add broken discovery example. Discv5 starts but everything is not quite set up. Change the ConsensusNetworkInterface trait function to async so it works with p2p plus for the rpc setup you can add a feature to retrieve the requisite paths from a cached file.

client/src/client.rs

@@ -108,7 +108,7 @@ impl ClientBuilder {
         self
     }
 
-    pub fn build<DB: Database, N: ConsensusNetworkInterface>(self) -> Result<Client<DB, N>> {
+    pub async fn build<DB: Database, N: ConsensusNetworkInterface>(self) -> Result<Client<DB, N>> {
         let base_config = if let Some(network) = self.network {
             network.to_base_config()
         } else {
@@ -208,7 +208,7 @@ impl ClientBuilder {
             strict_checkpoint_age,
         };
 
-        Client::new(config)
+        Client::new(config).await
     }
 }
 
@@ -222,7 +222,7 @@ pub struct Client<DB: Database, N: ConsensusNetworkInterface> {
 }
 
 impl<DB: Database, N: ConsensusNetworkInterface> Client<DB, N> {
-    fn new(mut config: Config) -> Result<Self> {
+    async fn new(mut config: Config) -> Result<Self> {
         let db = DB::new(&config)?;
         if config.checkpoint.is_none() {
             let checkpoint = db.load_checkpoint()?;
@@ -230,7 +230,7 @@ impl<DB: Database, N: ConsensusNetworkInterface> Client<DB, N> {
         }
 
         let config = Arc::new(config);
-        let node = Node::<N>::new(config.clone())?;
+        let node = Node::<N>::new(config.clone()).await?;
         let node = Arc::new(RwLock::new(node));
 
         #[cfg(not(target_arch = "wasm32"))]
@@ -344,7 +344,7 @@ impl<DB: Database, N: ConsensusNetworkInterface> Client<DB, N> {
             // We fail fast here since the node is unrecoverable at this point
             let config = self.node.read().await.config.clone();
             let consensus =
-                ConsensusClient::new(&config.consensus_rpc, checkpoint.as_bytes(), config.clone())?;
+                ConsensusClient::new(&config.consensus_rpc, checkpoint.as_bytes(), config.clone()).await?;
             self.node.write().await.consensus = consensus;
             self.node.write().await.sync().await?;
 
@@ -385,7 +385,7 @@ impl<DB: Database, N: ConsensusNetworkInterface> Client<DB, N> {
         // We fail fast here since the node is unrecoverable at this point
         let config = self.node.read().await.config.clone();
         let consensus =
-            ConsensusClient::new(&config.consensus_rpc, checkpoint.as_bytes(), config.clone())?;
+            ConsensusClient::new(&config.consensus_rpc, checkpoint.as_bytes(), config.clone()).await?;
         self.node.write().await.consensus = consensus;
         self.node.write().await.sync().await?;
         Ok(())

client/src/node.rs

@@ -33,12 +33,13 @@ pub struct Node<N: ConsensusNetworkInterface> {
 }
 
 impl<N: ConsensusNetworkInterface> Node<N> {
-    pub fn new(config: Arc<Config>) -> Result<Self, NodeError> {
+    pub async fn new(config: Arc<Config>) -> Result<Self, NodeError> {
         let consensus_rpc = &config.consensus_rpc;
         let checkpoint_hash = &config.checkpoint.as_ref().unwrap();
         let execution_rpc = &config.execution_rpc;
 
         let consensus = ConsensusClient::new(consensus_rpc, checkpoint_hash, config.clone())
+            .await
             .map_err(NodeError::ConsensusClientCreationError)?;
         let execution = Arc::new(
             ExecutionClient::new(execution_rpc).map_err(NodeError::ExecutionClientCreationError)?,

consensus/src/consensus.rs

@@ -54,12 +54,12 @@ struct LightClientStore {
 }
 
 impl<N: ConsensusNetworkInterface> ConsensusClient<N> {
-    pub fn new(
+    pub async fn new(
         rpc: &str,
         checkpoint_block_root: &[u8],
         config: Arc<Config>,
     ) -> Result<ConsensusClient<N>> {
-        let network_interface = N::new(rpc);
+        let network_interface = N::new(rpc).await;
 
         Ok(ConsensusClient {
             network_interface,

consensus/src/p2p/discovery/mod.rs

@@ -14,14 +14,16 @@ use futures::{
     stream::FuturesUnordered,
     StreamExt,
 };
-use std::future::Future;
-use std::pin::Pin;
-use std::net::SocketAddr;
-use std::time::Instant;
-use std::collections::HashMap;
-use std::task::{Context, Poll};
+use std::{
+    future::Future,
+    pin::Pin,
+    net::SocketAddr,
+    time::Instant,
+    collections::HashMap,
+    task::{Context, Poll},
+    sync::{Arc, Mutex},
+};
 use log::{debug, error};
-use std::sync::{Arc, Mutex};
 
 use super::config::Config as ConsensusConfig;
 mod enr;
@@ -42,6 +44,7 @@ enum EventStream {
 
 type DiscResult = Result<Vec<Enr>, QueryError>;
 
+#[derive(Debug)]
 pub enum DiscoveryError {
     Discv5Error(Discv5Error),
     UnexpectedError(String),
@@ -79,12 +82,14 @@ impl Discovery {
         local_key: &Keypair,
         config: ConsensusConfig,
     ) -> Result<Self, DiscoveryError> {
+        // convert the keypair to an ENR key
         let enr_key = key_from_libp2p(local_key)?;
         let local_enr = build_enr(&enr_key, &config);
         let listen_socket = SocketAddr::new(config.listen_addr, config.discovery_port);
 
         let mut discv5 = Discv5::new(local_enr.clone(), enr_key, config.discv5_config)?;
 
+        // Add bootnodes to routing table
         for boot_node_enr in config.boot_nodes_enr.clone() {
             debug!("Adding boot node: {:?}", boot_node_enr);
             let repr = boot_node_enr.to_string();
@@ -92,6 +97,8 @@ impl Discovery {
                 error!("Failed to add boot node: {:?}, {:?}", repr, e);
             });
         }
+
+        // Start the discv5 service and obtain an event stream
         let event_stream = if !config.disable_discovery {
             discv5
                 .start(listen_socket)

consensus/src/p2p/p2p_network_interface.rs

@@ -1,7 +1,11 @@
 use eyre::Result;
 use crate::types::{BeaconBlock, Bootstrap, FinalityUpdate, OptimisticUpdate, Update};
 use async_trait::async_trait;
-use libp2p::swarm::NetworkBehaviour;
+use libp2p::{
+    swarm::NetworkBehaviour,
+    identity::Keypair,
+};
+
 
 use crate::p2p::discovery::Discovery;
 use crate::rpc::ConsensusNetworkInterface;
@@ -13,8 +17,12 @@ pub struct P2pNetworkInterface {
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 impl ConsensusNetworkInterface for P2pNetworkInterface {
-    fn new(_path: &str) -> Self {
-        unimplemented!()
+    // TODO: Really implement this function
+    async fn new(_path: &str) -> Self {
+        let local_key = Keypair::generate_secp256k1();
+        let config = super::config::Config::default();
+        let discovery = Discovery::new(&local_key, config).await.unwrap();
+        Self { discovery }
     }
 
     async fn get_bootstrap(&self, _block_root: &'_ [u8]) -> Result<Bootstrap> {

consensus/src/rpc/mock_rpc.rs

@@ -12,7 +12,7 @@ pub struct MockRpc {
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 impl ConsensusNetworkInterface for MockRpc {
-    fn new(path: &str) -> Self {
+    async fn new(path: &str) -> Self {
         MockRpc {
             testdata: PathBuf::from(path),
         }

consensus/src/rpc/mod.rs

@@ -10,7 +10,7 @@ use crate::types::{BeaconBlock, Bootstrap, FinalityUpdate, OptimisticUpdate, Upd
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 pub trait ConsensusNetworkInterface: Sync + Send + 'static {
-    fn new(path: &str) -> Self;
+    async fn new(path: &str) -> Self;
     async fn get_bootstrap(&self, block_root: &'_ [u8]) -> Result<Bootstrap>;
     async fn get_updates(&self, period: u64, count: u8) -> Result<Vec<Update>>;
     async fn get_finality_update(&self) -> Result<FinalityUpdate>;

consensus/src/rpc/nimbus_rpc.rs

@@ -15,7 +15,7 @@ pub struct NimbusRpc {
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 impl ConsensusNetworkInterface for NimbusRpc {
-    fn new(rpc: &str) -> Self {
+    async fn new(rpc: &str) -> Self {
         NimbusRpc {
             rpc: rpc.to_string(),
         }

examples/basic.rs

@@ -4,6 +4,7 @@ use env_logger::Env;
 use ethers::{types::Address, utils};
 use eyre::Result;
 use helios::{config::networks::Network, prelude::*};
+use consensus::rpc::nimbus_rpc::NimbusRpc;
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -15,13 +16,14 @@ async fn main() -> Result<()> {
     let consensus_rpc = "https://www.lightclientdata.org";
     log::info!("Using consensus RPC URL: {}", consensus_rpc);
 
-    let mut client: Client<FileDB> = ClientBuilder::new()
+    let mut client: Client<FileDB, NimbusRpc> = ClientBuilder::new()
         .network(Network::MAINNET)
         .consensus_rpc(consensus_rpc)
         .execution_rpc(untrusted_rpc_url)
         .load_external_fallback()
         .data_dir(PathBuf::from("/tmp/helios"))
-        .build()?;
+        .build()
+        .await?;
 
     log::info!(
         "Built client on network \"{}\" with external checkpoint fallbacks",

examples/client.rs

@@ -1,5 +1,6 @@
 use std::path::PathBuf;
 
+use consensus::rpc::nimbus_rpc::NimbusRpc;
 use eyre::Result;
 
 use helios::prelude::*;
@@ -35,7 +36,10 @@ async fn main() -> Result<()> {
     builder = builder.load_external_fallback();
 
     // Build the client
-    let _client: Client<FileDB> = builder.build().unwrap();
+    let _client: Client<FileDB, NimbusRpc> = builder
+        .build()
+        .await
+        .unwrap();
     println!("Constructed client!");
 
     Ok(())

examples/discovery.rs

@@ -0,0 +1,48 @@
+use std::{path::PathBuf, str::FromStr};
+
+use env_logger::Env;
+use ethers::{types::Address, utils};
+use eyre::Result;
+use helios::{config::networks::Network, prelude::*};
+
+use consensus::p2p::P2pNetworkInterface;
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    env_logger::Builder::from_env(Env::default().default_filter_or("info")).init();
+
+    let untrusted_rpc_url = "https://eth-mainnet.g.alchemy.com/v2/nObEU8Wh4FIT-X_UDFpK9oVGiTHzznML";
+    log::info!("Using untrusted RPC URL [REDACTED]");
+
+    let consensus_rpc = "https://www.lightclientdata.org";
+    log::info!("Using consensus RPC URL: {}", consensus_rpc);
+
+    let mut client: Client<FileDB, P2pNetworkInterface> = ClientBuilder::new()
+        .network(Network::MAINNET)
+        .consensus_rpc(consensus_rpc)
+        .execution_rpc(untrusted_rpc_url)
+        .load_external_fallback()
+        .data_dir(PathBuf::from("/tmp/helios"))
+        .build()
+        .await?;
+
+    log::info!(
+        "Built client on network \"{}\" with external checkpoint fallbacks",
+        Network::MAINNET
+    );
+
+    client.start().await?;
+
+    let head_block_num = client.get_block_number().await?;
+    let addr = Address::from_str("0x00000000219ab540356cBB839Cbe05303d7705Fa")?;
+    let block = BlockTag::Latest;
+    let balance = client.get_balance(&addr, block).await?;
+
+    log::info!("synced up to block: {}", head_block_num);
+    log::info!(
+        "balance of deposit contract: {}",
+        utils::format_ether(balance)
+    );
+
+    Ok(())
+}