chore: add network example (paradigmxyz#3753)

Cargo.toml

@@ -101,6 +101,7 @@ reth-revm = { path = "./crates/revm" }
 reth-payload-builder = { path = "./crates/payload/builder" }
 reth-transaction-pool = { path = "./crates/transaction-pool" }
 reth-tasks = { path = "./crates/tasks" }
+reth-network = { path = "./crates/net/network" }
 reth-network-api = { path = "./crates/net/network-api" }
 
 ## eth

crates/net/network/src/config.rs

@@ -11,7 +11,9 @@ use reth_discv4::{Discv4Config, Discv4ConfigBuilder, DEFAULT_DISCOVERY_PORT};
 use reth_dns_discovery::DnsDiscoveryConfig;
 use reth_ecies::util::pk2id;
 use reth_eth_wire::{HelloMessage, Status};
-use reth_primitives::{ChainSpec, ForkFilter, Head, NodeRecord, PeerId, MAINNET};
+use reth_primitives::{
+    mainnet_nodes, sepolia_nodes, ChainSpec, ForkFilter, Head, NodeRecord, PeerId, MAINNET,
+};
 use reth_provider::{BlockReader, HeaderProvider};
 use reth_tasks::{TaskSpawner, TokioTaskExecutor};
 use secp256k1::SECP256K1;
@@ -31,6 +33,9 @@ pub fn rng_secret_key() -> SecretKey {
 /// All network related initialization settings.
 pub struct NetworkConfig<C> {
     /// The client type that can interact with the chain.
+    ///
+    /// This type is used to fetch the block number after we established a session and received the
+    /// [Status] block hash.
     pub client: C,
     /// The node's secret key, from which the node's identity is derived.
     pub secret_key: SecretKey,
@@ -278,6 +283,16 @@ impl NetworkConfigBuilder {
         self
     }
 
+    /// Convenience function for setting [Self::boot_nodes] to the mainnet boot nodes.
+    pub fn mainnet_boot_nodes(self) -> Self {
+        self.boot_nodes(mainnet_nodes())
+    }
+
+    /// Convenience function for setting [Self::boot_nodes] to the sepolia boot nodes.
+    pub fn sepolia_boot_nodes(self) -> Self {
+        self.boot_nodes(sepolia_nodes())
+    }
+
     /// Sets the boot nodes.
     pub fn boot_nodes(mut self, nodes: impl IntoIterator<Item = NodeRecord>) -> Self {
         self.boot_nodes = nodes.into_iter().collect();
@@ -330,6 +345,10 @@ impl NetworkConfigBuilder {
 
     /// Consumes the type and creates the actual [`NetworkConfig`]
     /// for the given client type that can interact with the chain.
+    ///
+    /// The given client is to be used for interacting with the chain, for example fetching the
+    /// corresponding block for a given block hash we receive from a peer in the status message when
+    /// establishing a connection.
     pub fn build<C>(self, client: C) -> NetworkConfig<C> {
         let peer_id = self.get_peer_id();
         let Self {

crates/net/network/src/state.rs

@@ -51,6 +51,9 @@ pub struct NetworkState<C> {
     /// Buffered messages until polled.
     queued_messages: VecDeque<StateAction>,
     /// The client type that can interact with the chain.
+    ///
+    /// This type is used to fetch the block number after we established a session and received the
+    /// [Status] block hash.
     client: C,
     /// Network discovery.
     discovery: Discovery,

examples/Cargo.toml

@@ -6,25 +6,26 @@ edition.workspace = true
 license.workspace = true
 
 [dev-dependencies]
-reth-primitives = { workspace = true }
+reth-primitives.workspace = true
 
-reth-db = { workspace = true }
-reth-provider = { workspace = true }
+reth-db.workspace = true
+reth-provider.workspace = true
 
-reth-rpc-builder = { workspace = true }
-reth-rpc-types = { workspace = true }
+reth-rpc-builder.workspace = true
+reth-rpc-types.workspace = true
 
-reth-revm = { workspace = true }
-reth-blockchain-tree = { workspace = true }
-reth-beacon-consensus = { workspace = true }
-reth-network-api = { workspace = true }
-reth-transaction-pool = { workspace = true }
-reth-tasks = { workspace = true }
+reth-revm.workspace = true
+reth-blockchain-tree.workspace = true
+reth-beacon-consensus.workspace = true
+reth-network-api.workspace = true
+reth-network.workspace = true
+reth-transaction-pool.workspace = true
+reth-tasks.workspace = true
 
 
 eyre = "0.6.8"
-futures = "0.3.0"
-tokio = { workspace = true }
+futures.workspace = true
+tokio.workspace = true
 
 [[example]]
 name = "rpc-db"
@@ -33,3 +34,7 @@ path = "rpc-db.rs"
 [[example]]
 name = "db-access"
 path = "db-access.rs"
+
+[[example]]
+name = "network"
+path = "network.rs"

examples/network.rs

@@ -0,0 +1,41 @@
+//! Example of how to use the network as a standalone component
+//!
+//! Run with
+//!
+//! ```not_rust
+//! cargo run --example network
+//! ```
+
+use futures::StreamExt;
+use reth_network::{config::rng_secret_key, NetworkConfig, NetworkManager};
+use reth_provider::test_utils::NoopProvider;
+
+#[tokio::main]
+async fn main() -> eyre::Result<()> {
+    // This block provider implementation is used for testing purposes.
+    let client = NoopProvider::default();
+
+    // The key that's used for encrypting sessions and to identify our node.
+    let local_key = rng_secret_key();
+
+    // Configure the network
+    let config =
+        NetworkConfig::<NoopProvider>::builder(local_key).mainnet_boot_nodes().build(client);
+
+    // create the network instance
+    let network = NetworkManager::new(config).await?;
+
+    // get a handle to the network to interact with it
+    let handle = network.handle().clone();
+
+    // spawn the network
+    tokio::task::spawn(network);
+
+    // interact with the network
+    let mut events = handle.event_listener();
+    while let Some(event) = events.next().await {
+        println!("Received event: {:?}", event);
+    }
+
+    Ok(())
+}