discovery/mdns: add netconfig change watcher
Watch netconfig change to make mdns reattach to new network interfaces
Change-Id: Id0f704de05e3a582d1e469329152b9bd6055558d
diff --git a/lib/discovery/plugins/mdns/mdns.go b/lib/discovery/plugins/mdns/mdns.go
index 08e9aa8..0c72e0d 100644
--- a/lib/discovery/plugins/mdns/mdns.go
+++ b/lib/discovery/plugins/mdns/mdns.go
@@ -30,6 +30,7 @@
"v.io/v23/context"
"v.io/v23/discovery"
+ "v.io/x/lib/netconfig"
idiscovery "v.io/x/ref/lib/discovery"
)
@@ -64,6 +65,10 @@
)
type plugin struct {
+ ctx *context.T
+ closed chan struct{}
+ wg sync.WaitGroup
+
mdns *mdns.MDNS
adStopper *idiscovery.Trigger
@@ -160,7 +165,32 @@
return nil
}
-func (p *plugin) Close() {}
+func (p *plugin) Close() {
+ close(p.closed)
+ p.wg.Wait()
+}
+
+func (p *plugin) watchNetConfig() {
+ defer p.wg.Done()
+
+ // Watch the network configuration so that we can make MDNS reattach to
+ // interfaces when the network changes.
+ for {
+ ch, err := netconfig.NotifyChange()
+ if err != nil {
+ p.ctx.Error(err)
+ return
+ }
+ select {
+ case <-ch:
+ if _, err := p.mdns.ScanInterfaces(); err != nil {
+ p.ctx.Error(err)
+ }
+ case <-p.closed:
+ return
+ }
+ }
+}
func (p *plugin) subscribeToService(serviceName string) {
p.subscriptionMu.Lock()
@@ -394,7 +424,7 @@
return newWithLoopback(ctx, host, 0, false)
}
-func newWithLoopback(_ *context.T, host string, port int, loopback bool) (idiscovery.Plugin, error) {
+func newWithLoopback(ctx *context.T, host string, port int, loopback bool) (idiscovery.Plugin, error) {
switch {
case len(host) == 0:
// go-mdns-sd doesn't answer when the host name is not set.
@@ -422,6 +452,8 @@
}
}
p := plugin{
+ ctx: ctx,
+ closed: make(chan struct{}),
mdns: m,
adStopper: idiscovery.NewTrigger(),
// TODO(jhahn): Figure out a good subscription refresh time.
@@ -433,5 +465,7 @@
} else {
p.subscriptionWaitTime = 50 * time.Millisecond
}
+ p.wg.Add(1)
+ go p.watchNetConfig()
return &p, nil
}
