xos/synchronizer/model_policies/model_policy_Network.py

from synchronizers.new_base.modelaccessor import *
from collections import defaultdict
from synchronizers.new_base.policy import Policy

class NetworkPolicy(Policy):
    model_name = "Network"

    def handle_create(self, network):
        return self.handle_update(network)

    def handle_update(self, network):
        # network controllers are not visible to users. We must ensure
        # networks are deployed at all deploymets available to their slices.

        # TODO: should be possible to query only the ControllerSlice objects
        #       associated with network.owner rather than iterating through
        #       all ControllerSlice.

        slice_controllers = ControllerSlice.objects.all()
        slice_deploy_lookup = defaultdict(list)
        for slice_controller in slice_controllers:
            slice_deploy_lookup[slice_controller.slice.id].append(slice_controller.controller)

        network_controllers = ControllerNetwork.objects.all()
        network_deploy_lookup = defaultdict(list)
        for network_controller in network_controllers:
            network_deploy_lookup[network_controller.network.id].append(network_controller.controller.id)

        expected_controllers = slice_deploy_lookup[network.owner.id]
        for expected_controller in expected_controllers:
            if network.id not in network_deploy_lookup or expected_controller.id not in network_deploy_lookup[network.id]:
                lazy_blocked=True

                # check and see if some instance already exists
                for networkslice in network.networkslices.all():
                    found = False
                    for instance in networkslice.slice.instances.all():
                       if instance.node.site_deployment.controller.id == expected_controller.id:
                           found = True
                    if found:
                       self.logger.info("MODEL_POLICY: network %s setting lazy_blocked to false because instance on controller already exists" % network)
                       lazy_blocked=False

                nd = ControllerNetwork(network=network, controller=expected_controller, lazy_blocked=lazy_blocked)
                self.logger.info("MODEL POLICY: network %s create ControllerNetwork %s lazy_blocked %s" % (network, nd, lazy_blocked))
                if network.subnet:
                    # XXX: Possibly unpredictable behavior if there is
                    # more than one ControllerNetwork and the subnet
                    # is specified.
                    nd.subnet = network.subnet
                nd.save()