Synnefo

#

# Business Logic for communication with the Ganeti backend

#

# Copyright 2010 Greek Research and Technology Network

#

from synnefo.db.models import VirtualMachine

from synnefo.logic import utils

def process_backend_msg(vm, jobid, opcode, status, logmsg):

    """Process a job progress notification from the backend.

    Process an incoming message from the backend (currently Ganeti).

    Job notifications with a terminating status (sucess, error, or canceled),

    also update the operating state of the VM.

    """

    if (opcode not in [x[0] for x in VirtualMachine.BACKEND_OPCODES] or

       status not in [x[0] for x in VirtualMachine.BACKEND_STATUSES]):

        raise VirtualMachine.InvalidBackendMsgError(opcode, status)

    vm.backendjobid = jobid

    vm.backendjobstatus = status

    vm.backendopcode = opcode

    vm.backendlogmsg = logmsg

    # Notifications of success change the operating state

    if status == 'success':

        utils.update_state(vm, VirtualMachine.OPER_STATE_FROM_OPCODE[opcode])

    # Special cases OP_INSTANCE_CREATE fails --> ERROR

    if status in ('canceled', 'error') and opcode == 'OP_INSTANCE_CREATE':

        utils.update_state(vm, 'ERROR')

    # Any other notification of failure leaves the operating state unchanged

    vm.save()

def start_action(vm, action):

    """Update the state of a VM when a new action is initiated."""

    if not action in [x[0] for x in VirtualMachine.ACTIONS]:

        raise VirtualMachine.InvalidActionError(action)

    # No actions to deleted and no actions beside destroy to suspended VMs

    if vm.deleted:

        raise VirtualMachine.InvalidActionError(action)

    vm.action = action

    vm.backendjobid = None

    vm.backendopcode = None

    vm.backendjobstatus = None

    vm.backendlogmsg = None

    # Update the relevant flags if the VM is being suspended or destroyed

    if action == "DESTROY":

        vm.deleted = True

    elif action == "SUSPEND":

        vm.suspended = True

    elif action == "START":

        vm.suspended = False

    vm.save()