albatross/app/vmmd.ml

235 lines
8.4 KiB
OCaml

(* (c) 2017 Hannes Mehnert, all rights reserved *)
open Vmm_cli
open Vmm_core
type stats = {
start : Ptime.t ;
vm_created : int ;
vm_destroyed : int ;
}
let s = ref { start = Ptime_clock.now () ; vm_created = 0 ; vm_destroyed = 0 }
let pp_stats ppf s =
let diff = Ptime.(diff (Ptime_clock.now ()) s.start) in
Fmt.pf ppf "up %a: %d vms created, %d vms destroyed, %d running"
Ptime.Span.pp diff
s.vm_created s.vm_destroyed (s.vm_created - s.vm_destroyed)
open Lwt.Infix
let version = `AV3
let state = ref (Vmm_vmmd.init version)
let create process cont =
match cont !state with
| Error (`Msg msg) ->
Logs.err (fun m -> m "create continuation failed %s" msg) ;
Lwt.return_unit
| Ok (state', out, name, vm) ->
state := state' ;
s := { !s with vm_created = succ !s.vm_created } ;
Lwt.async (fun () ->
Vmm_lwt.wait_and_clear vm.Unikernel.pid >>= fun r ->
let state', out' = Vmm_vmmd.handle_shutdown !state name vm r in
state := state' ;
s := { !s with vm_destroyed = succ !s.vm_destroyed } ;
(process "handle shutdown" out' >|= fun _ -> ()) >|= fun () ->
let state', waiter_opt = Vmm_vmmd.waiter !state name in
state := state' ;
(match waiter_opt with
| None -> ()
| Some wakeme -> Lwt.wakeup wakeme ())) ;
(process "setting up statistics, log, reply" out >|= fun _ -> ())
let register who header =
match Vmm_vmmd.register !state who Lwt.task with
| None -> Error (`Data (header, `Failure "task already registered"))
| Some (state', task) -> state := state' ; Ok task
let handle out fd addr =
Logs.debug (fun m -> m "connection from %a" Vmm_lwt.pp_sockaddr addr) ;
(* now we need to read a packet and handle it
(1)
(a) easy for info (look up name/prefix in resources)
(b) destroy looks up vm in resources, executes kill (wait for pid will do the cleanup)
logs "destroy issued"
(c) create initiates the vm startup procedure:
write image file, create fifo, create tap(s), send fifo to console
-- Lwt effects happen (console) --
executes solo5-hvt + waiter, send stats pid and taps, inserts await into state, logs "created vm"
-- Lwt effects happen (stats, logs, wait_and_clear) --
(2) goto (1)
*)
let process txt wires =
Lwt_list.fold_left_s (fun r data ->
match r, data with
| Ok (), (#Vmm_vmmd.service_out as o) -> out o
| Ok (), `Data wire ->
(* rather: terminate connection *)
Vmm_lwt.write_wire fd wire >|= fun _ ->
Ok ()
| Error e, _ -> Lwt.return (Error e))
(Ok ()) wires >|= function
| Ok () -> Ok ()
| Error (`Msg msg) ->
Logs.err (fun m -> m "error in processing data %s: %s" txt msg) ;
Error ()
in
let rec loop () =
Logs.debug (fun m -> m "now reading") ;
Vmm_lwt.read_wire fd >>= function
| Error _ ->
Logs.err (fun m -> m "error while reading") ;
Lwt.return_unit
| Ok wire ->
Logs.debug (fun m -> m "read sth") ;
let state', data, next = Vmm_vmmd.handle_command !state wire in
state := state' ;
process "handle_command" data >>= function
| Error () -> Lwt.return_unit
| Ok () -> match next with
| `Loop -> loop ()
| `End -> Lwt.return_unit
| `Create cont -> create process cont
| `Wait (who, out) ->
(match register who (fst wire) with
| Error out' -> process "wait" [ out' ] >|= ignore
| Ok task ->
task >>= fun () ->
process "wait" [ out ] >|= ignore)
| `Wait_and_create (who, next) ->
(match register who (fst wire) with
| Error out' -> process "wait and create" [ out' ] >|= ignore
| Ok task ->
task >>= fun () ->
let state', data, n = next !state in
state := state' ;
process "wait and create" data >>= fun _ ->
match n with
| `End -> Lwt.return_unit
| `Create cont -> create process cont >|= ignore)
in
loop () >>= fun () ->
Vmm_lwt.safe_close fd
let init_sock sock =
let name = socket_path sock in
let c = Lwt_unix.(socket PF_UNIX SOCK_STREAM 0) in
Lwt_unix.set_close_on_exec c ;
Lwt.catch (fun () ->
Lwt_unix.(connect c (ADDR_UNIX name)) >|= fun () -> Some c)
(fun e ->
Logs.warn (fun m -> m "error %s connecting to socket %s"
(Printexc.to_string e) name) ;
(Lwt.catch (fun () -> Lwt_unix.close c) (fun _ -> Lwt.return_unit)) >|= fun () ->
None)
let create_mbox sock =
init_sock sock >|= function
| None -> None
| Some fd ->
let mvar = Lwt_mvar.create_empty () in
(* could be more elaborate:
if <log> fails, we can reconnect and spit our more log messages to the new socket
if <console> fails, all running VMs terminate, so we can terminate as well ;)
if <stat> fails, we'd need to retransmit all VM info to stat (or stat has to ask at connect) *)
let rec loop () =
Lwt_mvar.take mvar >>= fun data ->
Logs.debug (fun m -> m "writing %a" Vmm_commands.pp_wire data) ;
Vmm_lwt.write_wire fd data >>= function
| Ok () -> loop ()
| Error `Exception -> invalid_arg ("exception while writing to " ^ Fmt.to_to_string pp_socket sock) ;
in
Lwt.async loop ;
Some (mvar, fd, Lwt_mutex.create ())
let server_socket sock =
let name = socket_path sock in
(Lwt_unix.file_exists name >>= function
| true -> Lwt_unix.unlink name
| false -> Lwt.return_unit) >>= fun () ->
let s = Lwt_unix.(socket PF_UNIX SOCK_STREAM 0) in
Lwt_unix.set_close_on_exec s ;
Lwt_unix.(bind s (ADDR_UNIX name)) >|= fun () ->
Lwt_unix.listen s 1 ;
s
let rec stats_loop () =
Logs.info (fun m -> m "%a" pp_stats !s) ;
Lwt_unix.sleep 600. >>= fun () ->
stats_loop ()
let jump _ =
Sys.(set_signal sigpipe Signal_ignore);
Lwt_main.run
(server_socket `Vmmd >>= fun ss ->
(create_mbox `Log >|= function
| None -> invalid_arg "cannot connect to log socket"
| Some l -> l) >>= fun (l, l_fd, l_mut) ->
let self_destruct () =
Vmm_vmmd.kill !state ;
(* not too happy about the sleep here, but cleaning up resources is
really important (fifos, vm images, tap devices) - which is done in
asynchronous (waiter tasks)
*)
Lwt_unix.sleep 1. >>= fun () ->
Vmm_lwt.safe_close ss
in
Sys.(set_signal sigterm (Signal_handle (fun _ -> Lwt.async self_destruct)));
(create_mbox `Console >|= function
| None -> invalid_arg "cannot connect to console socket"
| Some c -> c) >>= fun (c, c_fd, c_mut) ->
create_mbox `Stats >>= fun s ->
let write_reply (header, cmd) name mvar fd mut =
Lwt_mutex.with_lock mut (fun () ->
Lwt_mvar.put mvar (header, cmd) >>= fun () ->
Vmm_lwt.read_wire fd) >|= function
| Ok (header', reply) ->
if not Vmm_commands.(version_eq header.version header'.version) then
Error (`Msg ("wrong version in reply from " ^ name))
else if not Vmm_commands.(Int64.equal header.sequence header'.sequence) then
Error (`Msg (
Fmt.strf "wrong id %Lu (expected %Lu) in reply from %s"
header'.Vmm_commands.sequence header.Vmm_commands.sequence name))
else begin match reply with
| `Success _ -> Ok ()
| `Failure msg -> Error (`Msg (msg ^ " from " ^ name))
| _ -> Error (`Msg ("unexpected data from " ^ name))
end
| Error _ -> Error (`Msg ("error in read from " ^ name))
in
let out = function
| `Stat wire ->
begin match s with
| None -> Lwt.return (Ok ())
| Some (s, s_fd, s_mut) -> write_reply wire "stats" s s_fd s_mut
end
| `Log wire -> write_reply wire "log" l l_fd l_mut
| `Cons wire -> write_reply wire "console" c c_fd c_mut
in
Lwt.async stats_loop ;
Lwt.catch (fun () ->
let rec loop () =
Lwt_unix.accept ss >>= fun (fd, addr) ->
Lwt_unix.set_close_on_exec fd ;
Lwt.async (fun () -> handle out fd addr) ;
loop ()
in
loop ())
(fun e ->
Logs.err (fun m -> m "exception %s, shutting down" (Printexc.to_string e));
self_destruct ()))
open Cmdliner
let cmd =
Term.(const jump $ setup_log),
Term.info "vmmd" ~version:"%%VERSION_NUM%%"
let () = match Term.eval cmd with `Ok () -> exit 0 | _ -> exit 1