[fixed] jetstream unique server name requirement across domains (#2378)

* [fixed] jetstream unique server name requirement across domains

including domain in server info
adding check for cluster name in duplicate leaf node connection check

This does not address non unique domains in the same domain, say within
super cluster.

Signed-off-by: Matthias Hanel <mh@synadia.com>

server/server.go

@@ -79,6 +79,7 @@ type Info struct {
 	Nonce             string   `json:"nonce,omitempty"`
 	Cluster           string   `json:"cluster,omitempty"`
 	Dynamic           bool     `json:"cluster_dynamic,omitempty"`
+	Domain            string   `json:"domain,omitempty"`
 	ClientConnectURLs []string `json:"connect_urls,omitempty"`    // Contains URLs a client can connect to.
 	WSConnectURLs     []string `json:"ws_connect_urls,omitempty"` // Contains URLs a ws client can connect to.
 	LameDuckMode      bool     `json:"ldm,omitempty"`
@@ -250,7 +251,7 @@ type Server struct {
 	rnMu      sync.RWMutex
 	raftNodes map[string]RaftNode
 
-	// For mapping from a raft node name back to a server name and cluster.
+	// For mapping from a raft node name back to a server name and cluster. Node has to be in the same domain.
 	nodeToInfo sync.Map
 
 	// For out of resources to not log errors too fast.
@@ -331,6 +332,7 @@ func NewServer(opts *Options) (*Server, error) {
 		JetStream:    opts.JetStream,
 		Headers:      !opts.NoHeaderSupport,
 		Cluster:      opts.Cluster.Name,
+		Domain:       opts.JetStreamDomain,
 	}
 
 	if tlsReq && !info.TLSRequired {