE', "EBS Allocate size(GB)") {|v| @options[:size] = v}
  parser.on('-D', '--md-device=DEVICE', "MD Device name") {|v| @options[:md_device] = v}
  parser.on('-L', '--raid-level=LEVEL', "MD Raid level[0 | 1 | 5 | 10]") {|v| @options[:raid_level] = v}
  parser.on('-h', '--help', "show this message") {
    puts parser
    exit
  }
end

TIMEOUT = 180
# AWS Ec2 Env variables
S3CONF_FILE = "#{ENV['HOME']}/.s3conf/s3config.yml"

# Load AWS KEYS
begin
  auth = open(S3CONF_FILE) {|f| YAML.load(f)}
rescue => e
  warn e.pretty_inspect
  warn e.backtrace
  exit 0
else
  ENV['AWS_ACCESS_KEY_ID'] = auth["aws_access_key_id"]
  ENV['AWS_SECRET_ACCESS_KEY'] = auth["aws_secret_access_key"]
  @instance_id = <%= ec2_instance_id %>
  @az = <%= ec2_placement_availability_zone %>
  ENV['EC2_URL'] = "https://ec2.#{@az.chop}.amazonaws.com"

  @ec2 = RightAws::Ec2.new
end

# Wait EBS Volume status
# === Params
#   aws_id  EBS Volume id
#   timeout waiting time
#   status[:name] Wating status name
#   status[:value] Wating status value
def wait_vol_status(aws_id, timeout, status)
  puts "waiting state: #{status.pretty_inspect}"
  Timeout.timeout(timeout) do |i|
    loop do
      sleep 2
      wait_vol = @ec2.describe_volumes(aws_id).first
      break if wait_vol[status[:name]] == status[:value]
      puts "EBS Volume state #{wait_vol[status[:name]]}: waiting..."
    end
    if block_given?
      puts "Check Created Block device"
      loop do
        sleep 2
        break if yield
      end
    end
  end
rescue Timeout::Error => e
  warn e.pretty_inspect
  warn e.backtrace
  puts "EBS Volume #{aws_id} deleting..."
  @ec2.delete_volume(aws_id)
  raise StandardError, "waiting #{status.pretty_inspect} EBS Volume #{aws_id}: Timeout!!"
end

# Create EBS Volume
def create_ebs_volume_with_attach(device_name)
  vol = @ec2.create_volume(nil, @options[:size], @az)  # snapshot_id, size, availability_zone
  puts "Creating EBS Volume #{vol[:aws_id]}..."
  wait_vol_status(vol[:aws_id], TIMEOUT, :name => :aws_status, :value => "available")
  puts "Created EBS Volume #{vol[:aws_id]}: Complete!!"
  result = @ec2.attach_volume(vol[:aws_id], @instance_id, device_name)  # vol_id, instance_id, device_name
  puts "Attaching EBS Volume #{vol[:aws_id]}..."
  wait_vol_status(vol[:aws_id], TIMEOUT, :name => :aws_attachment_status, :value => "attached") {File.blockdev?(device_name)}
  puts "Attached EBS Volume #{vol[:aws_id]}: Complete!!"
rescue => e
  warn e.pretty_inspect
  warn e.backtrace
  puts "EBS Volume #{vol[:aws_id]} deleting..."
  @ec2.delete_volume(vol[:aws_id]) unless vol[:aws_id].nil?
  exit 0
end

# Entory point
# === Params
#   -s, --size  EBS Volume size (GB)
#   -D, --md-device  MD Device name
#   -L, --raid-level  RAID Level[0 | 1 | 5 | 10]
#   ARGV  EBS Mount devices (/dev/sdj, /dev/sdk, /dev/sdl, etc)
# === Examples
#   ruby new_ebs_volume_attach.rb 200 /dev/sdj
if __FILE__ == $0
  @parser.parse!
  if ARGV.size < 1
    warn "No Devieces: Wrong number of arguments (#{ARGV.size} for >=1)"
    exit 0
  end
  # Create EBS Volume with attach instance
  ARGV.each do |dev|
    create_ebs_volume_with_attach(dev)
  end
  # Crate md raid
  if @options.has_key?(:md_device) && @options.has_key?(:raid_level)
    system("/sbin/mdadm -C #{@options[:md_device]} --level=raid#{@options[:raid_level]} --raid-devices=#{ARGV.size} -f #{ARGV.join(' ')}")
  end
end