Source file app.ml

open Lwt.Syntax

let log_src = Logs.Src.create ~doc:"Sihl app" "sihl.app"

module Logger = (val Logs.src_log log_src : Logs.LOG)

type t =
  { services : Container.Service.t list
  ; before_start : unit -> unit Lwt.t
  ; after_stop : unit -> unit Lwt.t
  }

let empty =
  { services = []
  ; before_start = (fun _ -> Lwt.return ())
  ; after_stop = (fun _ -> Lwt.return ())
  }
;;

let with_services services app = { app with services }
let before_start before_start app = { app with before_start }
let after_stop after_stop app = { app with after_stop }

(* TODO [jerben] 0. store ref to current app and start ctx 1. loop forever (in
   Lwt_main.run) 2. when command finishes, exit loop 3. when SIGINT comes, exit loop 4.
   call stop app let stop app ctx = let* () = app.before_stop ctx in print_endline "CORE:
   Stop services"; let* () = Container.stop_services ctx app.services in print_endline
   "CORE: Services stopped"; app.after_stop ctx *)

let starting_commands service =
  (* When executing a starting command, the service that publishes that command and all
     its dependencies is started before the command is run *)
  List.map
    (fun command ->
      let fn args =
        let* _ = Container.start_services [ service ] in
        command.Command.fn args
      in
      Command.{ command with fn })
    (Container.Service.commands service)
;;

let run' ?(commands = []) ?(log_reporter = Log.default_reporter) ?args app =
  (* Set the logger up as first thing so we can log *)
  Logs.set_reporter (log_reporter ());
  Logger.debug (fun m -> m "Setup service configurations");
  let configurations =
    List.map (fun service -> Container.Service.configuration service) app.services
  in
  let* file_configuration = Configuration.read_env_file () in
  Configuration.store file_configuration;
  let* () = app.before_start () in
  Configuration.require configurations;
  (* iter all schema and check if env vars here *)
  let configuration_commands = Configuration.commands configurations in
  Logger.debug (fun m -> m "Setup service commands");
  let service_commands = app.services |> List.map starting_commands |> List.concat in
  let commands = List.concat [ configuration_commands; service_commands; commands ] in
  Command.run commands args
;;

let run ?(commands = []) ?(log_reporter = Log.default_reporter) ?args app =
  Lwt_main.run
  @@
  match args with
  | Some args -> run' ~commands ~log_reporter ~args app
  | None -> run' ~commands ~log_reporter app
;;