Monitoring & Logging: fix transfer_link sent by receiver. Closes ruci…

…o#5640

Under normal operation, when we get a notification from FTS about a
transfer completion, we know about the transfer and retrieve it
from the database. It doesn't cost us anything to use the
request.external_host field from the db table, which has the correct
format.

We can ignore the occurances when it's not the case. It means that we
got a notification from FTS about a transfer submitted by rucio, but
about which rucio doesn't know anything.... we would have bigger
problems to investigate in such case than a wrong monitoring link.

lib/rucio/tests/test_conveyor.py

@@ -469,6 +469,7 @@ def test_multisource_receiver(vo, did_factory, replica_client, root_account, met
         assert msg_submitted['payload']['request-id'] == request['id']
         msg_done = next(msg for msg in msgs if msg['event_type'] == 'transfer-done')
         assert msg_done['payload']['request-id'] == request['id']
+        assert msg_done['payload']['transfer_link'].startswith('https://fts:8449/')
     finally:
         receiver_graceful_stop.set()
         receiver_thread.join(timeout=5)

lib/rucio/transfertool/fts3.py

@@ -355,6 +355,7 @@ def __init__(self, external_host, request_id, request=None):
         # Initialized in child class initialize():
         self._reason = None
         self._src_rse = None
+        self._fts_address = self.external_host
         # Supported db fields bellow:
         self.state = None
         self.external_id = None
@@ -390,7 +391,7 @@ def get_monitor_msg_fields(self, session, logger=logging.log):
         return fields
 
     def _transfer_link(self):
-        return '%s/fts3/ftsmon/#/job/%s' % (self.external_host.replace('8446', '8449'), self._transfer_id)
+        return '%s/fts3/ftsmon/#/job/%s' % (self._fts_address.replace('8446', '8449'), self._transfer_id)
 
     def _find_attribute_updates(self, request, new_state, reason, overwrite_corrupted_files):
         attributes = None
@@ -511,6 +512,7 @@ def initialize(self, session, logger=logging.log):
 
                 self._reason = reason
                 self._src_rse = src_rse_name
+                self._fts_address = request['external_host'] or self._fts_address
 
                 self.state = new_state
                 self.external_id = transfer_id