cap_hiera.rb

require 'hiera'
 
class CapHiera
 
  def self.hiera key, options = {}
 
    scope = {}
 
    if options[:host]
      scope[:host] = options[:host]
      scope[:role] = options[:host].roles.to_a
    end
 
    if options[:stage]
      scope[:stage] = options[:stage]
    else
      scope[:stage] = fetch(:stage)
    end
 
    begin
      @@h ||= Hiera.new({:config => './hiera/hiera.yaml'})
    rescue Exception => e
      STDERR.puts "Failed to start Hiera: #{e.class}: #{e}"
      exit 1
    end
    @@h.lookup(key, 'nil', scope, order_override=nil, resolution_type=:priority)
  end
 
  def self.build_servers_from_stage stage
    servers = CapHiera.hiera('servers', {:stage => stage})
    servers.each do |k,v|
      server k, v
    end
  end
 
end

Capfile

require_relative 'lib/capistrano/cap_hiera'
CapHiera.build_servers_from_stage 'staging'

How did you rewrite this into a module?

EDIT: Found it! https://github.com/jtopjian/capistrano-tutorial/blob/stage3/modules/hiera/lib/cap_hiera.rb

Thanks @jtopjian !