gistfile1.rb

# Way to parse knife exec options....
# knife exec example.rb option:value option:value
# Gets converted to --option value --option value

require 'awesome_print'
require 'trollop'

def convert_input(arguments)
  arguments.reject do |option|
    option !~ /^[a-z]+:[a-z]{2,}-*[a-z]*-*\d*$/
  end.map do |option|
    opt, value = option.split(':')
    [ '--' + opt, value ]
  end.flatten
end

parser = Trollop::Parser.new do
  opt :region, "Region to use", :default => "eu-west-1"
  opt :release, "Release name", :default => "lucid"
  opt :group, "Security group", :default => "default"
  opt :size, "Size of instance", :default => "small"
  opt :key, "Name of AWS keypair", :default => "gsg-opseng"
  opt :ebs, "Should the instance be EBS backed?", :default => "no"
end

opts = Trollop::with_standard_exception_handling parser do
  converted_args = convert_input(ARGV)
  raise Trollop::HelpNeeded if converted_args.empty? # show help screen
  o = parser.parse converted_args 
  o
end

ap opts

exit 0