Synnefo » snf-ganeti

def _CheckNodeHasOS(lu, node, os_name, force_variant):

  """Ensure that a node supports a given OS.

  @param lu: the LU on behalf of which we make the check

  @param node: the node to check

  @param os_name: the OS to query about

  @param force_variant: whether to ignore variant errors

  @raise errors.OpPrereqError: if the node is not supporting the OS

  """

  result = lu.rpc.call_os_get(node, os_name)

  result.Raise("OS '%s' not in supported OS list for node %s" %

               (os_name, node),

               prereq=True, ecode=errors.ECODE_INVAL)

  if not force_variant:

    _CheckOSVariant(result.payload, os_name)

def _CheckOSVariant(os_obj, name):

  """Check whether an OS name conforms to the os variants specification.

  @type os_obj: L{objects.OS}

  @param os_obj: OS object to check

  @type name: string

  @param name: OS name passed by the user, to check for validity

  """

  variant = objects.OS.GetVariant(name)

  if not os_obj.supported_variants:

    if variant:

      raise errors.OpPrereqError("OS '%s' doesn't support variants ('%s'"

                                 " passed)" % (os_obj.name, variant),

                                 errors.ECODE_INVAL)

    return

  if not variant:

    raise errors.OpPrereqError("OS name must include a variant",

                               errors.ECODE_INVAL)

  if variant not in os_obj.supported_variants:

    raise errors.OpPrereqError("Unsupported OS variant", errors.ECODE_INVAL)