Synnefo » snf-ganeti » ganeti-local

  def Verify(self, hvparams=None):

    @type hvparams: dict of strings

    @param hvparams: hypervisor parameters to be verified against

    if hvparams is None:

      return "Could not verify the hypervisor, because no hvparams were" \

             " provided."

    if constants.HV_XEN_CMD in hvparams:

      xen_cmd = hvparams[constants.HV_XEN_CMD]

      try:

        self._CheckToolstack(xen_cmd)

      except errors.HypervisorError:

        return "The configured xen toolstack '%s' is not available on this" \

               " node." % xen_cmd

    result = self._RunXen(["info"], hvparams=hvparams)

      return "Retrieving information from xen failed: %s, %s" % \

        (result.fail_reason, result.output)

  def _CheckToolstack(self, xen_cmd):

    """Check whether the given toolstack is available on the node.

    @type xen_cmd: string

    @param xen_cmd: xen command (e.g. 'xm' or 'xl')

    """

    binary_found = self._CheckToolstackBinary(xen_cmd)

    if not binary_found:

      raise errors.HypervisorError("No '%s' binary found on node." % xen_cmd)

    elif xen_cmd == constants.XEN_CMD_XL:

      if not self._CheckToolstackXlConfigured():

        raise errors.HypervisorError("Toolstack '%s' is not enabled on this"

                                     "node." % xen_cmd)

  def _CheckToolstackBinary(self, xen_cmd):

    """Checks whether the xen command's binary is found on the machine.

    """

    if xen_cmd not in constants.KNOWN_XEN_COMMANDS:

      raise errors.HypervisorError("Unknown xen command '%s'." % xen_cmd)

    result = self._run_cmd_fn(["which", xen_cmd])

    return not result.failed

  def _CheckToolstackXlConfigured(self):

    """Checks whether xl is enabled on an xl-capable node.

    @rtype: bool

    @returns: C{True} if 'xl' is enabled, C{False} otherwise

    """

    result = self._run_cmd_fn([constants.XEN_CMD_XL, "help"])

    if not result.failed:

      return True

    elif result.failed:

      if "toolstack" in result.stderr:

        return False

      # xl fails for some other reason than the toolstack

      else:

        raise errors.HypervisorError("Cannot run xen ('%s'). Error: %s."

                                     % (constants.XEN_CMD_XL, result.stderr))