wip logging

dune-project

@@ -41,5 +41,6 @@
    jsont
    cohttp
    ptime
+   logs
   (ocamlformat :with-dev-setup)
    ))

mte.opam

@@ -28,6 +28,7 @@ depends: [
   "jsont"
   "cohttp"
   "ptime"
+  "logs"
   "ocamlformat" {with-dev-setup}
   "odoc" {with-doc}
 ]

src/dune

@@ -24,7 +24,11 @@
   fmt
   jsont
   cohttp
-  ptime))
+  ptime
+  logs
+  logs.fmt
+  logs.threaded
+  fmt.tty))
 
 (library ; crockford base32
  (name b32)

src/mte.ml

@@ -13,6 +13,60 @@
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>. *)
 
+let detail_tag : string Logs.Tag.def =
+  Logs.Tag.def "Detail tag" ~doc:"" Fmt.string
+
+let detail s = Logs.Tag.(empty |> add detail_tag s)
+let time_anchor = Ptime_clock.now () |> Ptime.to_span
+
+let log_level_color = function
+  | Logs.App -> `White
+  | Error -> `Red
+  | Warning -> `Yellow
+  | Info -> `Blue
+  | Debug -> `Magenta
+
+let reporter : Logs.reporter =
+  let open Fmt in
+  let pp_timestamp = styled `Faint (styled (`Fg `White) (fmt "%04.02f")) in
+  let pp_header ppf v =
+    let color = fst v |> log_level_color in
+    let pp = styled (`Fg color) Logs.pp_header in
+    pf ppf "%a" pp v
+  in
+  let pp_src_name ppf v =
+    let pp = using Logs.Src.name (styled `Cyan string) in
+    if not @@ Logs.Src.equal Logs.default v then pp ppf v
+  in
+  let pp_detail = option (styled `Green (fmt " (%s)")) in
+  let report src lvl ~over k msgf =
+    let ppf = stderr in
+    let k _ppf = over (); k () in
+    let with_detail h tags k user_fmt =
+      let detail = Option.bind tags (Logs.Tag.find detail_tag) in
+      let timestamp =
+        Ptime.sub_span (Ptime_clock.now ()) time_anchor
+        |> Option.map Ptime.to_float_s
+        |> Option.value ~default:0.
+      in
+      let k ppf = kpf k ppf "%a@." pp_detail detail in
+      let k ppf = kpf k ppf user_fmt in
+      kpf k ppf "%a %a %a" pp_timestamp timestamp pp_header (lvl, h) pp_src_name
+        src
+    in
+    msgf @@ fun ?header ?tags fmt -> with_detail header tags k fmt
+  in
+  { report }
+
+let () =
+  Fmt_tty.setup_std_outputs ~style_renderer:`Ansi_tty ~utf_8:true ();
+  Logs.set_reporter reporter;
+  Logs.set_level ~all:false (Some Logs.Debug);
+  Logs.Src.set_level Logs.default (Some Logs.Debug);
+  Logs_threaded.enable ();
+  Printexc.record_backtrace true;
+  ()
+
 let error_detail ?hint _status =
   let open Api in
   let code = -1 in
@@ -116,6 +170,7 @@ let routes =
   ]
 
 let () =
+  (*Logs.set_reporter (Logs_fmt.reporter ());*)
   let cfg =
     let port = Config.Exchange.port in
     let sockaddr = Unix.(ADDR_INET (inet_addr_loopback, port)) in
@@ -131,4 +186,5 @@ let () =
       [ Devices.db_connection; Devices.secmod_signkey; Devices.secmod_denom ]
   in
   let middlewares = Vif.Middlewares.[] in
+  Logs.info (fun m -> m ~tags:(detail "~~!") "Starting MTE server");
   Vif.run ~cfg ~devices ~middlewares routes env