Node: Make sure fatal errors are properly printed

src/environment/v1/logging.mli

@@ -4,7 +4,7 @@ val log_info: ('a, Format.formatter, unit, unit) format4 -> 'a
 val log_notice: ('a, Format.formatter, unit, unit) format4 -> 'a
 val warn: ('a, Format.formatter, unit, unit) format4 -> 'a
 val log_error: ('a, Format.formatter, unit, unit) format4 -> 'a
-val fatal_error: ('a, Format.formatter, unit, 'b) format4 -> 'a
+val fatal_error: ('a, Format.formatter, unit, unit) format4 -> 'a
 
 val lwt_debug: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a
 val lwt_log_info: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a

src/node/main/node_run_command.ml

@@ -180,9 +180,12 @@ let init_rpc (rpc_config: Node_config_file.rpc) node =
           return (Some server)
 
 let init_signal () =
-  let handler id = try Lwt_exit.exit id with _ -> () in
-  ignore (Lwt_unix.on_signal Sys.sigint handler : Lwt_unix.signal_handler_id) ;
-  ignore (Lwt_unix.on_signal Sys.sigterm handler : Lwt_unix.signal_handler_id)
+  let handler name id = try
+      fatal_error "Received the %s signal, triggering shutdown." name ;
+      Lwt_exit.exit id
+    with _ -> () in
+  ignore (Lwt_unix.on_signal Sys.sigint (handler "INT") : Lwt_unix.signal_handler_id) ;
+  ignore (Lwt_unix.on_signal Sys.sigterm (handler "TERM") : Lwt_unix.signal_handler_id)
 
 let run ?verbosity ?sandbox (config : Node_config_file.t) =
   Node_data_version.ensure_data_dir config.data_dir >>=? fun () ->
@@ -201,6 +204,7 @@ let run ?verbosity ?sandbox (config : Node_config_file.t) =
   lwt_log_notice "Shutting down the RPC server..." >>= fun () ->
   Lwt_utils.may RPC_server.shutdown rpc >>= fun () ->
   lwt_log_notice "BYE (%d)" x >>= fun () ->
+  Logging.close () >>= fun () ->
   return ()
 
 let process sandbox verbosity args =

src/node/updater/updater.ml

@@ -34,7 +34,9 @@ let fork_test_network = Context.fork_test_network
 let datadir = ref None
 let get_datadir () =
   match !datadir with
-  | None -> fatal_error "not initialized"
+  | None ->
+      fatal_error "Node not initialized" ;
+      Lwt_exit.exit 1
   | Some m -> m
 
 let init dir =

src/utils/logging.ml

@@ -16,7 +16,7 @@ module type LOG = sig
   val log_notice: ('a, Format.formatter, unit, unit) format4 -> 'a
   val warn: ('a, Format.formatter, unit, unit) format4 -> 'a
   val log_error: ('a, Format.formatter, unit, unit) format4 -> 'a
-  val fatal_error: ('a, Format.formatter, unit, 'b) format4 -> 'a
+  val fatal_error: ('a, Format.formatter, unit, unit) format4 -> 'a
 
   val lwt_debug: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a
   val lwt_log_info: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a
@@ -56,10 +56,7 @@ module Make(S : sig val name: string end) : LOG = struct
   let log_notice fmt = ign_log_f ~section ~level:Lwt_log.Notice fmt
   let warn fmt = ign_log_f ~section ~level:Lwt_log.Warning fmt
   let log_error fmt = ign_log_f ~section ~level:Lwt_log.Error fmt
-  let fatal_error fmt =
-    Format.kasprintf
-      (fun s -> Lwt_log.ign_fatal ~section s; Lwt_exit.exit 1)
-      fmt
+  let fatal_error fmt = ign_log_f ~section ~level:Lwt_log.Fatal fmt
 
   let lwt_debug fmt = log_f ~section ~level:Lwt_log.Debug fmt
   let lwt_log_info fmt = log_f ~section ~level:Lwt_log.Info fmt
@@ -203,6 +200,9 @@ let init ?(template = default_template) output =
   Lwt_log.default := logger ;
   Lwt.return_unit
 
+let close () =
+  Lwt_log.close !Lwt_log.default
+
 type level = Lwt_log_core.level =
   | Debug
       (** Debugging message. They can be automatically removed by the

src/utils/logging.mli

@@ -14,7 +14,7 @@ module type LOG = sig
   val log_notice: ('a, Format.formatter, unit, unit) format4 -> 'a
   val warn: ('a, Format.formatter, unit, unit) format4 -> 'a
   val log_error: ('a, Format.formatter, unit, unit) format4 -> 'a
-  val fatal_error: ('a, Format.formatter, unit, 'b) format4 -> 'a
+  val fatal_error: ('a, Format.formatter, unit, unit) format4 -> 'a
 
   val lwt_debug: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a
   val lwt_log_info: ('a, Format.formatter, unit, unit Lwt.t) format4 -> 'a
@@ -85,4 +85,6 @@ end
 
 val init: ?template:template -> Output.t -> unit Lwt.t
 
+val close: unit -> unit Lwt.t
+
 val sections : string list ref

src/utils/lwt_exit.ml

@@ -17,12 +17,18 @@ let () =
     (function
       | Exit -> ()
       | exn ->
-          Format.eprintf
-            "@[Uncaught (asynchronous) exception (%d):@ %a@]"
-            (Unix.getpid ())
-            Error_monad.pp_exn exn ;
           let backtrace = Printexc.get_backtrace () in
-          if String.length backtrace <> 0 then
-            Format.eprintf "\n%s" backtrace ;
-          Format.eprintf "@." ;
+          Logging.Node.Main.fatal_error "@[<v 2>%a%a@]"
+            (fun ppf exn ->
+               Format.fprintf ppf
+                 "@[Uncaught (asynchronous) exception (%d):@ %a@]"
+                 (Unix.getpid ())
+                 Error_monad.pp_exn exn)
+            exn
+            (fun ppf backtrace ->
+               if String.length backtrace <> 0 then
+                 Format.fprintf ppf
+                   "@,Backtrace:@,  @[<h>%a@]"
+                   Format.pp_print_text backtrace)
+            backtrace ;
           Lwt.wakeup exit_wakener 1)