feat: Add DNS to SwarmBuilder

crates/node/gossip/Cargo.toml

@@ -40,7 +40,7 @@ libp2p-stream.workspace = true
 discv5 = { workspace = true, features = ["libp2p"] }
 openssl = { workspace = true, features = ["vendored"] }
 libp2p-identity = { workspace = true, features = ["secp256k1"] }
-libp2p = { workspace = true, features = ["macros", "tokio", "tcp", "noise", "gossipsub", "ping", "yamux", "identify"] }
+libp2p = { workspace = true, features = ["macros", "tokio", "tcp", "dns", "noise", "gossipsub", "ping", "yamux", "identify"] }
 ipnet = { workspace = true, features = ["serde"] }
 
 # Misc

crates/node/gossip/src/builder.rs

@@ -192,7 +192,8 @@ impl GossipDriverBuilder {
             .accept(sync_protocol_name)
             .map_err(|_| GossipDriverBuilderError::SyncReqRespAlreadyAccepted)?;
 
-        // Build the swarm.
+        // Build the swarm with DNS+TCP transport.
+        // Note: with_dns() must be called after with_tcp() to wrap TCP with DNS resolution.
         debug!(target: "gossip", "Building Swarm with Peer ID: {}", keypair.public().to_peer_id());
         let swarm = SwarmBuilder::with_existing_identity(keypair)
             .with_tokio()
@@ -205,6 +206,8 @@ impl GossipDriverBuilder {
                 YamuxConfig::default,
             )
             .map_err(|_| GossipDriverBuilderError::TcpError)?
+            .with_dns()
+            .map_err(|_| GossipDriverBuilderError::TcpError)?
             .with_behaviour(|_| behaviour)
             .map_err(|_| GossipDriverBuilderError::WithBehaviourError)?
             .with_swarm_config(|c| c.with_idle_connection_timeout(timeout))

crates/node/gossip/src/driver.rs

@@ -266,6 +266,7 @@ where
         }
 
         // Let the gate know we are dialing the address.
+        // Note: libp2p-dns will automatically resolve DNS multiaddrs at the transport layer.
         self.connection_gate.dialing(&addr);
 
         // Dial
@@ -409,6 +410,10 @@ where
             }
             SwarmEvent::OutgoingConnectionError { peer_id: _peer_id, error, .. } => {
                 debug!(target: "gossip", "Outgoing connection error: {:?}", error);
+                // Remove the peer from current_dials so it can be dialed again
+                if let Some(peer_id) = _peer_id {
+                    self.connection_gate.remove_dial(&peer_id);
+                }
                 kona_macros::inc!(
                     gauge,
                     crate::Metrics::GOSSIPSUB_CONNECTION,