refactor(hole-punch): don't explicitly connect to the relay

Making a reservation or opening a circuit will automatically establish a connection to the relay, we don't need to do this manually. Plus, the relay in the test setup has a statically configured external address, meaning it doesn't need to learn its external address via identify.

Pull-Request: libp2p#4746.

hole-punching-tests/src/main.rs

@@ -20,8 +20,6 @@
 
 use anyhow::{Context, Result};
 use futures::stream::StreamExt;
-use libp2p::swarm::dial_opts::DialOpts;
-use libp2p::swarm::ConnectionId;
 use libp2p::{
     core::multiaddr::{Multiaddr, Protocol},
     dcutr, identify, noise, ping, relay,
@@ -85,10 +83,6 @@ async fn main() -> Result<()> {
         .build();
 
     client_listen_on_transport(&mut swarm, transport).await?;
-    let relay_conn_id = client_connect_to_relay(&mut swarm, relay_addr.clone())
-        .await
-        .context("Failed to connect to relay")?;
-
     client_setup(&mut swarm, &mut redis, relay_addr.clone(), mode).await?;
 
     let mut hole_punched_peer_connection = None;
@@ -118,8 +112,6 @@ async fn main() -> Result<()> {
             ) => {
                 log::info!("Successfully hole-punched to {remote_peer_id}");
 
-                // Closing the connection to the relay will implicitly close the relayed connection to the other peer.
-                swarm.close_connection(relay_conn_id);
                 hole_punched_peer_connection = Some(connection_id);
             }
             (
@@ -150,19 +142,6 @@ async fn main() -> Result<()> {
             (SwarmEvent::OutgoingConnectionError { error, .. }, _) => {
                 anyhow::bail!(error)
             }
-            (
-                SwarmEvent::ConnectionClosed {
-                    connection_id,
-                    cause: Some(error),
-                    ..
-                },
-                _,
-            ) if connection_id == relay_conn_id => {
-                log::warn!("Connection to relay failed: {error}");
-
-                // TODO: Re-connecting is a bit of a hack, we should figure out why the connection sometimes fails.
-                client_setup(&mut swarm, &mut redis, relay_addr.clone(), mode).await?;
-            }
             _ => {}
         }
     }
@@ -194,40 +173,6 @@ where
     Ok(val)
 }
 
-async fn client_connect_to_relay(
-    swarm: &mut Swarm<Behaviour>,
-    relay_addr: Multiaddr,
-) -> Result<ConnectionId> {
-    let opts = DialOpts::from(relay_addr);
-    let relay_connection_id = opts.connection_id();
-
-    // Connect to the relay server.
-    swarm.dial(opts)?;
-
-    loop {
-        match swarm.next().await.unwrap() {
-            SwarmEvent::Behaviour(BehaviourEvent::Identify(identify::Event::Received {
-                info: identify::Info { observed_addr, .. },
-                ..
-            })) => {
-                log::info!("Relay told us our public address: {observed_addr}");
-                break;
-            }
-            SwarmEvent::ConnectionEstablished { connection_id, .. }
-                if connection_id == relay_connection_id =>
-            {
-                log::info!("Connected to the relay");
-            }
-            SwarmEvent::OutgoingConnectionError { error, .. } => {
-                anyhow::bail!(error)
-            }
-            _ => {}
-        }
-    }
-
-    Ok(relay_connection_id)
-}
-
 async fn client_listen_on_transport(
     swarm: &mut Swarm<Behaviour>,
     transport: TransportProtocol,