expose setting kademlia replication factor through node CLI (#14391)

* expose kademlia replication factor through node CLI

* set default CLI flag value for kademlia_replication_factor

Co-authored-by: Bastian Köcher <git@kchr.de>

* wrap CLI value as Option

* make kademlia replication factor non-optional

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/client/cli/src/params/network_params.rs

@@ -28,7 +28,7 @@ use sc_service::{
 	config::{Multiaddr, MultiaddrWithPeerId},
 	ChainSpec, ChainType,
 };
-use std::{borrow::Cow, path::PathBuf};
+use std::{borrow::Cow, num::NonZeroUsize, path::PathBuf};
 
 /// Parameters used to create the network configuration.
 #[derive(Debug, Clone, Args)]
@@ -121,6 +121,13 @@ pub struct NetworkParams {
 	#[arg(long)]
 	pub kademlia_disjoint_query_paths: bool,
 
+	/// Kademlia replication factor determines to how many closest peers a record is replicated to.
+	///
+	/// Discovery mechanism requires successful replication to all
+	/// `kademlia_replication_factor` peers to consider record successfully put.
+	#[arg(long, default_value = "20")]
+	pub kademlia_replication_factor: NonZeroUsize,
+
 	/// Join the IPFS network and serve transactions over bitswap protocol.
 	#[arg(long)]
 	pub ipfs_server: bool,
@@ -233,6 +240,7 @@ impl NetworkParams {
 			enable_dht_random_walk: !self.reserved_only,
 			allow_non_globals_in_dht,
 			kademlia_disjoint_query_paths: self.kademlia_disjoint_query_paths,
+			kademlia_replication_factor: self.kademlia_replication_factor,
 			yamux_window_size: None,
 			ipfs_server: self.ipfs_server,
 			sync_mode: self.sync.into(),