Adding optional public addresses for proxying (#5807)

* Adding optional public addresses for use in network configurations to allow for proxies in front of a node.

* Apply suggestions from code review

Co-Authored-By: Cecile Tonglet <cecile.tonglet@cecton.com>

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Cecile Tonglet <cecile.tonglet@cecton.com>
Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

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

@@ -41,6 +41,11 @@ pub struct NetworkParams {
 	#[structopt(long = "reserved-only")]
 	pub reserved_only: bool,
 
+	/// The public address that other nodes will use to connect to it.
+	/// This can be used if there's a proxy in front of this node.
+	#[structopt(long, value_name = "PUBLIC_ADDR")]
+	pub public_addr: Vec<Multiaddr>,
+
 	/// Listen on this multiaddress.
 	#[structopt(long = "listen-addr", value_name = "LISTEN_ADDR")]
 	pub listen_addr: Vec<Multiaddr>,
@@ -125,6 +130,8 @@ impl NetworkParams {
 			self.listen_addr.clone()
 		};
 
+		let public_addresses = self.public_addr.clone();
+
 		let mut boot_nodes = chain_spec.boot_nodes().to_vec();
 		boot_nodes.extend(self.bootnodes.clone());
 
@@ -138,7 +145,7 @@ impl NetworkParams {
 				NonReservedPeerMode::Accept
 			},
 			listen_addresses,
-			public_addresses: Vec::new(),
+			public_addresses,
 			notifications_protocols: Vec::new(),
 			node_key,
 			node_name: node_name.to_string(),