lncfg: add new PrunedNodeMaxPeers config option/flag

chainreg/chainregistry.go

@@ -397,6 +397,7 @@ func NewChainControl(cfg *Config) (*ChainControl, error) {
 			ZMQTxHost:          bitcoindMode.ZMQPubRawTx,
 			ZMQReadDeadline:    5 * time.Second,
 			Dialer:             cfg.Dialer,
+			PrunedModeMaxPeers: bitcoindMode.PrunedNodeMaxPeers,
 		})
 		if err != nil {
 			return nil, err

config.go

@@ -183,6 +183,8 @@ var (
 	defaultBitcoindEstimateMode = "CONSERVATIVE"
 	bitcoindEstimateModes       = [2]string{"ECONOMICAL", defaultBitcoindEstimateMode}
 
+	defaultPrunedNodeMaxPeers = 4
+
 	defaultSphinxDbName = "sphinxreplay.db"
 )
 
@@ -392,9 +394,10 @@ func DefaultConfig() Config {
 			RPCCert: defaultBtcdRPCCertFile,
 		},
 		BitcoindMode: &lncfg.Bitcoind{
-			Dir:          defaultBitcoindDir,
-			RPCHost:      defaultRPCHost,
-			EstimateMode: defaultBitcoindEstimateMode,
+			Dir:                defaultBitcoindDir,
+			RPCHost:            defaultRPCHost,
+			EstimateMode:       defaultBitcoindEstimateMode,
+			PrunedNodeMaxPeers: defaultPrunedNodeMaxPeers,
 		},
 		Litecoin: &lncfg.Chain{
 			MinHTLCIn:     chainreg.DefaultLitecoinMinHTLCInMSat,
@@ -411,9 +414,10 @@ func DefaultConfig() Config {
 			RPCCert: defaultLtcdRPCCertFile,
 		},
 		LitecoindMode: &lncfg.Bitcoind{
-			Dir:          defaultLitecoindDir,
-			RPCHost:      defaultRPCHost,
-			EstimateMode: defaultBitcoindEstimateMode,
+			Dir:                defaultLitecoindDir,
+			RPCHost:            defaultRPCHost,
+			EstimateMode:       defaultBitcoindEstimateMode,
+			PrunedNodeMaxPeers: defaultPrunedNodeMaxPeers,
 		},
 		NeutrinoMode: &lncfg.Neutrino{
 			UserAgentName:    neutrino.UserAgentName,

lncfg/bitcoind.go

@@ -3,11 +3,12 @@ package lncfg
 // Bitcoind holds the configuration options for the daemon's connection to
 // bitcoind.
 type Bitcoind struct {
-	Dir            string `long:"dir" description:"The base directory that contains the node's data, logs, configuration file, etc."`
-	RPCHost        string `long:"rpchost" description:"The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used."`
-	RPCUser        string `long:"rpcuser" description:"Username for RPC connections"`
-	RPCPass        string `long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
-	ZMQPubRawBlock string `long:"zmqpubrawblock" description:"The address listening for ZMQ connections to deliver raw block notifications"`
-	ZMQPubRawTx    string `long:"zmqpubrawtx" description:"The address listening for ZMQ connections to deliver raw transaction notifications"`
-	EstimateMode   string `long:"estimatemode" description:"The fee estimate mode. Must be either ECONOMICAL or CONSERVATIVE."`
+	Dir                string `long:"dir" description:"The base directory that contains the node's data, logs, configuration file, etc."`
+	RPCHost            string `long:"rpchost" description:"The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used."`
+	RPCUser            string `long:"rpcuser" description:"Username for RPC connections"`
+	RPCPass            string `long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
+	ZMQPubRawBlock     string `long:"zmqpubrawblock" description:"The address listening for ZMQ connections to deliver raw block notifications"`
+	ZMQPubRawTx        string `long:"zmqpubrawtx" description:"The address listening for ZMQ connections to deliver raw transaction notifications"`
+	EstimateMode       string `long:"estimatemode" description:"The fee estimate mode. Must be either ECONOMICAL or CONSERVATIVE."`
+	PrunedNodeMaxPeers int    `long:"pruned-node-max-peers" description:"The maximum number of peers lnd will choose from the backend node to retrieve pruned blocks from. This only applies to pruned nodes."`
 }

sample-lnd.conf

@@ -536,6 +536,10 @@ bitcoin.node=btcd
 ; If unset, the default value is "CONSERVATIVE".
 ; bitcoind.estimatemode=CONSERVATIVE
 
+; The maximum number of peers lnd will choose from the backend node to retrieve
+; pruned blocks from. This only applies to pruned nodes.
+; bitcoind.pruned-node-max-peers=4
+
 [neutrino]
 
 ; Connect only to the specified peers at startup. This creates a persistent
@@ -706,6 +710,10 @@ litecoin.node=ltcd
 ; If unset, the default value is "CONSERVATIVE".
 ; litecoind.estimatemode=CONSERVATIVE
 
+; The maximum number of peers lnd will choose from the backend node to retrieve
+; pruned blocks from. This only applies to pruned nodes.
+; litecoind.pruned-node-max-peers=4
+
 [autopilot]
 
 ; If the autopilot agent should be active or not. The autopilot agent will