albatross/stats/vmm_stats.ml
2018-10-26 21:29:59 +02:00

206 lines
6.9 KiB
OCaml

(* (c) 2017, 2018 Hannes Mehnert, all rights reserved *)
open Astring
open Rresult.R.Infix
open Vmm_core
external sysctl_rusage : int -> Stats.rusage = "vmmanage_sysctl_rusage"
external sysctl_ifcount : unit -> int = "vmmanage_sysctl_ifcount"
external sysctl_ifdata : int -> Stats.ifdata = "vmmanage_sysctl_ifdata"
type vmctx
external vmmapi_open : string -> vmctx = "vmmanage_vmmapi_open"
external vmmapi_close : vmctx -> unit = "vmmanage_vmmapi_close"
external vmmapi_statnames : vmctx -> string list = "vmmanage_vmmapi_statnames"
external vmmapi_stats : vmctx -> int64 list = "vmmanage_vmmapi_stats"
let my_version = `AV2
let descr = ref []
type 'a t = {
pid_nic : ((vmctx, int) result * (int * string) list) IM.t ;
vmid_pid : int Vmm_trie.t ;
name_sockets : 'a Vmm_trie.t ;
}
let pp_strings pp taps = Fmt.(list ~sep:(unit ",@ ") string) pp taps
let empty () =
{ pid_nic = IM.empty ; vmid_pid = Vmm_trie.empty ; name_sockets = Vmm_trie.empty }
let remove_entry t name =
let name_sockets = Vmm_trie.remove name t.name_sockets in
{ t with name_sockets }
let rec wrap f arg =
try Some (f arg) with
| Unix.Unix_error (Unix.EINTR, _, _) -> wrap f arg
| e ->
Logs.err (fun m -> m "exception %s" (Printexc.to_string e)) ;
None
let fill_descr ctx =
match !descr with
| [] ->
begin match wrap vmmapi_statnames ctx with
| None ->
Logs.err (fun m -> m "vmmapi_statnames failed, shouldn't happen") ;
()
| Some d ->
Logs.debug (fun m -> m "descr are %a" pp_strings d) ;
descr := d
end
| ds -> Logs.debug (fun m -> m "%d descr are already present" (List.length ds))
let open_vmmapi ?(retries = 4) pid =
let name = "solo5-" ^ string_of_int pid in
if retries = 0 then begin
Logs.debug (fun m -> m "(ignored 0) vmmapi_open failed for %d" pid) ;
Error 0
end else
match wrap vmmapi_open name with
| None ->
let left = max 0 (pred retries) in
Logs.warn (fun m -> m "(ignored, %d attempts left) vmmapi_open failed for %d" left pid) ;
Error left
| Some vmctx ->
Logs.info (fun m -> m "vmmapi_open succeeded for %d" pid) ;
fill_descr vmctx ;
Ok vmctx
let try_open_vmmapi pid_nic =
IM.fold (fun pid (vmctx, nics) fresh ->
let vmctx =
match vmctx with
| Ok vmctx -> Ok vmctx
| Error retries -> open_vmmapi ~retries pid
in
IM.add pid (vmctx, nics) fresh)
pid_nic IM.empty
let gather pid vmctx nics =
wrap sysctl_rusage pid,
(match vmctx with
| Error _ -> None
| Ok vmctx -> wrap vmmapi_stats vmctx),
List.fold_left (fun ifd (nic, nname) ->
match wrap sysctl_ifdata nic with
| None ->
Logs.warn (fun m -> m "failed to get ifdata for %s" nname) ;
ifd
| Some data -> data::ifd)
[] nics
let tick t =
let pid_nic = try_open_vmmapi t.pid_nic in
let t' = { t with pid_nic } in
let outs =
List.fold_left (fun out (vmid, pid) ->
let listeners = Vmm_trie.collect vmid t'.name_sockets in
match listeners with
| [] -> Logs.warn (fun m -> m "nobody is listening") ; out
| xs -> match IM.find_opt pid t.pid_nic with
| None -> Logs.warn (fun m -> m "couldn't find nics of %d" pid) ; out
| Some (vmctx, nics) ->
let ru, vmm, ifd = gather pid vmctx nics in
match ru with
| None -> Logs.err (fun m -> m "failed to get rusage for %d" pid) ; out
| Some ru' ->
let stats =
let vmm' = match vmm with None -> None | Some xs -> Some (List.combine !descr xs) in
ru', vmm', ifd
in
List.fold_left (fun out (id, socket) ->
match Vmm_core.drop_super ~super:id ~sub:vmid with
| None -> Logs.err (fun m -> m "couldn't drop super %a from sub %a" Vmm_core.pp_id id Vmm_core.pp_id vmid) ; out
| Some real_id ->
let header = Vmm_commands.{ version = my_version ; sequence = 0L ; id = real_id } in
((socket, vmid, (header, `Data (`Stats_data stats))) :: out))
out xs)
[] (Vmm_trie.all t'.vmid_pid)
in
(t', outs)
let add_pid t vmid pid nics =
match wrap sysctl_ifcount () with
| None ->
Logs.err (fun m -> m "sysctl ifcount failed for %d %a" pid pp_strings nics) ;
Error (`Msg "sysctl ifcount failed")
| Some max_nic ->
let rec go cnt acc id =
if id > 0 && cnt > 0 then
match wrap sysctl_ifdata id with
| Some ifd when List.mem ifd.Vmm_core.Stats.name nics ->
go (pred cnt) ((id, ifd.Vmm_core.Stats.name) :: acc) (pred id)
| _ -> go cnt acc (pred id)
else
List.rev acc
in
Ok (go (List.length nics) [] max_nic) >>= fun nic_ids ->
let vmctx = open_vmmapi pid in
Logs.info (fun m -> m "adding %d %a with vmctx %b" pid pp_strings nics
(match vmctx with Error _ -> false | Ok _ -> true)) ;
let pid_nic = IM.add pid (vmctx, nic_ids) t.pid_nic
and vmid_pid, ret = Vmm_trie.insert vmid pid t.vmid_pid
in
assert (ret = None) ;
Ok { t with pid_nic ; vmid_pid }
let remove_vmid t vmid =
Logs.info (fun m -> m "removing vmid %a" Vmm_core.pp_id vmid) ;
match Vmm_trie.find vmid t.vmid_pid with
| None -> Logs.warn (fun m -> m "no pid found for %a" Vmm_core.pp_id vmid) ; t
| Some pid ->
Logs.info (fun m -> m "removing pid %d" pid) ;
(try
match IM.find pid t.pid_nic with
| Ok vmctx, _ -> ignore (wrap vmmapi_close vmctx)
| Error _, _ -> ()
with
_ -> ()) ;
let pid_nic = IM.remove pid t.pid_nic
and vmid_pid = Vmm_trie.remove vmid t.vmid_pid
in
{ t with pid_nic ; vmid_pid }
let remove_vmids t vmids =
List.fold_left remove_vmid t vmids
let handle t socket (header, wire) =
let r =
if not (Vmm_commands.version_eq my_version header.Vmm_commands.version) then
Error (`Msg "cannot handle version")
else
match wire with
| `Command (`Stats_cmd cmd) ->
begin
let id = header.Vmm_commands.id in
match cmd with
| `Stats_add (pid, taps) ->
add_pid t id pid taps >>= fun t ->
Ok (t, `Add id, None, Some "added")
| `Stats_remove ->
let t = remove_vmid t id in
Ok (t, `Remove id, None, Some "removed")
| `Stats_subscribe ->
let name_sockets, close = Vmm_trie.insert id socket t.name_sockets in
Ok ({ t with name_sockets }, `None, close, Some "subscribed")
end
| _ ->
Logs.warn (fun m -> m "ignoring %a" Vmm_commands.pp_wire (header, wire)) ;
Ok (t, `None, None, None)
in
match r with
| Ok (t, action, close, out) ->
let out = match out with
| None -> None
| Some str -> Some (header, `Success (`String str))
in
t, action, close, out
| Error (`Msg msg) ->
Logs.err (fun m -> m "error while processing %s" msg) ;
t, `None, None, Some (header, `Failure msg)