Synnefo

#

# Utility functions

#

# Various functions

#

# Copyright 2010 Greek Research and Technology Network

#

from synnefo.db.models import VirtualMachine

from synnefo.logic import credits

import synnefo.settings as settings

def id_from_instance_name(name):

    """Returns VirtualMachine's Django id, given a ganeti machine name.

    Strips the ganeti prefix atm. Needs a better name!

    """

    if not str(name).startswith(settings.BACKEND_PREFIX_ID):

        raise VirtualMachine.InvalidBackendIdError(str(name))

    ns = str(name).lstrip(settings.BACKEND_PREFIX_ID)

    if not ns.isdigit():

        raise VirtualMachine.InvalidBackendIdError(str(name))

    return int(ns)

def get_rsapi_state(vm):

    """Returns the RSAPI state for a virtual machine"""

    try:

        r = VirtualMachine.RSAPI_STATE_FROM_OPER_STATE[vm.operstate]

    except KeyError:

        return "UNKNOWN"

    # A machine is DELETED if the deleted flag has been set

    if vm.deleted:

        return "DELETED"

    # A machine is in REBOOT if an OP_INSTANCE_REBOOT request is in progress

    if r == 'ACTIVE' and vm.backendopcode == 'OP_INSTANCE_REBOOT' and \

        vm.backendjobstatus in ('queued', 'waiting', 'running'):

        return "REBOOT"

    return r

def update_state(vm, new_operstate):

    """Wrapper around updates of the VirtualMachine.operstate field"""

    # Call charge() unconditionally before any change of

    # internal state.

    credits.charge(vm)

    vm.operstate = new_operstate