code: def rpm_install(install_dir):
      
      log = logging.getLogger(mod_logger + '.rpm_install')
  
      # Type checks on the args
      if not isinstance(install_dir, basestring):
          msg = 'install_dir argument must be a string'
          log.error(msg)
          raise CommandError(msg)
  
      # Ensure the install_dir directory exists
      if not os.path.isdir(install_dir):
          msg = 'Directory not found: {f}'.format(f=install_dir)
          log.error(msg)
          raise CommandError(msg)
  
      # Create the command
      command = ['rpm', '-iv', '--force', '{d}/*.rpm'.format(d=install_dir)]
  
      # Run the rpm command
      try:
          result = run_command(command)
      except CommandError:
          raise
      log.info('RPM completed and exit with code: {c}'.format(
          c=result['code']))
      return result['code']
docs: This method installs all RPM files in a specific dir
  
      :param install_dir: (str) Full path to the directory
      :return int exit code form the rpm command
      :raises CommandError