network_api.setup_networks_on_host is called before _instance_update(host=migration_ref['dest_compute']) in compute.manager._finish_resize, thus db.network_get_associated_fixed_ips(host='dest_compute_name') will not return this
instance's DHCP host info in FlatDHCPManager._setup_networks_on_host().
Update instance's host to dest_compute_node_name before setup_networks_on_host would fix this.
The reason is :
network_ api.setup_ networks_ on_host is called before _instance_ update( host=migration_ ref['dest_ compute' ]) in compute. manager. _finish_ resize, thus db.network_ get_associated_ fixed_ips( host='dest_ compute_ name') will not return this ._setup_ networks_ on_host( ).
instance's DHCP host info in FlatDHCPManager
Update instance's host to dest_compute_ node_name before setup_networks_ on_host would fix this.