Check the current license count against puppetdb

current_license_usage.rb

#!/opt/puppetlabs/puppet/bin/ruby

require 'puppet'
require 'puppet/util/puppetdb'
require 'uri'
require 'json'
require 'yaml'


# Have puppet parse its config so we can call its settings
Puppet.initialize_settings


# Connect to the first puppetdb in the HA array
uri = URI(Puppet::Util::Puppetdb.config.server_urls.first)
server = uri.host
port = uri.port

# All active nodes ( basically the default )
query   = ["and", ["=", ["node","active"], true]]
headers = {'Accept' => 'application/json'}

connection = Puppet::Network::HttpPool.http_instance(server,port,true)
body = connection.get("/pdb/query/v4/nodes?query=#{query.to_json}",headers).body

begin
  response = JSON.load(body)
rescue
  response = body
end

license_key = YAML.load_file('/etc/puppetlabs/license.key') rescue {}


if response.is_a?(Array)
  output = {
    :total_node_count         => response.count,
    :licensed_node_count      => license_key['nodes'],
    :unlicensed_node_count    => license_key['nodes'].to_i - response.count,
  }
  puts output.to_json
else
  puts response
end

I would do

license_key = YAML.load_file('/etc/puppetlabs/license.key') rescue {}

for robustness.