Add support for cli provided peers

src/builderhub/mod.rs

@@ -19,8 +19,15 @@ use openssl::{
     x509::X509,
 };
 use std::{
-    convert::Infallible, fmt::Debug, future::Future, io, net::SocketAddr, num::NonZero,
-    path::PathBuf, sync::Arc, time::Duration,
+    convert::Infallible,
+    fmt::Debug,
+    future::Future,
+    io,
+    net::SocketAddr,
+    num::NonZero,
+    path::{Path, PathBuf},
+    sync::Arc,
+    time::Duration,
 };
 use tokio::net::{lookup_host, ToSocketAddrs};
 
@@ -165,6 +172,30 @@ impl LocalPeerStore {
     }
 }
 
+impl LocalPeerStore {
+    /// Load peers from a JSON file and insert them into the store, keyed by their `name`.
+    ///
+    /// Used by dev mode (`--dev-peers <filepath>`) to seed the local peer store from a static
+    /// list instead of using BuilderHub.
+    pub fn load_from_file(&self, path: &Path) -> Result<(), LocalPeerStoreLoadError> {
+        let bytes = std::fs::read(path).map_err(LocalPeerStoreLoadError::Io)?;
+        let peers: Vec<Peer> =
+            serde_json::from_slice(&bytes).map_err(LocalPeerStoreLoadError::Parse)?;
+        for peer in peers {
+            self.builders.insert(peer.name.clone(), peer);
+        }
+        Ok(())
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum LocalPeerStoreLoadError {
+    #[error("failed to read dev peers file: {0}")]
+    Io(#[source] io::Error),
+    #[error("failed to parse dev peers file: {0}")]
+    Parse(#[source] serde_json::Error),
+}
+
 impl PeerStore for LocalPeerStore {
     type Error = Infallible;
 

src/cli.rs

@@ -238,6 +238,18 @@ pub struct OrderflowIngressArgs {
     #[clap(long, value_hint = ValueHint::Url, env = "BUILDERHUB_ENDPOINT", id = "BUILDERHUB_ENDPOINT")]
     pub builder_hub_url: Option<String>,
 
+    /// Path to a JSON file containing a static list of peers for development/testing.
+    /// When set, BuilderHub is not used and peers are loaded from this file (refreshed on the
+    /// regular peer update interval). Conflicts with `--builder-hub-url`.
+    #[clap(
+        long,
+        value_hint = ValueHint::FilePath,
+        env = "DEV_PEERS",
+        id = "DEV_PEERS",
+        conflicts_with = "BUILDERHUB_ENDPOINT"
+    )]
+    pub dev_peers: Option<PathBuf>,
+
     /// Enable Prometheus metrics.
     /// The metrics will be served at the given interface and port.
     #[arg(long, env = "METRICS_ADDR", id = "METRICS_ADDR")]
@@ -376,6 +388,7 @@ impl Default for OrderflowIngressArgs {
             builder_name: String::from("buildernet"),
             builder_region: Region::US,
             builder_hub_url: None,
+            dev_peers: None,
             flashbots_signer: None,
             max_txs_per_bundle: 100,
             enable_rate_limiting: false,

src/lib.rs

@@ -168,9 +168,18 @@ pub async fn run_with_listeners(
         task_executor
             .spawn_critical("run_update_peers", peer_updater.run(args.peer_update_interval_s));
     } else {
-        tracing::warn!("No BuilderHub URL provided, running with local peer store");
         let local_peer_store = LOCAL_PEER_STORE.clone();
 
+        if let Some(dev_peers_path) = args.dev_peers.as_ref() {
+            tracing::warn!(
+                path = %dev_peers_path.display(),
+                "Running in dev mode with static peers from file"
+            );
+            local_peer_store.load_from_file(dev_peers_path)?;
+        } else {
+            tracing::warn!("No BuilderHub URL provided, running with local peer store");
+        }
+
         let peer_store = local_peer_store.register(
             local_signer,
             Some(system_listener.local_addr().expect("bound").port()),