server: Listen on a unix domain socket

The server can now listen on a local unix domain socket when started
with:

    Ocsigen_server.start ~ports:[`File "./local.sock", 0]

This can allow testing.

`Socket_type.to_inet_addr` is removed as it's only used to later obtain
a string.

Author: Julow

src/extensions/revproxy.ml

@@ -105,7 +105,7 @@ let gen dir = function
                let h =
                  let forward =
                    let address =
-                     Unix.string_of_inet_addr
+                     Ocsigen_config.Socket_type.to_string
                        (Ocsigen_request.address request_info)
                    in
                    String.concat ", "

src/server/ocsigen_cohttp.ml

@@ -224,22 +224,24 @@ let service ?ssl ~address ~port ~connector () =
     | None -> `None
   in
   (* We create a specific context for Conduit and Cohttp. *)
-  Conduit_lwt_unix.init
-    ~src:(Ocsigen_config.Socket_type.to_string address)
-    ~tls_own_key ()
-  >>= fun conduit_ctx ->
+  let src =
+    match address with
+    | `File _ -> None
+    | _ -> Some (Ocsigen_config.Socket_type.to_string address)
+  in
+  Conduit_lwt_unix.init ?src ~tls_own_key () >>= fun conduit_ctx ->
   Lwt.return (Cohttp_lwt_unix.Net.init ~ctx:conduit_ctx ()) >>= fun ctx ->
   (* We catch the INET_ADDR of the server *)
   let callback =
-    let address = Ocsigen_config.Socket_type.to_inet_addr address
-    and ssl = match ssl with Some _ -> true | None -> false in
+    let ssl = match ssl with Some _ -> true | None -> false in
     handler ~ssl ~address ~port ~connector
   in
   let config = Cohttp_lwt_unix.Server.make ~conn_closed ~callback () in
   let mode =
-    match tls_own_key with
-    | `None -> `TCP (`Port port)
-    | `TLS (crt, key, pass) -> `OpenSSL (crt, key, pass, `Port port)
+    match address, tls_own_key with
+    | (`File _ as s), _ -> `Unix_domain_socket s
+    | _, `None -> `TCP (`Port port)
+    | _, `TLS (crt, key, pass) -> `OpenSSL (crt, key, pass, `Port port)
   in
   Cohttp_lwt_unix.Server.create ~stop ~ctx ~mode config >>= fun () ->
   Lwt.return (Lwt.wakeup stop_wakener ())

src/server/ocsigen_config.ml

@@ -28,17 +28,14 @@ type ssl_info =
   ; ssl_curve : string option }
 
 module Socket_type = struct
-  type t = [`All | `IPv4 of Unix.inet_addr | `IPv6 of Unix.inet_addr]
+  type t =
+    [`All | `IPv4 of Unix.inet_addr | `IPv6 of Unix.inet_addr | `File of string]
 
   let to_string = function
     | `All -> Unix.string_of_inet_addr Unix.inet_addr_any
     | `IPv4 u -> Unix.string_of_inet_addr u
     | `IPv6 u -> Unix.string_of_inet_addr u
-
-  let to_inet_addr = function
-    | `All -> Unix.inet_addr_any
-    | `IPv4 u -> u
-    | `IPv6 u -> u
+    | `File s -> s
 end
 
 type socket_type = Socket_type.t

src/server/ocsigen_config.mli

@@ -28,10 +28,10 @@ type ssl_info =
   ; ssl_curve : string option }
 
 module Socket_type : sig
-  type t = [`All | `IPv4 of Unix.inet_addr | `IPv6 of Unix.inet_addr]
+  type t =
+    [`All | `IPv4 of Unix.inet_addr | `IPv6 of Unix.inet_addr | `File of string]
 
   val to_string : t -> string
-  val to_inet_addr : t -> Unix.inet_addr
 end
 
 type socket_type = Socket_type.t

src/server/ocsigen_request.ml

@@ -49,7 +49,7 @@ let make_uri u =
   {u_uri; u_get_params; u_get_params_flat; u_path; u_path_string}
 
 type t =
-  { r_address : Unix.inet_addr
+  { r_address : Ocsigen_config.Socket_type.t
   ; r_port : int
   ; r_ssl : bool
   ; r_filenames : string list ref

src/server/ocsigen_request.mli

@@ -15,7 +15,7 @@ val make :
   -> ?original_full_path:string
   -> ?request_cache:Polytables.t
   -> ?cookies_override:string Ocsigen_cookie_map.Map_inner.t
-  -> address:Unix.inet_addr
+  -> address:Ocsigen_config.Socket_type.t
   -> port:int
   -> ssl:bool
   -> filenames:string list ref
@@ -42,7 +42,7 @@ val update :
 val to_cohttp : t -> Cohttp.Request.t
 val uri : t -> Uri.t
 val body : t -> Cohttp_lwt.Body.t
-val address : t -> Unix.inet_addr
+val address : t -> Ocsigen_config.Socket_type.t
 val host : t -> string option
 val meth : t -> Cohttp.Code.meth
 val port : t -> int