fix: use default (google) dns servers if system resolv.conf is invalid (

#447)

* fix: use default (google) dns servers if system resolv.conf is invalid

If the system dns conf is missing nameservers, dns queries will never be resolved. Currently, hickory-dns doesn't error in this case so we handle it manually until the fix is released. This happens on osx if wifi is disabled when you start c1 and is never able to resolve itself without this change.

* fix: new clippy lint

p2p/Cargo.toml

@@ -21,6 +21,9 @@ ceramic-store.workspace = true
 cid.workspace = true
 futures-util.workspace = true
 futures.workspace = true
+# temporary to address lack of error for invalid resolv.conf (missing nameservers)
+# and libp2p not exposing enough types to actually build a dns resolver
+hickory-resolver = { version = "0.24.1", default-features = false, features = ["system-config"] }
 iroh-bitswap.workspace = true
 iroh-rpc-client.workspace = true
 iroh-rpc-types.workspace = true

p2p/src/swarm.rs

@@ -1,12 +1,33 @@
 use anyhow::Result;
 use ceramic_core::{EventId, Interest};
-use libp2p::{noise, relay, tcp, tls, yamux, Swarm, SwarmBuilder};
+use libp2p::{dns, noise, relay, tcp, tls, yamux, Swarm, SwarmBuilder};
 use libp2p_identity::Keypair;
 use recon::{libp2p::Recon, Sha256a};
 use std::sync::Arc;
 
 use crate::{behaviour::NodeBehaviour, Libp2pConfig, Metrics};
 
+fn get_dns_config() -> (dns::ResolverConfig, dns::ResolverOpts) {
+    match hickory_resolver::system_conf::read_system_conf() {
+        Ok((conf, opts)) => {
+            // Won't be necessary if https://github.com/hickory-dns/hickory-dns/pull/2327 is merged/incoporated into libp2p
+            let conf = if conf.name_servers().is_empty() {
+                tracing::warn!(
+                    "No nameservers found in system DNS configuration. Using Google DNS servers."
+                );
+                dns::ResolverConfig::default()
+            } else {
+                conf
+            };
+            (conf, opts)
+        }
+        Err(e) => {
+            tracing::warn!(err=%e, "Failed to load system DNS configuration. Switching to Google DNS servers. This can only be retried on server restart.");
+            (dns::ResolverConfig::default(), dns::ResolverOpts::default())
+        }
+    }
+}
+
 pub(crate) async fn build_swarm<I, M, S>(
     config: &Libp2pConfig,
     keypair: Keypair,
@@ -19,6 +40,7 @@ where
     M: Recon<Key = EventId, Hash = Sha256a>,
     S: iroh_bitswap::Store,
 {
+    let (dns_conf, dns_opts) = get_dns_config();
     let builder = SwarmBuilder::with_existing_identity(keypair)
         .with_tokio()
         .with_tcp(
@@ -29,7 +51,7 @@ where
             yamux::Config::default,
         )?
         .with_quic()
-        .with_dns()?
+        .with_dns_config(dns_conf, dns_opts)
         .with_websocket(
             (tls::Config::new, noise::Config::new),
             yamux::Config::default,

store/src/sql/access/event.rs

@@ -145,7 +145,7 @@ impl CeramicOneEvent {
         // Fetch add happens with an open transaction (on one writer for the db) so we're guaranteed to get a unique value
         sqlx::query(EventQuery::mark_ready_to_deliver())
             .bind(Self::next_deliverable())
-            .bind(&key.to_bytes())
+            .bind(key.to_bytes())
             .execute(&mut **conn.inner())
             .await?;