opts = Optimist.options do
  opt :ems_id, "The ID of the ExtManagementSystem to reconnect VMs for", :type => :integer
  opt :ems_name, "The name of the ExtManagementSystem to reconnect VMs for", :type => :string
  opt :by, "Property to treat as unique, defaults to :uid_ems", :type => :string, :default => "uid_ems"
  opt :dry_run, "Just print out what would be done without modifying anything", :type => :boolean, :default => true