feat: initial bitcoind sync client support

Adds:
- Sync client configuration with RPC (default) and REST variants
- Extend the ChainSource::Bitcoind configuration options
- Preliminary implementation for BitcoindSyncClient in RPC mode

Author: enigbe

Cargo.toml

@@ -35,7 +35,7 @@ lightning-net-tokio = { version = "0.1.0" }
 lightning-persister = { version = "0.1.0" }
 lightning-background-processor = { version = "0.1.0", features = ["futures"] }
 lightning-rapid-gossip-sync = { version = "0.1.0" }
-lightning-block-sync = { version = "0.1.0", features = ["rpc-client", "tokio"] }
+lightning-block-sync = { version = "0.1.0", features = ["rpc-client", "rest-client", "tokio"] }
 lightning-transaction-sync = { version = "0.1.0", features = ["esplora-async-https", "time", "electrum"] }
 lightning-liquidity = { version = "0.1.0", features = ["std"] }
 

bindings/ldk_node.udl

@@ -34,6 +34,12 @@ dictionary ElectrumSyncConfig {
 	BackgroundSyncConfig? background_sync_config;
 };
 
+[Enum]
+interface BitcoindSyncClientConfig {
+	Rpc();
+	Rest(string rest_host, u16 rest_port);
+};
+
 dictionary LSPS2ServiceConfig {
 	string? require_token;
 	boolean advertise_service;
@@ -77,7 +83,7 @@ interface Builder {
 	void set_entropy_bip39_mnemonic(Mnemonic mnemonic, string? passphrase);
 	void set_chain_source_esplora(string server_url, EsploraSyncConfig? config);
 	void set_chain_source_electrum(string server_url, ElectrumSyncConfig? config);
-	void set_chain_source_bitcoind_rpc(string rpc_host, u16 rpc_port, string rpc_user, string rpc_password);
+	void set_chain_source_bitcoind(string rpc_host, u16 rpc_port, string rpc_user, string rpc_password, BitcoindSyncClientConfig? sync_client_config);
 	void set_gossip_source_p2p();
 	void set_gossip_source_rgs(string rgs_server_url);
 	void set_liquidity_source_lsps1(PublicKey node_id, SocketAddress address, string? token);

src/builder.rs

@@ -7,8 +7,9 @@
 
 use crate::chain::{ChainSource, DEFAULT_ESPLORA_SERVER_URL};
 use crate::config::{
-	default_user_config, may_announce_channel, AnnounceError, Config, ElectrumSyncConfig,
-	EsploraSyncConfig, DEFAULT_LOG_FILENAME, DEFAULT_LOG_LEVEL, WALLET_KEYS_SEED_LEN,
+	default_user_config, may_announce_channel, AnnounceError, BitcoindSyncClientConfig, Config,
+	ElectrumSyncConfig, EsploraSyncConfig, DEFAULT_LOG_FILENAME, DEFAULT_LOG_LEVEL,
+	WALLET_KEYS_SEED_LEN,
 };
 
 use crate::connection::ConnectionManager;
@@ -82,9 +83,21 @@ const LSPS_HARDENED_CHILD_INDEX: u32 = 577;
 
 #[derive(Debug, Clone)]
 enum ChainDataSourceConfig {
-	Esplora { server_url: String, sync_config: Option<EsploraSyncConfig> },
-	Electrum { server_url: String, sync_config: Option<ElectrumSyncConfig> },
-	BitcoindRpc { rpc_host: String, rpc_port: u16, rpc_user: String, rpc_password: String },
+	Esplora {
+		server_url: String,
+		sync_config: Option<EsploraSyncConfig>,
+	},
+	Electrum {
+		server_url: String,
+		sync_config: Option<ElectrumSyncConfig>,
+	},
+	Bitcoind {
+		rpc_host: String,
+		rpc_port: u16,
+		rpc_user: String,
+		rpc_password: String,
+		sync_client_config: BitcoindSyncClientConfig,
+	},
 }
 
 #[derive(Debug, Clone)]
@@ -297,13 +310,26 @@ impl NodeBuilder {
 		self
 	}
 
-	/// Configures the [`Node`] instance to source its chain data from the given Bitcoin Core RPC
+	/// Configures the [`Node`] instance to synchronize its chain data from the given Bitcoin Core RPC
 	/// endpoint.
-	pub fn set_chain_source_bitcoind_rpc(
+	///
+	/// This method configures an RPC connection for essential operations, with options for
+	/// synchronization via either RPC (default) or REST.
+	///
+	/// # Parameters:
+	/// * `rpc_host`, `rpc_port`, `rpc_user`, `rpc_password` - Required parameters for the Bitcoin Core RPC connection
+	/// * `sync_client_config` - Optional synchronization client configuration; defaults to using RPC for sync
+	pub fn set_chain_source_bitcoind(
 		&mut self, rpc_host: String, rpc_port: u16, rpc_user: String, rpc_password: String,
+		sync_client_config: Option<BitcoindSyncClientConfig>,
 	) -> &mut Self {
-		self.chain_data_source_config =
-			Some(ChainDataSourceConfig::BitcoindRpc { rpc_host, rpc_port, rpc_user, rpc_password });
+		self.chain_data_source_config = Some(ChainDataSourceConfig::Bitcoind {
+			rpc_host,
+			rpc_port,
+			rpc_user,
+			rpc_password,
+			sync_client_config: sync_client_config.unwrap_or(BitcoindSyncClientConfig::Rpc),
+		});
 		self
 	}
 
@@ -716,14 +742,16 @@ impl ArcedNodeBuilder {
 
 	/// Configures the [`Node`] instance to source its chain data from the given Bitcoin Core RPC
 	/// endpoint.
-	pub fn set_chain_source_bitcoind_rpc(
+	pub fn set_chain_source_bitcoind(
 		&self, rpc_host: String, rpc_port: u16, rpc_user: String, rpc_password: String,
+		sync_client_config: Option<BitcoindSyncClientConfig>,
 	) {
-		self.inner.write().unwrap().set_chain_source_bitcoind_rpc(
+		self.inner.write().unwrap().set_chain_source_bitcoind(
 			rpc_host,
 			rpc_port,
 			rpc_user,
 			rpc_password,
+			sync_client_config,
 		);
 	}
 
@@ -1061,21 +1089,26 @@ fn build_with_store_internal(
 				Arc::clone(&node_metrics),
 			))
 		},
-		Some(ChainDataSourceConfig::BitcoindRpc { rpc_host, rpc_port, rpc_user, rpc_password }) => {
-			Arc::new(ChainSource::new_bitcoind_rpc(
-				rpc_host.clone(),
-				*rpc_port,
-				rpc_user.clone(),
-				rpc_password.clone(),
-				Arc::clone(&wallet),
-				Arc::clone(&fee_estimator),
-				Arc::clone(&tx_broadcaster),
-				Arc::clone(&kv_store),
-				Arc::clone(&config),
-				Arc::clone(&logger),
-				Arc::clone(&node_metrics),
-			))
-		},
+		Some(ChainDataSourceConfig::Bitcoind {
+			rpc_host,
+			rpc_port,
+			rpc_user,
+			rpc_password,
+			sync_client_config,
+		}) => Arc::new(ChainSource::new_bitcoind(
+			rpc_host.clone(),
+			*rpc_port,
+			rpc_user.clone(),
+			rpc_password.clone(),
+			Arc::clone(&wallet),
+			Arc::clone(&fee_estimator),
+			Arc::clone(&tx_broadcaster),
+			Arc::clone(&kv_store),
+			Arc::clone(&config),
+			sync_client_config.clone(),
+			Arc::clone(&logger),
+			Arc::clone(&node_metrics),
+		)),
 		None => {
 			// Default to Esplora client.
 			let server_url = DEFAULT_ESPLORA_SERVER_URL.to_string();

src/chain/bitcoind_rpc.rs

@@ -13,9 +13,7 @@ use lightning_block_sync::http::HttpEndpoint;
 use lightning_block_sync::http::JsonResponse;
 use lightning_block_sync::poll::ValidatedBlockHeader;
 use lightning_block_sync::rpc::{RpcClient, RpcError};
-use lightning_block_sync::{
-	AsyncBlockSourceResult, BlockData, BlockHeaderData, BlockSource, Cache,
-};
+use lightning_block_sync::Cache;
 
 use serde::Serialize;
 
@@ -36,9 +34,8 @@ pub struct BitcoindRpcClient {
 
 impl BitcoindRpcClient {
 	pub(crate) fn new(host: String, port: u16, rpc_user: String, rpc_password: String) -> Self {
-		let http_endpoint = HttpEndpoint::for_host(host.clone()).with_port(port);
-		let rpc_credentials =
-			BASE64_STANDARD.encode(format!("{}:{}", rpc_user.clone(), rpc_password.clone()));
+		let http_endpoint = endpoint(host, port);
+		let rpc_credentials = rpc_credentials(rpc_user, rpc_password);
 
 		let rpc_client = Arc::new(RpcClient::new(&rpc_credentials, http_endpoint));
 
@@ -254,22 +251,12 @@ impl BitcoindRpcClient {
 	}
 }
 
-impl BlockSource for BitcoindRpcClient {
-	fn get_header<'a>(
-		&'a self, header_hash: &'a BlockHash, height_hint: Option<u32>,
-	) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
-		Box::pin(async move { self.rpc_client.get_header(header_hash, height_hint).await })
-	}
-
-	fn get_block<'a>(
-		&'a self, header_hash: &'a BlockHash,
-	) -> AsyncBlockSourceResult<'a, BlockData> {
-		Box::pin(async move { self.rpc_client.get_block(header_hash).await })
-	}
+pub(crate) fn rpc_credentials(rpc_user: String, rpc_password: String) -> String {
+	BASE64_STANDARD.encode(format!("{}:{}", rpc_user, rpc_password))
+}
 
-	fn get_best_block(&self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
-		Box::pin(async move { self.rpc_client.get_best_block().await })
-	}
+pub(crate) fn endpoint(host: String, port: u16) -> HttpEndpoint {
+	HttpEndpoint::for_host(host.clone()).with_port(port)
 }
 
 pub(crate) struct FeeResponse(pub FeeRate);