Exception raised in custom environments - Exception not catch, raised by "input_line", App.ml, l. 106 #288
Description
Hi.
I used Opium with OpenAPI addon, to make a prototype locally, in normal Fedora/Linux environment, that works wonderfully, but when deployed on targeted system, binary crashed because End_of_file exception.
After some investigations, it comes from App.ml, l. 106.
let system_cores =
match Sys.unix with
| false ->
(* TODO: detect number of cores on Windows *)
1
| true ->
let ic = Unix.open_process_in "getconf _NPROCESSORS_ONLN" in
let cores = int_of_string (input_line ic) in
ignore (Unix.close_process_in ic);
cores
;;Opium is deployed in a minimalist chroot, on a custom build Linux environment with no rights.
It means, that there is no getconf (input_line raised End_of_file),
and no shell accessible for any binaries for security reasons (so Unix.open_process_in does not work either, even with getconf accessible).
I would propose an evolution, or at least a "normal" patch that would consist in catching ALL unexposed, raised exception.
In this case, I would propose.
let system_cores =
match Sys.unix with
| false ->
(* TODO: detect number of cores on Windows *)
1
| true -> begin try
let ic = Unix.open_process_in "getconf _NPROCESSORS_ONLN" in
let cores = int_of_string (input_line ic) in
ignore (Unix.close_process_in ic);
cores
with End_of_file ->
(* MAYBE: Warn user that you can't determine how many cores are available *)
1
end
;;Or maybe add a ?(available_cores = 1) parameter in server options that would let the user define how many cores Webserver should use.
But the only solution we found is using a proxy of Opium just to patch this, which is not a valid long term solution ;D.
So hopping it deserves a patch and a 0.21.0.
By wishing you a good day,
Matthieu GOSSET