Announce node_announcemnet even without listen addresses

Even if we don't have any listen addresses, it's still useful to
broadcast a node_announcement to get our node_features out there.

Here we do this and also improve the timing of our
node_announcement updates to be less spammy.

diff --git a/src/main.rs b/src/main.rs
index 159fa5b777c4d70a317128c072f12f9ec6c20f63..0722ff5c58f21938c0a540b1dbccdf39ef5e9dc0 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -781,24 +781,29 @@ async fn start_ldk() {
        });
 
        // Regularly broadcast our node_announcement. This is only required (or possible) if we have
-       // some public channels, and is only useful if we have public listen address(es) to announce.
-       // In a production environment, this should occur only after the announcement of new channels
-       // to avoid churn in the global network graph.
+       // some public channels.
        let peer_man = Arc::clone(&peer_manager);
+       let chan_man = Arc::clone(&channel_manager);
        let network = args.network;
-       if !args.ldk_announced_listen_addr.is_empty() {
-               tokio::spawn(async move {
-                       let mut interval = tokio::time::interval(Duration::from_secs(60));
-                       loop {
-                               interval.tick().await;
+       tokio::spawn(async move {
+               // First wait a minute until we have some peers and maybe have opened a channel.
+               tokio::time::sleep(Duration::from_secs(60)).await;
+               // Then, update our announcement once an hour to keep it fresh but avoid unnecessary churn
+               // in the global gossip network.
+               let mut interval = tokio::time::interval(Duration::from_secs(3600));
+               loop {
+                       interval.tick().await;
+                       // Don't bother trying to announce if we don't have any public channls, though our
+                       // peers should drop such an announcement anyway.
+                       if chan_man.list_channels().iter().any(|chan| chan.is_public) {
                                peer_man.broadcast_node_announcement(
                                        [0; 3],
                                        args.ldk_announced_node_name,
                                        args.ldk_announced_listen_addr.clone(),
                                );
                        }
-               });
-       }
+               }
+       });
 
        // Start the CLI.
        cli::poll_for_user_input(