def migrate_backends(self):
""" Migrate the backends of the backend service one by one
without deleting or recreating the backend service
Args:
backend_service_configs: the configs of the backend service
"""
if 'backends' not in self.backend_service.backend_service_configs:
return None
backends = self.backend_service.backend_service_configs['backends']
for i in range(len(backends)):
backend = backends[i]
migration_helper = SelfLinkExecutor(
self.compute, backend['group'], self.network, self.subnetwork,
self.preserve_instance_external_ip)
backend_migration_handler = migration_helper.build_instance_group_migration_handler(
)
# The backend type is not an instance group, then just ignore
if backend_migration_handler == None:
continue
self.backend_migration_handlers.append(backend_migration_handler)
print('Detaching: %s' % (backend['group']))
self.backend_service.detach_a_backend(backend['group'])
print('Migrating: %s' % (backend['group']))
backend_migration_handler.network_migration()
print('Reattaching: %s' % (backend['group']))
self.backend_service.reattach_all_backends()
# wait for the first backend becoming healthy,
# then continue migrate other backends
if i == 0 and len(backends) > 1:
self.backend_service.wait_for_backend_become_healthy(
backend['group'])
def build_instance_group_migration_handlers(self):
""" Use instance group's selfLinks to create a list of
InstanceGroupMigrationHandler
Returns:
"""
for selfLink in self.target_pool.attached_managed_instance_groups_selfLinks:
executor = SelfLinkExecutor(self.compute, selfLink, self.network,
self.subnetwork,
self.preserve_instance_external_ip)
try:
instance_group_migration_handler = executor.build_instance_group_migration_handler(
)
if instance_group_migration_handler != None:
self.instance_group_migration_handlers.append(
instance_group_migration_handler)
except HttpError as e:
if 'not found' in e._get_reason():
continue
else:
raise e