Mimic_happy_eyeballs.Make
The functor used by the MirageOS to prepare the Mimic.ctx
from an already allocated happy_eyeballs
resource which is able to allocate a TCP/IP connection from a destination regardless the target chosen by the user.
include S with type t = Happy_eyeballs.t and type flow = Stack.TCP.flow
val happy_eyeballs : t Mimic.value
val resolve :
t ->
?aaaa_timeout:int64 ->
?connect_delay:int64 ->
?connect_timeout:int64 ->
?resolve_timeout:int64 ->
?resolve_retries:int ->
string ->
int list ->
((Ipaddr.t * int) * flow, [> `Msg of string ]) Stdlib.result Lwt.t
resolve happy_eyeballs domain_name ports
tries to connect the user with the given endpoint. The domain-name can be an IP address or a real domain-name. resolve
tries to resolve via a DNS request the given domain_name
if it's a real domain-name and it tries to initiate a TCP/IP connection with the destination.
If it's a success, it returns the resource and the user is able to read
or write
via this resource.
connect happy_eyeballs
returns a Mimic.ctx
which contains an happy_eyeballs
value which can be used and re-used by some others devices which want to resolve a domain-name.
More concretely, the user is able to describe a sub-process to allocate a flow
from some Mimic's values:
(* main.ml, generated by the mirage tool *)
include Make (Stack) (Dns) (Happy_eyeballs)
let domain_name : string Mimic.value =
Mimic.make ~name:"domain-name"
let ctx happy_eyeballs_v =
let open Lwt.Infix in
let k0 happy_eyeballs domain_name =
resolve happy_eyeballs domain_name [ 80 ] >>= function
| Ok (_, flow) -> Lwt.return_some flow
| Error _ -> Lwt.return_none in
connect happy_eyeballs_v >|=
Mimic.fold edn Mimic.Fun.[ req happy_eyeballs; req domain_name ]
~k:k0
(* unikernel.ml *)
let run ~ctx = Mimic.resolve ctx >>= function
| Ok flow -> (* ... *)
| Error (`Msg err) -> failwith err