Synnefo » snf-ganeti

def _RunXmList(fn, xmllist_errors):

  """Helper function for L{_GetXmList} to run "xm list".

  @type fn: callable

  @param fn: Function returning result of running C{xm list}

  @type xmllist_errors: list

  @param xmllist_errors: Error list

  @rtype: list

  """

  result = fn()

  if result.failed:

    logging.error("xm list failed (%s): %s", result.fail_reason,

                  result.output)

    xmllist_errors.append(result)

    raise utils.RetryAgain()

  # skip over the heading

  return result.stdout.splitlines()

def _ParseXmList(lines, include_node):

  """Parses the output of C{xm list}.

  @type lines: list

  @param lines: Output lines of C{xm list}

  @type include_node: boolean

  @param include_node: If True, return information for Dom0

  @return: list of tuple containing (name, id, memory, vcpus, state, time

    spent)

  """

  result = []

  # Iterate through all lines while ignoring header

  for line in lines[1:]:

    # The format of lines is:

    # Name      ID Mem(MiB) VCPUs State  Time(s)

    # Domain-0   0  3418     4 r-----    266.2

    data = line.split()

    if len(data) != 6:

      raise errors.HypervisorError("Can't parse output of xm list,"

                                   " line: %s" % line)

    try:

      data[1] = int(data[1])

      data[2] = int(data[2])

      data[3] = int(data[3])

      data[5] = float(data[5])

    except (TypeError, ValueError), err:

      raise errors.HypervisorError("Can't parse output of xm list,"

                                   " line: %s, error: %s" % (line, err))

    # skip the Domain-0 (optional)

    if include_node or data[0] != _DOM0_NAME:

      result.append(data)

  return result

def _GetXmList(fn, include_node, _timeout=5):

  """Return the list of running instances.

  See L{_RunXmList} and L{_ParseXmList} for parameter details.

  """

  xmllist_errors = []

  try:

    lines = utils.Retry(_RunXmList, (0.3, 1.5, 1.0), _timeout,

                        args=(fn, xmllist_errors))

  except utils.RetryTimeout:

    if xmllist_errors:

      xmlist_result = xmllist_errors.pop()

      errmsg = ("xm list failed, timeout exceeded (%s): %s" %

                (xmlist_result.fail_reason, xmlist_result.output))

    else:

      errmsg = "xm list failed"

    raise errors.HypervisorError(errmsg)

  return _ParseXmList(lines, include_node)

  def _GetXmList(include_node):

    """Wrapper around module level L{_GetXmList}.

    # TODO: Abstract running Xen command for testing

    return _GetXmList(lambda: utils.RunCmd([constants.XEN_CMD, "list"]),

                      include_node)

    xm_list = self._GetXmList(False)

    xm_list = self._GetXmList(instance_name == _DOM0_NAME)

    xm_list = self._GetXmList(False)

    for (name, _, mem, vcpus, _, _) in self._GetXmList(True):