Add option to include headers in Esplora config

This is useful if the esplora server has a form of authentication in
front of it

Author: benthecarman

src/builder.rs

@@ -87,6 +87,7 @@ const LSPS_HARDENED_CHILD_INDEX: u32 = 577;
 enum ChainDataSourceConfig {
 	Esplora {
 		server_url: String,
+		headers: HashMap<String, String>,
 		sync_config: Option<EsploraSyncConfig>,
 	},
 	Electrum {
@@ -294,9 +295,27 @@ impl NodeBuilder {
 	/// information.
 	pub fn set_chain_source_esplora(
 		&mut self, server_url: String, sync_config: Option<EsploraSyncConfig>,
+	) -> &mut Self {
+		self.chain_data_source_config = Some(ChainDataSourceConfig::Esplora {
+			server_url,
+			headers: Default::default(),
+			sync_config,
+		});
+		self
+	}
+
+	/// Configures the [`Node`] instance to source its chain data from the given Esplora server.
+	/// The given `headers` will be included in all requests to the Esplora server, typically used for
+	/// authentication purposes.
+	///
+	/// If no `sync_config` is given, default values are used. See [`EsploraSyncConfig`] for more
+	/// information.
+	pub fn set_chain_source_esplora_with_headers(
+		&mut self, server_url: String, headers: HashMap<String, String>,
+		sync_config: Option<EsploraSyncConfig>,
 	) -> &mut Self {
 		self.chain_data_source_config =
-			Some(ChainDataSourceConfig::Esplora { server_url, sync_config });
+			Some(ChainDataSourceConfig::Esplora { server_url, headers, sync_config });
 		self
 	}
 
@@ -1117,10 +1136,11 @@ fn build_with_store_internal(
 	));
 
 	let chain_source = match chain_data_source_config {
-		Some(ChainDataSourceConfig::Esplora { server_url, sync_config }) => {
+		Some(ChainDataSourceConfig::Esplora { server_url, headers, sync_config }) => {
 			let sync_config = sync_config.unwrap_or(EsploraSyncConfig::default());
 			Arc::new(ChainSource::new_esplora(
 				server_url.clone(),
+				headers.clone(),
 				sync_config,
 				Arc::clone(&wallet),
 				Arc::clone(&fee_estimator),
@@ -1187,6 +1207,7 @@ fn build_with_store_internal(
 			let sync_config = EsploraSyncConfig::default();
 			Arc::new(ChainSource::new_esplora(
 				server_url.clone(),
+				HashMap::new(),
 				sync_config,
 				Arc::clone(&wallet),
 				Arc::clone(&fee_estimator),

src/chain/mod.rs

@@ -233,21 +233,31 @@ pub(crate) enum ChainSource {
 
 impl ChainSource {
 	pub(crate) fn new_esplora(
-		server_url: String, sync_config: EsploraSyncConfig, onchain_wallet: Arc<Wallet>,
-		fee_estimator: Arc<OnchainFeeEstimator>, tx_broadcaster: Arc<Broadcaster>,
-		kv_store: Arc<DynStore>, config: Arc<Config>, logger: Arc<Logger>,
-		node_metrics: Arc<RwLock<NodeMetrics>>,
+		server_url: String, headers: HashMap<String, String>, sync_config: EsploraSyncConfig,
+		onchain_wallet: Arc<Wallet>, fee_estimator: Arc<OnchainFeeEstimator>,
+		tx_broadcaster: Arc<Broadcaster>, kv_store: Arc<DynStore>, config: Arc<Config>,
+		logger: Arc<Logger>, node_metrics: Arc<RwLock<NodeMetrics>>,
 	) -> Self {
 		// FIXME / TODO: We introduced this to make `bdk_esplora` work separately without updating
 		// `lightning-transaction-sync`. We should revert this as part of of the upgrade to LDK 0.2.
 		let mut client_builder_0_11 = esplora_client_0_11::Builder::new(&server_url);
 		client_builder_0_11 = client_builder_0_11.timeout(DEFAULT_ESPLORA_CLIENT_TIMEOUT_SECS);
+
+		for (header_name, header_value) in &headers {
+			client_builder_0_11 = client_builder_0_11.header(header_name, header_value);
+		}
+
 		let esplora_client_0_11 = client_builder_0_11.build_async().unwrap();
 		let tx_sync =
 			Arc::new(EsploraSyncClient::from_client(esplora_client_0_11, Arc::clone(&logger)));
 
 		let mut client_builder = esplora_client::Builder::new(&server_url);
 		client_builder = client_builder.timeout(DEFAULT_ESPLORA_CLIENT_TIMEOUT_SECS);
+
+		for (header_name, header_value) in &headers {
+			client_builder = client_builder.header(header_name, header_value);
+		}
+
 		let esplora_client = client_builder.build_async().unwrap();
 
 		let onchain_wallet_sync_status = Mutex::new(WalletSyncStatus::Completed);