[CHANGED] User cluster ID as part of internal subscriptions

We were using a NUID for subjects such as `_STAN.pub.<nuid>.>`
when running in standalone mode without channel partitioning.

In all other cases, we used the cluster ID in place of the nuid.
This change will make use of the cluster ID in all cases. This
will apply only to new deployment, meaning that existing stores
with NUID in the subjects will still be used.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

server/server.go

@@ -1952,12 +1952,11 @@ func (s *StanServer) start(runningState State) error {
 	} else {
 		s.log.Noticef("No recovered state")
 	}
-	subjID := s.opts.ID
-	// In FT or with static channels (aka partitioning), we use the cluster ID
-	// as part of the subjects prefix, not a NUID.
-	if runningState == Standalone && s.partitions == nil {
-		subjID = nuid.Next()
-	}
+	// We used to use a NUID as part of the internal subjects in standalone mode
+	// without channel partitioning. In all other cases, we used the cluster ID.
+	// We now always use the cluster ID. It makes it easier when users want to
+	// use NATS permissions to restrict things.
+	clusterID := s.opts.ID
 	if recoveredState != nil {
 		// Copy content
 		s.info = *recoveredState.Info
@@ -1970,7 +1969,7 @@ func (s *StanServer) start(runningState State) error {
 		// If not, it means we recovered from an older server, so
 		// need to update.
 		if s.info.SubClose == "" {
-			s.info.SubClose = fmt.Sprintf("%s.%s", DefaultSubClosePrefix, subjID)
+			s.info.SubClose = fmt.Sprintf("%s.%s", DefaultSubClosePrefix, clusterID)
 			// Update the store with the server info
 			callStoreInit = true
 		}
@@ -2004,13 +2003,13 @@ func (s *StanServer) start(runningState State) error {
 		s.info.ClusterID = s.opts.ID
 
 		// Generate Subjects
-		s.info.Discovery = fmt.Sprintf("%s.%s", s.opts.DiscoverPrefix, s.info.ClusterID)
-		s.info.Publish = fmt.Sprintf("%s.%s", DefaultPubPrefix, subjID)
-		s.info.Subscribe = fmt.Sprintf("%s.%s", DefaultSubPrefix, subjID)
-		s.info.SubClose = fmt.Sprintf("%s.%s", DefaultSubClosePrefix, subjID)
-		s.info.Unsubscribe = fmt.Sprintf("%s.%s", DefaultUnSubPrefix, subjID)
-		s.info.Close = fmt.Sprintf("%s.%s", DefaultClosePrefix, subjID)
-		s.info.AcksSubs = fmt.Sprintf("%s.%s", defaultAcksPrefix, subjID)
+		s.info.Discovery = fmt.Sprintf("%s.%s", s.opts.DiscoverPrefix, clusterID)
+		s.info.Publish = fmt.Sprintf("%s.%s", DefaultPubPrefix, clusterID)
+		s.info.Subscribe = fmt.Sprintf("%s.%s", DefaultSubPrefix, clusterID)
+		s.info.SubClose = fmt.Sprintf("%s.%s", DefaultSubClosePrefix, clusterID)
+		s.info.Unsubscribe = fmt.Sprintf("%s.%s", DefaultUnSubPrefix, clusterID)
+		s.info.Close = fmt.Sprintf("%s.%s", DefaultClosePrefix, clusterID)
+		s.info.AcksSubs = fmt.Sprintf("%s.%s", defaultAcksPrefix, clusterID)
 
 		if s.opts.Clustering.Clustered {
 			// If clustered, assign a random cluster node ID if not provided.