feat(iroh-net): allow customizing republish delay for the pkarr publi…

…sher (#2637)

## Description

The pkarr dht publisher has two delays, the initial delay and the
republish delay. These were constants so far, but now are configurable
in the builder.

This allows us to set the delay to 0s in the dht_discovery_smoke test.

## Breaking Changes

None

## Notes & open questions

Will this fix the flakiness?

## Change checklist

- [x] Self-review.
- [x] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [x] All breaking changes documented.

Co-authored-by: Friedel Ziegelmayer <[email protected]>

iroh-cli/Cargo.toml

@@ -44,7 +44,7 @@ iroh = { version = "0.22.0", path = "../iroh", features = ["metrics"] }
 iroh-gossip = { version = "0.22.0", path = "../iroh-gossip" }
 iroh-metrics = { version = "0.22.0", path = "../iroh-metrics" }
 parking_lot = "0.12.1"
-pkarr = { version = "1.1.5", default-features = false }
+pkarr = { version = "2.0.0", default-features = false }
 portable-atomic = "1"
 postcard = "1.0.8"
 quic-rpc = { version = "0.11", features = ["flume-transport", "quinn-transport"] }

iroh-cli/src/commands/doctor.rs

@@ -1015,7 +1015,7 @@ fn bold<T: Display>(x: T) -> String {
 }
 
 fn to_z32(node_id: NodeId) -> String {
-    pkarr::PublicKey::try_from(*node_id.as_bytes())
+    pkarr::PublicKey::try_from(node_id.as_bytes())
         .unwrap()
         .to_z32()
 }

iroh-net/src/discovery/pkarr/dht.rs

@@ -73,6 +73,10 @@ struct Inner {
     ttl: u32,
     /// True to include the direct addresses in the DNS packet.
     include_direct_addresses: bool,
+    /// Initial delay before the first publish.
+    initial_publish_delay: Duration,
+    /// Republish delay for the DHT.
+    republish_delay: Duration,
 }
 
 /// Builder for PkarrNodeDiscovery.
@@ -86,6 +90,8 @@ pub struct Builder {
     pkarr_relay: Option<Url>,
     dht: bool,
     include_direct_addresses: bool,
+    initial_publish_delay: Duration,
+    republish_delay: Duration,
 }
 
 impl Default for Builder {
@@ -97,6 +103,8 @@ impl Default for Builder {
             pkarr_relay: None,
             dht: true,
             include_direct_addresses: false,
+            initial_publish_delay: INITIAL_PUBLISH_DELAY,
+            republish_delay: REPUBLISH_DELAY,
         }
     }
 }
@@ -146,6 +154,18 @@ impl Builder {
         self
     }
 
+    /// Set the initial delay before the first publish.
+    pub fn initial_publish_delay(mut self, initial_publish_delay: Duration) -> Self {
+        self.initial_publish_delay = initial_publish_delay;
+        self
+    }
+
+    /// Set the republish delay for the DHT.
+    pub fn republish_delay(mut self, republish_delay: Duration) -> Self {
+        self.republish_delay = republish_delay;
+        self
+    }
+
     /// Build the discovery mechanism.
     pub fn build(self) -> anyhow::Result<DhtDiscovery> {
         let pkarr = self
@@ -175,11 +195,13 @@ impl Builder {
         Ok(DhtDiscovery(Arc::new(Inner {
             pkarr,
             pkarr_relay,
-            secret_key: self.secret_key,
             ttl,
             relay_url,
             dht,
             include_direct_addresses,
+            secret_key: self.secret_key,
+            initial_publish_delay: self.initial_publish_delay,
+            republish_delay: self.republish_delay,
             task: Default::default(),
         })))
     }
@@ -199,7 +221,7 @@ impl DhtDiscovery {
             .to_z32();
         // initial delay. If the task gets aborted before this delay is over,
         // we have not published anything to the DHT yet.
-        tokio::time::sleep(INITIAL_PUBLISH_DELAY).await;
+        tokio::time::sleep(this.0.initial_publish_delay).await;
         loop {
             // publish to the DHT if enabled
             let dht_publish = async {
@@ -240,7 +262,7 @@ impl DhtDiscovery {
             };
             // do both at the same time
             tokio::join!(relay_publish, dht_publish);
-            tokio::time::sleep(REPUBLISH_DELAY).await;
+            tokio::time::sleep(this.0.republish_delay).await;
         }
     }
 
@@ -378,7 +400,7 @@ mod tests {
         let _ = tracing_subscriber::fmt::try_init();
         let ep = crate::Endpoint::builder().bind(0).await?;
         let secret = ep.secret_key().clone();
-        let testnet = mainline::dht::Testnet::new(5);
+        let testnet = mainline::dht::Testnet::new(2);
         let settings = pkarr::Settings {
             dht: DhtSettings {
                 bootstrap: Some(testnet.bootstrap.clone()),
@@ -389,6 +411,7 @@ mod tests {
         let client = PkarrClient::new(settings)?;
         let discovery = DhtDiscovery::builder()
             .secret_key(secret.clone())
+            .initial_publish_delay(Duration::ZERO)
             .client(client)
             .build()?;
         let relay_url: RelayUrl = Url::parse("https://example.com")?.into();