+ async def Relate(self, ns_name, vnfd):
+ """Create a relation between the charm-enabled VDUs in a VNF.
+
+ The Relation mapping has two parts: the id of the vdu owning the endpoint, and the name of the endpoint.
+
+ vdu:
+ ...
+ relation:
+ - provides: dataVM:db
+ requires: mgmtVM:app
+
+ This tells N2VC that the charm referred to by the dataVM vdu offers a relation named 'db', and the mgmtVM vdu has an 'app' endpoint that should be connected to a database.
+
+ :param str ns_name: The name of the network service.
+ :param dict vnfd: The parsed yaml VNF descriptor.
+ """
+
+ # Currently, the call to Relate() is made automatically after the
+ # deployment of each charm; if the relation depends on a charm that
+ # hasn't been deployed yet, the call will fail silently. This will
+ # prevent an API breakage, with the intent of making this an explicitly
+ # required call in a more object-oriented refactor of the N2VC API.
+
+ configs = []
+ vnf_config = vnfd.get("vnf-configuration")
+ if vnf_config:
+ juju = vnf_config['juju']
+ if juju:
+ configs.append(vnf_config)
+
+ for vdu in vnfd['vdu']:
+ vdu_config = vdu.get('vdu-configuration')
+ if vdu_config:
+ juju = vdu_config['juju']
+ if juju:
+ configs.append(vdu_config)
+
+ def _get_application_name(name):
+ """Get the application name that's mapped to a vnf/vdu."""
+ vnf_member_index = 0
+ vnf_name = vnfd['name']
+
+ for vdu in vnfd.get('vdu'):
+ # Compare the named portion of the relation to the vdu's id
+ if vdu['id'] == name:
+ application_name = self.FormatApplicationName(
+ ns_name,
+ vnf_name,
+ str(vnf_member_index),
+ )
+ return application_name
+ else:
+ vnf_member_index += 1
+
+ return None
+
+ # Loop through relations
+ for cfg in configs:
+ if 'juju' in cfg:
+ if 'relation' in juju:
+ for rel in juju['relation']:
+ try:
+
+ # get the application name for the provides
+ (name, endpoint) = rel['provides'].split(':')
+ application_name = _get_application_name(name)
+
+ provides = "{}:{}".format(
+ application_name,
+ endpoint
+ )
+
+ # get the application name for thr requires
+ (name, endpoint) = rel['requires'].split(':')
+ application_name = _get_application_name(name)
+
+ requires = "{}:{}".format(
+ application_name,
+ endpoint
+ )
+ self.log.debug("Relation: {} <-> {}".format(
+ provides,
+ requires
+ ))
+ await self.add_relation(
+ ns_name,
+ provides,
+ requires,
+ )
+ except Exception as e:
+ self.log.debug("Exception: {}".format(e))
+
+ return
+