expose peer information via rpc (#1362)

* expose peer information via rpc

* fixes tests

* cleanup

Co-Authored-By: xlc <xlchen1291@gmail.com>

* Update docs

Co-Authored-By: xlc <xlchen1291@gmail.com>

* Add missing docs

* keep original type for PeerInfo best_hash/best_number

* cleanup

* Update mod.rs

substrate/core/network/src/lib.rs

@@ -69,7 +69,7 @@ pub use protocol::{ProtocolStatus, PeerInfo, Context};
 pub use sync::{Status as SyncStatus, SyncState};
 pub use network_libp2p::{
     NodeIndex, ProtocolId, Severity, Protocol, Multiaddr,
-    obtain_private_key, multiaddr,
+    obtain_private_key, multiaddr, PeerId, PublicKey
 };
 pub use message::{generic as generic_message, RequestId, Status as StatusMessage};
 pub use error::Error;

substrate/core/network/src/protocol.rs

@@ -240,6 +240,20 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		}
 	}
 
+	pub fn peers(&self) -> Vec<(NodeIndex, PeerInfo<B>)> {
+		self.context_data.peers.read().iter().map(|(idx, p)| {
+			(
+				*idx,
+				PeerInfo {
+					roles: p.roles,
+					protocol_version: p.protocol_version,
+					best_hash: p.best_hash,
+					best_number: p.best_number,
+				}
+			)
+		}).collect()
+	}
+
 	pub fn handle_packet(&self, io: &mut SyncIo, who: NodeIndex, mut data: &[u8]) {
 		let message: Message<B> = match Decode::decode(&mut data) {
 			Some(m) => m,

substrate/core/network/src/service.rs

@@ -26,7 +26,7 @@ use network_libp2p::{RegisteredProtocol, parse_str_addr, Protocol as Libp2pProto
 use io::NetSyncIo;
 use consensus::import_queue::{ImportQueue, Link};
 use consensus_gossip::ConsensusGossip;
-use protocol::{self, Protocol, ProtocolContext, Context, ProtocolStatus};
+use protocol::{self, Protocol, ProtocolContext, Context, ProtocolStatus, PeerInfo};
 use config::Params;
 use error::Error;
 use specialization::NetworkSpecialization;
@@ -45,6 +45,8 @@ const PROPAGATE_TIMEOUT: Duration = Duration::from_millis(5000);
 pub trait SyncProvider<B: BlockT>: Send + Sync {
 	/// Get sync status
 	fn status(&self) -> ProtocolStatus<B>;
+	/// Get currently connected peers
+	fn peers(&self) -> Vec<(NodeIndex, Option<PeerId>, PeerInfo<B>)>;
 }
 
 /// Minimum Requirements for a Hash within Networking
@@ -228,6 +230,14 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> SyncProvider<
 	fn status(&self) -> ProtocolStatus<B> {
 		self.handler.status()
 	}
+
+	fn peers(&self) -> Vec<(NodeIndex, Option<PeerId>, PeerInfo<B>)> {
+		let peers = self.handler.peers();
+		let network = self.network.lock();
+		peers.into_iter().map(|(idx, info)| {
+			(idx, network.peer_id_of_node(idx).map(|p| p.clone()), info)
+		}).collect::<Vec<_>>()
+	}
 }
 
 /// Trait for managing network