Merge pull request #34 from jestabro/restart-from-cache

T7980: cache running config on commit completion and add option --reload-active-config

Author: dmbaturin

src/session.ml

@@ -251,23 +251,51 @@ let save w s file =
     | Error e -> raise (Session_error (Printf.sprintf "Error saving config: %s" e))
     | Ok () -> s
 
-let prepare_commit ?(dry_run=false) w config id pid sudo_user user =
-    let at = w.running_config in
-    let rt = w.reference_tree in
+let write_running_cache w =
     let vc = w.vyconf_config in
-    let () =
-        try
-            IC.write_internal at (FP.concat vc.session_dir vc.running_cache)
-        with
-            Vyos1x.Internal.Write_error msg -> raise (Session_error msg)
-    in
-    let () =
-        try
-            IC.write_internal config (FP.concat vc.session_dir vc.session_cache)
-        with
-            Vyos1x.Internal.Write_error msg -> raise (Session_error msg)
-    in
-    CC.make_commit_data ~dry_run:dry_run rt at config id pid sudo_user user
+    try
+        let () =
+            IC.write_internal_atomic
+            w.running_config
+            (FP.concat vc.session_dir vc.running_cache);
+        in Ok ()
+    with
+        Vyos1x.Internal.Write_error msg ->
+            let msg =
+                Printf.sprintf "Write error caching running config: %s" msg
+            in Error msg
+
+let write_session_cache w config =
+    let vc = w.vyconf_config in
+    try
+        let () =
+            IC.write_internal
+            config
+            (FP.concat vc.session_dir vc.session_cache);
+        in Ok ()
+    with
+        Vyos1x.Internal.Write_error msg ->
+            let msg =
+                Printf.sprintf "Write error caching session config: %s" msg
+            in Error msg
+
+let prepare_commit ?(dry_run=false) w s config id =
+    let opt_running = write_running_cache w in
+    let opt_session = write_session_cache w config in
+    match opt_running, opt_session with
+    | Ok (), Ok () ->
+        Ok (CC.make_commit_data
+            ~dry_run:dry_run
+            w.reference_tree
+            w.running_config
+            config
+            id
+            s.client_pid
+            s.client_sudo_user
+            s.client_user)
+    | Error msg, Ok () -> Error msg
+    | Ok (), Error msg -> Error msg
+    | Error msg1, Error msg2 -> Error (Printf.sprintf "%s\n %s" msg1 msg2)
 
 let post_process_commit w s ((c_data: CC.commit_data), proposed_config) =
     let ident n v y =

src/session.mli

@@ -69,7 +69,11 @@ val list_children : world -> session_data -> string list -> string list
 
 val string_of_op : cfg_op -> string
 
-val prepare_commit : ?dry_run:bool -> world -> Vyos1x.Config_tree.t -> string -> int32 -> string -> string -> Commitd_client.Commit.commit_data
+val write_running_cache : world -> (unit, string) result
+
+val write_session_cache : world -> Vyos1x.Config_tree.t -> (unit, string) result
+
+val prepare_commit : ?dry_run:bool -> world -> session_data -> Vyos1x.Config_tree.t -> string -> (Commitd_client.Commit.commit_data, string) result
 
 val post_process_commit : world -> session_data -> Commitd_client.Commit.commit_data * Vyos1x.Config_tree.t -> Vyos1x.Config_tree.t * Vyos1x.Config_tree.t
 

src/startup.ml

@@ -94,6 +94,16 @@ let load_config_failsafe main fallback =
             | Error msg -> panic (Printf.sprintf "Failed to load fallback config %s: %s, exiting" fallback msg)
         end
 
+module IC = Vyos1x.Internal.Make(Vyos1x.Config_tree)
+
+let load_config_cache cache_file =
+    try
+        let cached_config = IC.read_internal cache_file in
+        log_info @@ Printf.sprintf "Reading active config from %s" cache_file;
+        Ok cached_config
+    with Vyos1x.Internal.Read_error msg ->
+        Error (Printf.sprintf "Failed to load active config %s: %s, exiting" cache_file msg)
+
 (* Load interface definitions from a directory into a reference tree *)
 let load_interface_definitions dir =
     let open Vyos1x.Reference_tree in
@@ -111,11 +121,11 @@ let load_interface_definitions dir =
         | Error msg -> Error msg end
     with Bad_interface_definition msg -> Error msg
 
-module I = Vyos1x.Internal.Make(Vyos1x.Reference_tree)
+module IR = Vyos1x.Internal.Make(Vyos1x.Reference_tree)
 
 let read_reference_tree file =
     try
-        let reftree = I.read_internal file in
+        let reftree = IR.read_internal file in
         log_info @@ Printf.sprintf "Reading interface definitions from %s" file;
         Ok reftree
-    with Sys_error msg -> Error msg
+    with Vyos1x.Internal.Read_error msg -> Error msg

src/startup.mli

@@ -14,6 +14,8 @@ val create_server :
     (Lwt_unix.file_descr * Lwt_unix.sockaddr -> unit Lwt.t) ->
     Lwt_unix.file_descr -> unit -> 'a Lwt.t
 
+val load_config_cache : string -> (Vyos1x.Config_tree.t, string) result
+
 val load_config_failsafe : string -> string -> Vyos1x.Config_tree.t
 
 val load_interface_definitions : string -> (Vyos1x.Reference_tree.t, string) result

src/vyconfd.ml

@@ -25,6 +25,7 @@ let config_file = ref defaults.config_file
 let basepath = ref "/"
 let log_file = ref None
 let legacy_config_path = ref false
+let reload_active_config = ref false
 
 (* Global data *)
 let sessions : (string, Session.session_data) Hashtbl.t = Hashtbl.create 10
@@ -43,6 +44,7 @@ let args = [
     ("--version", Arg.Unit (fun () -> print_endline @@ Version.version_info (); exit 0), "Print version and exit");
     ("--legacy-config-path", Arg.Unit (fun () -> legacy_config_path := true),
     (Printf.sprintf "Load config file from legacy path %s" defaults.legacy_config_path));
+    ("--reload-active-config", Arg.Unit (fun () -> reload_active_config := true), "Reload active config file");
    ]
 let usage = "Usage: " ^ Sys.argv.(0) ^ " [options]"
 
@@ -274,16 +276,13 @@ let commit world token (req: request_commit) =
     let proposed_config = Session.get_proposed_config world s in
     let req_dry_run = Option.value req.dry_run ~default:false in
     let commit_data =
-        Session.prepare_commit
-        ~dry_run:req_dry_run
-        world
-        proposed_config
-        token
-        s.client_pid
-        s.client_sudo_user
-        s.client_user
+        Session.prepare_commit ~dry_run:req_dry_run world s proposed_config token
     in
-    let%lwt received_commit_data = VC.do_commit commit_data in
+    match commit_data with
+    | Error msg ->
+        Lwt.return {response_tmpl with status=Internal_error; error=(Some msg)}
+    | Ok c_data ->
+    let%lwt received_commit_data = VC.do_commit c_data in
     let%lwt result_commit_data =
         Lwt.return (CC.commit_update received_commit_data)
     in
@@ -314,12 +313,25 @@ let commit world token (req: request_commit) =
                         world.Session.running_config
                         post_proposed;
                         aux_changeset = []; }
-                in Hashtbl.replace sessions token session
+                in
+                Hashtbl.replace sessions token session
             else ();
 
-            let success, msg_str =
+            let write_msg =
+                if not req_dry_run then
+                    match Session.write_running_cache world with
+                    | Ok () -> ""
+                    | Error msg -> msg
+                else ""
+            in
+            let success, result_msg =
                 result_commit_data.result.success, result_commit_data.result.out
             in
+            let msg_str =
+                match write_msg with
+                | "" -> result_msg
+                | _ -> Printf.sprintf "%s\n %s" result_msg write_msg
+            in
             match success with
             | true -> Lwt.return {response_tmpl with status=Success; output=(Some msg_str)}
             | false -> Lwt.return {response_tmpl with status=Fail; output=(Some msg_str)}
@@ -426,6 +438,14 @@ let read_reference_tree file =
     | Ok r -> r
     | Error s -> Startup.panic s
 
+let init_write_cache world =
+    (* initial cache of running config; this will be unnecessary once
+       vyconfd is started at boot *)
+    let res = Session.write_running_cache world in
+    match res with
+    | Ok _ ->  ()
+    | Error msg -> (Lwt_log.error msg) |> Lwt.ignore_result
+
 let make_world config dirs =
     let open Session in
     (* the reference_tree json file is generated at vyos-1x build time *)
@@ -446,8 +466,23 @@ let () =
       | false -> (FP.concat vc.config_dir vc.primary_config)
   in
   let failsafe_config = (FP.concat vc.config_dir vc.fallback_config) in
+  let restart_cache = (FP.concat vc.session_dir vc.running_cache) in
   let config =
-      Startup.load_config_failsafe primary_config failsafe_config
+      match !reload_active_config with
+      | true -> let res = Startup.load_config_cache restart_cache in
+                begin
+                match res with
+                | Ok c -> c
+                | Error msg ->
+                    let () = (Lwt_log.error msg) |> Lwt.ignore_result in
+                    Startup.load_config_failsafe primary_config failsafe_config
+                end
+      | false -> Startup.load_config_failsafe primary_config failsafe_config
   in
   let world = Session.{world with running_config=config} in
+  let () =
+      match !reload_active_config with
+      | true -> ()
+      | false -> init_write_cache world
+  in
   Lwt_main.run @@ main_loop !basepath world ()