Update https-unikernel to released capnp-rpc 0.1 API

Also, separate out RPC encoding from application logic.

Signed-off-by: Thomas Leonard <thomas.leonard@docker.com>

projects/miragesdk/examples/https-unikernel/src/logging.ml

@@ -0,0 +1,38 @@
+module Actor = struct
+  type t = Fmt.style * string
+  let pp f (style, name) = Fmt.(styled style (const string name)) f ()
+  let tag = Logs.Tag.def "actor" pp
+end
+
+let pp_qid f = function
+  | None -> ()
+  | Some x ->
+    let s = Uint32.to_string x in
+    Fmt.(styled `Magenta (fun f x -> Fmt.pf f " (qid=%s)" x)) f s
+
+let reporter =
+  let report src level ~over k msgf =
+    let src = Logs.Src.name src in
+    msgf @@ fun ?header ?(tags=Logs.Tag.empty) fmt ->
+    let actor =
+      match Logs.Tag.find Actor.tag tags with
+      | Some x -> x
+      | None -> `Black, "------"
+    in
+    let qid = Logs.Tag.find Capnp_rpc.Debug.qid_tag tags in
+    let print _ =
+      Fmt.(pf stderr) "%a@." pp_qid qid;
+      over ();
+      k ()
+    in
+    Fmt.kpf print Fmt.stderr ("%a %a %a: @[" ^^ fmt ^^ "@]")
+      Fmt.(styled `Magenta string) (Printf.sprintf "%11s" src)
+      Logs_fmt.pp_header (level, header)
+      Actor.pp actor
+  in
+  { Logs.report = report }
+
+let init () =
+  Fmt_tty.setup_std_outputs ();
+  Logs.set_reporter reporter;
+  Logs.set_level (Some Logs.Info)