P2p: add network/identity RPC

src/bin_node/node_config_command.ml

@@ -49,7 +49,7 @@ let reset (args : Node_shared_arg.t) =
 let init (args : Node_shared_arg.t) =
   if Sys.file_exists args.config_file then
     failwith
-      "Pre-existant config file at %s, use `reset`."
+      "Pre-existing config file at %s, use `reset`."
       args.config_file
   else
     Node_shared_arg.read_and_patch_config_file args >>=? fun cfg ->

src/lib_p2p/p2p.ml

@@ -578,6 +578,13 @@ let build_rpc_directory net =
       return net.versions
     end in
 
+  let dir =
+    RPC_directory.register0 dir P2p_services.S.identity begin fun () () ->
+      match net.pool with
+      | None -> failwith "The P2P layer is disabled."
+      | Some pool -> return (P2p_pool.config pool).identity.peer_id
+    end in
+
   let dir =
     RPC_directory.register0 dir P2p_services.S.stat begin fun () () ->
       match net.pool with

src/lib_shell_services/p2p_services.ml

@@ -49,6 +49,13 @@ let timeout_query =
 
 module S = struct
 
+  let identity =
+    RPC_service.get_service
+      ~description:"Return the node's identity"
+      ~query: RPC_query.empty
+      ~output: P2p_peer.Id.encoding
+      RPC_path.(root / "network" / "identity")
+
   let versions =
     RPC_service.get_service
       ~description:"Supported network layer versions."
@@ -81,6 +88,7 @@ module S = struct
 end
 
 open RPC_context
+let identity ctxt = make_call S.identity ctxt () () ()
 let stat ctxt = make_call S.stat ctxt () () ()
 let versions ctxt = make_call S.versions ctxt () () ()
 let events ctxt = make_streamed_call S.events ctxt () () ()

src/lib_shell_services/p2p_services.mli

@@ -25,6 +25,8 @@
 
 open RPC_context
 
+val identity: #simple -> P2p_peer.Id.t tzresult Lwt.t
+
 val stat: #simple -> P2p_stat.t tzresult Lwt.t
 
 val versions: #simple -> P2p_version.t list tzresult Lwt.t
@@ -36,6 +38,11 @@ val connect: #simple -> timeout:float -> P2p_point.Id.t -> unit tzresult Lwt.t
 
 module S : sig
 
+  val identity :
+    ([ `GET ], unit,
+     unit, unit, unit,
+     P2p_peer.Id.t) RPC_service.t
+
   val stat :
     ([ `GET ], unit,
      unit, unit, unit,