theforeman/foreman_maintain

module ForemanMaintain
  module Concerns
    module OsFacts
      OS_RELEASE_FILE = '/etc/os-release'.freeze
      FALLBACK_OS_RELEASE_FILE = '/usr/lib/os-release'.freeze

      def os_release_file
        if File.file?(OS_RELEASE_FILE)
          return OS_RELEASE_FILE
        elsif File.file?(FALLBACK_OS_RELEASE_FILE)
          return FALLBACK_OS_RELEASE_FILE
        else
          puts "The #{OS_RELEASE_FILE} and #{FALLBACK_OS_RELEASE_FILE} files are missing! "\
               "Can't continue the execution without Operating System's facts!"
          exit 1
        end
      end

      def facts
        unless defined?(@facts)
          @facts = {}
          regex = /^(["'])(.*)(\1)$/
          File.open(os_release_file) do |file|
            file.readlines.each do |line|
              line.strip! # drop any whitespace, including newlines from start and end of the line
              next if line.start_with?('#') # ignore comments
              # split at most into 2 items, if the value ever contains an =
              key, value = line.split('=', 2)
              next unless key && value
              @facts[key] = value.gsub(regex, '\2').delete('\\')
            end
          end
        end
        @facts
      end

      def os_version_id
        facts.fetch('VERSION_ID')
      end

      def os_id
        facts.fetch('ID')
      end

      def os_id_like_list
        facts.fetch('ID_LIKE', '').split
      end

      def os_name
        facts.fetch('NAME')
      end

      def el?
        File.exist?('/etc/redhat-release')
      end

      def el8?
        el_major_version == 8
      end

      def debian?
        os_id == 'debian'
      end

      def ubuntu?
        os_id == 'ubuntu'
      end

      def el_major_version
        os_version_id.to_i if el?
      end

      def deb_major_version
        os_version_id.to_i if debian?
      end

      def ubuntu_major_version
        os_version_id if ubuntu?
      end

      def debian_or_ubuntu?
        debian? || ubuntu?
      end

      def os_version
        facts.fetch('VERSION')
      end

      def os_version_codename
        facts.fetch('VERSION_CODENAME')
      end

      def rhel?
        os_id == 'rhel'
      end

      def centos?
        os_id == 'centos'
      end

      def el_short_name
        "el#{el_major_version}"
      end

      def memory
        meminfo = File.read('/proc/meminfo')
        meminfo.match(/^MemTotal:\s+(?<memory>\d+) kB/)['memory']
      end

      def cpu_cores
        execute('nproc')
      end
    end
  end
end