Ruby script to get the names of compile masters from 'puppet infra'

get_compile_masters.rb

#!/opt/puppetlabs/puppet/bin/ruby
# This script returns an array of compile masters in JSON based on the output of `puppet infra status`.
# Useful for feeding into a task or a plan.

require 'facter'
require 'json'
require 'open3'

def puppet_infra_status
  stdout, _stderr, _status = Open3.capture3('/opt/puppetlabs/puppet/bin/puppet infra status --format json')
  stdout.strip
end

services = JSON.parse(puppet_infra_status)

compile_masters = []
services.each do |service|
  compile_masters << service['server'] if service['service'] == 'pe-master' && service['server'] != Facter.value('fqdn')
end

puts compile_masters.to_json