kmod.rb

# frozen_string_literal: true

# @summary Return a hash of loaded kernel modules

Facter.add(:kmods) do
  confine kernel: :linux

  kmod = {}

  setcode do
    if File.exist?('/sys/module')
      Dir.foreach('/sys/module') do |directory|
        next if ['.', '..'].include?(directory)

        kmod[directory] = {
          'parameters' => {},
          'used_by' => [],
        }

        if File.directory?("/sys/module/#{directory}/parameters")
          Dir.foreach("/sys/module/#{directory}/parameters") do |param|
            next if ['.', '..'].include?(param)

            next unless File.readable?("/sys/module/#{directory}/parameters/#{param}")

            begin
              kmod[directory]['parameters'][param] = File.read("/sys/module/#{directory}/parameters/#{param}").chomp
            rescue StandardError
              # some kernel parameters are write only
              # even though they have the read bit set
              # so just ignore read errors
              nil
            end
          end
        end

        if File.directory?("/sys/module/#{directory}/holders")
          Dir.foreach("/sys/module/#{directory}/holders") do |used|
            next if ['.', '..'].include?(used)

            kmod[directory]['used_by'] << used
          end
        end
      end

      kmod
    else
      Facter.debug('/sys/module is not found. skipping.')
    end
  end
end