mounttablelib: change neighborhood to try a more unique name if the
original name results in a collision.
Also, semantic change. Any empty host name used to be replaced by MDNS
to a unique name. Now an empty host naem means anonymous.
Change-Id: I44791fbd5eb6235ac074a2596addf89c89ba7619
diff --git a/services/mounttable/mounttablelib/neighborhood.go b/services/mounttable/mounttablelib/neighborhood.go
index 75488c2..20997cf 100644
--- a/services/mounttable/mounttablelib/neighborhood.go
+++ b/services/mounttable/mounttablelib/neighborhood.go
@@ -39,10 +39,6 @@
const addressPrefix = "address:"
-// AnonymousNeighbor is the neighborhood host name to use if you want to be a client of the neighborhood namespace
-// without appearing in it.
-const AnonymousNeighbor = "_"
-
// neighborhood defines a set of machines on the same multicast media.
type neighborhood struct {
mdns *mdns.MDNS
@@ -108,20 +104,30 @@
}
// Start up MDNS, subscribe to the vanadium service, and add us as a vanadium service provider.
- mdns, err := mdns.NewMDNS(host, "", "", loopback, false)
+ m, err := mdns.NewMDNS(host, "", "", loopback, false)
if err != nil {
- logger.Global().Errorf("mdns startup failed: %s", err)
- return nil, err
+ // The name may not have been unique. Try one more time with a unique
+ // name. NewMDNS will replace the "()" with "(hardware mac address)".
+ if len(host) > 0 {
+ m, err = mdns.NewMDNS(host+"()", "", "", loopback, false)
+ }
+ if err != nil {
+ logger.Global().Errorf("mdns startup failed: %s", err)
+ return nil, err
+ }
}
logger.Global().VI(2).Infof("listening for service vanadium on port %d", port)
- mdns.SubscribeToService("vanadium")
- if host != AnonymousNeighbor {
- mdns.AddService("vanadium", "", port, txt...)
+ m.SubscribeToService("vanadium")
+ if len(host) > 0 {
+ m.AddService("vanadium", "", port, txt...)
}
+
+ // A small sleep to allow the world to learn about us and vice versa. Not
+ // necessary but helpful.
time.Sleep(50 * time.Millisecond)
nh := &neighborhood{
- mdns: mdns,
+ mdns: m,
}
// Watch the network configuration so that we can make MDNS reattach to
