Synnefo » snf-ganeti

# pylint: disable-msg=C0103,W0142

# C0103: Invalid name ganeti-watcher

from ganeti import ssconf

from ganeti import bdev

from ganeti import hypervisor

from ganeti.confd import client as confd_client

class NodeMaintenance(object):

  """Talks to confd daemons and possible shutdown instances/drbd devices.

  """

  def __init__(self):

    self.store_cb = confd_client.StoreResultCallback()

    self.filter_cb = confd_client.ConfdFilterCallback(self.store_cb)

    self.confd_client = confd_client.GetConfdClient(self.filter_cb)

  @staticmethod

  def ShouldRun():

    """Checks whether node maintenance should run.

    """

    try:

      return ssconf.SimpleStore().GetMaintainNodeHealth()

    except errors.ConfigurationError, err:

      logging.error("Configuration error, not activating node maintenance: %s",

                    err)

      return False

  @staticmethod

  def GetRunningInstances():

    """Compute list of hypervisor/running instances.

    """

    hyp_list = ssconf.SimpleStore().GetHypervisorList()

    results = []

    for hv_name in hyp_list:

      try:

        hv = hypervisor.GetHypervisor(hv_name)

        ilist = hv.ListInstances()

        results.extend([(iname, hv_name) for iname in ilist])

      except: # pylint: disable-msg=W0702

        logging.error("Error while listing instances for hypervisor %s",

                      hv_name, exc_info=True)

    return results

  @staticmethod

  def GetUsedDRBDs():

    """Get list of used DRBD minors.

    """

    return bdev.DRBD8.GetUsedDevs().keys()

  @classmethod

  def DoMaintenance(cls, role):

    """Maintain the instance list.

    """

    if role == constants.CONFD_NODE_ROLE_OFFLINE:

      inst_running = cls.GetRunningInstances()

      cls.ShutdownInstances(inst_running)

      drbd_running = cls.GetUsedDRBDs()

      cls.ShutdownDRBD(drbd_running)

    else:

      logging.debug("Not doing anything for role %s", role)

  @staticmethod

  def ShutdownInstances(inst_running):

    """Shutdown running instances.

    """

    names_running = set([i[0] for i in inst_running])

    if names_running:

      logging.info("Following instances should not be running,"

                   " shutting them down: %s", utils.CommaJoin(names_running))

      # this dictionary will collapse duplicate instance names (only

      # xen pvm/vhm) into a single key, which is fine

      i2h = dict(inst_running)

      for name in names_running:

        hv_name = i2h[name]

        hv = hypervisor.GetHypervisor(hv_name)

        hv.StopInstance(None, force=True, name=name)

  @staticmethod

  def ShutdownDRBD(drbd_running):

    """Shutdown active DRBD devices.

    """

    if drbd_running:

      logging.info("Following DRBD minors should not be active,"

                   " shutting them down: %s", utils.CommaJoin(drbd_running))

      for minor in drbd_running:

        # pylint: disable-msg=W0212

        # using the private method as is, pending enhancements to the DRBD

        # interface

        bdev.DRBD8._ShutdownAll(minor)

  def Exec(self):

    """Check node status versus cluster desired state.

    """

    my_name = netutils.Hostname.GetSysName()

    req = confd_client.ConfdClientRequest(type=

                                          constants.CONFD_REQ_NODE_ROLE_BYNAME,

                                          query=my_name)

    self.confd_client.SendRequest(req, async=False, coverage=-1)

    timed_out, _, _ = self.confd_client.WaitForReply(req.rsalt)

    if not timed_out:

      # should have a valid response

      status, result = self.store_cb.GetResponse(req.rsalt)

      assert status, "Missing result but received replies"

      if not self.filter_cb.consistent[req.rsalt]:

        logging.warning("Inconsistent replies, not doing anything")

        return

      self.DoMaintenance(result.server_reply.answer)

    else:

      logging.warning("Confd query timed out, cannot do maintenance actions")

    if NodeMaintenance.ShouldRun():

      NodeMaintenance().Exec()