Redirect fileserver towards https

[benjamreis]

• Add location to Http.Request.Hdr
• Add response_redirect method to http-svr
• When GET is received by the fileserver and website-https-only is true:
  • if host is filled in the request, redirect towards the same URI but in HTTPS
  • if host is not present, reply with a forbidden as before

Solves: #4856

Signed-off-by: BenjiReis benjamin.reis@vates.fr

[psafont]

This looks good, waiting on Benjamin to post the results of manual testing

[benjamreis]

File "ocaml/xapi/fileserver.ml", line 97, characters 46-50:
97 |         let dest = Uri.(make ~scheme:"https" ~host ~path |> to_string) in
                                                   ^^^^
Error: This expression has type Uri.t -> string option
       but an expression was expected of type string

It seems to not take the host from the match above.

[psafont]

File "ocaml/xapi/fileserver.ml", line 97, characters 46-50:
97 |         let dest = Uri.(make ~scheme:"https" ~host ~path |> to_string) in
                                                   ^^^^
Error: This expression has type Uri.t -> string option
       but an expression was expected of type string

It seems to not take the host from the match above.

Because Uri is open, host is actually Uri.host, and path is actually Uri.path. A correct expression is:

let dest = Uri.make ~scheme:"https" ~host ~path () |> Uri.to_string

[benjamreis]

File "ocaml/xapi/fileserver.ml", line 97, characters 19-55:
97 |         let dest = Uri.make ~scheme:"https" ~host ~path |> Uri.to_string in
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Warning 5 [ignored-partial-application]: this function application is partial,
maybe some arguments are missing.
File "ocaml/xapi/fileserver.ml", line 97, characters [19](https://github.com/xapi-project/xen-api/actions/runs/3581868804/jobs/6025428280#step:11:20)-55:
97 |         let dest = Uri.make ~scheme:"https" ~host ~path |> Uri.to_string in
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Should I add a ignore around it?
Since other args are optionnal this shoulddn't be a problem right?

[lindig]

You need a unit () argument:

 utop # Uri.make;;
- : ?scheme:string ->
    ?userinfo:string ->
    ?host:string ->
    ?port:int ->
    ?path:string ->
    ?query:(string * string list) list -> ?fragment:string -> unit -> Uri.t

[benjamreis]

Thanks, it seems I need a bit more coffee this morning ^^'

[lindig]

"A function taking some optional arguments must also take at least one non-optional argument."

[benjamreis]

Okay so testing was successful :) This is good to go for us!