Synnefo

#

# Business Logic for communication with the Ganeti backend

#

# Copyright 2010 Greek Research and Technology Network

#

from django.conf import settings

from django.db import transaction

from synnefo.db.models import VirtualMachine, Network, NetworkLink

from synnefo.logic import utils

from synnefo.util.rapi import GanetiRapiClient

rapi = GanetiRapiClient(*settings.GANETI_CLUSTER_INFO)

def process_op_status(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' and VirtualMachine.OPER_STATE_FROM_OPCODE[opcode] is not None:

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

        # Set the deleted flag explicitly, to cater for admin-initiated removals

        if opcode == 'OP_INSTANCE_REMOVE':

            vm.deleted = True

    # Special case: if 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()

@transaction.commit_on_success

def process_net_status(vm, nics):

    """Process a net status notification from the backend

    Process an incoming message from the Ganeti backend,

    detailing the NIC configuration of a VM instance.

    Update the state of the VM in the DB accordingly.

    """

    vm.nics.all().delete()

    for i, nic in enumerate(nics):

        if i == 0:

            net = Network.objects.get(public=True)

        else:

            try:

                link = NetworkLink.objects.get(name=nic['link'])

            except NetworkLink.DoesNotExist:

                # Cannot find an instance of NetworkLink for

                # the link attribute specified in the notification

                raise NetworkLink.DoesNotExist("Cannot find a NetworkLink "

                    "object for link='%s'" % nic['link'])

            net = link.network

            if net is None:

                raise Network.DoesNotExist("NetworkLink for link='%s' not "

                    "associated with an existing Network instance." %

                    nic['link'])

        vm.nics.create(

            network=net,

            index=i,

            mac=nic.get('mac', ''),

            ipv4=nic.get('ip', ''))

    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.DeletedError

    # No actions to machines being built. They may be destroyed, however.

    if vm.operstate == 'BUILD' and action != 'DESTROY':

        raise VirtualMachine.BuildingError

    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()

def create_instance(vm, flavor, image, password):

    nic = {'ip': 'pool', 'mode': 'routed', 'link': settings.GANETI_PUBLIC_LINK}

    return rapi.CreateInstance(

        mode='create',

        name=vm.backend_id,

        disk_template='plain',

        disks=[{"size": 4000}],     #FIXME: Always ask for a 4GB disk for now

        nics=[nic],

        os='image+default',

        ip_check=False,

        name_check=False,

        pnode=rapi.GetNodes()[0],   #TODO: use a Ganeti iallocator instead

        dry_run=settings.TEST,

        beparams=dict(auto_balance=True, vcpus=flavor.cpu, memory=flavor.ram),

        osparams=dict(img_id=image.backend_id, img_passwd=password,

                      img_format=image.format))

def delete_instance(vm):

    start_action(vm, 'DESTROY')

    rapi.DeleteInstance(vm.backend_id, dry_run=settings.TEST)

    vm.nics.all().delete()

def reboot_instance(vm, reboot_type):

    assert reboot_type in ('soft', 'hard')

    rapi.RebootInstance(vm.backend_id, reboot_type, dry_run=settings.TEST)

def startup_instance(vm):

    start_action(vm, 'START')

    rapi.StartupInstance(vm.backend_id, dry_run=settings.TEST)

def shutdown_instance(vm):

    start_action(vm, 'STOP')

    rapi.ShutdownInstance(vm.backend_id, dry_run=settings.TEST)

def get_instance_console(vm):

    return rapi.GetInstanceConsole(vm.backend_id)

def request_status_update(vm):

    return rapi.GetInstanceInfo(vm.backend_id)

def get_job_status(jobid):

    return rapi.GetJobStatus(jobid)

def update_status(vm, status):

    utils.update_state(vm, status)

def create_network_link():

    try:

        last = NetworkLink.objects.order_by('-index')[0]

        index = last.index + 1

    except IndexError:

        index = 1

    if index <= settings.GANETI_MAX_LINK_NUMBER:

        name = '%s%d' % (settings.GANETI_LINK_PREFIX, index)

        return NetworkLink.objects.create(index=index, name=name,

                                          available=True)

    # FIXME: Shouldn't something at least be logged here?

    return None     # All link slots are filled

@transaction.commit_on_success

def create_network(name, owner):

    try:

        link = NetworkLink.objects.filter(available=True)[0]

    except IndexError:

        link = create_network_link()

        if not link:

            return None

    network = Network.objects.create(

        name=name,

        owner=owner,

        state='ACTIVE',

        link=link)

    link.network = network

    link.available = False

    link.save()

    return network

@transaction.commit_on_success

def delete_network(net):

    link = net.link

    if link.name != settings.GANETI_NULL_LINK:

        link.available = True

        link.network = None

        link.save()

    for vm in net.machines.all():

        disconnect_from_network(vm, net)

        vm.save()

    net.state = 'DELETED'

    net.save()

def connect_to_network(vm, net):

    nic = {'mode': 'bridged', 'link': net.link.name}

    rapi.ModifyInstance(vm.backend_id,

        nics=[('add', nic)],

        dry_run=settings.TEST)

def disconnect_from_network(vm, net):

    nics = vm.nics.filter(network__public=False).order_by('index')

    new_nics = [nic for nic in nics if nic.network != net]

    if new_nics == nics:

        return      # Nothing to remove

    ops = [('remove', {})]

    for i, nic in enumerate(new_nics):

        ops.append((i + 1, {

            'mode': 'bridged',

            'link': nic.network.link.name}))

    rapi.ModifyInstance(vm.backend_id, nics=ops, dry_run=settings.TEST)