XSI-2093: CA-422229: Host should not register all IPs to DNS server (#6811)

Fixes: cba2f1d
During fix the localhost name issue, An problem was found Hosts in a
pool can not resovle each other with static IP Thus, an enhancement is
applied to push host name and IPs to DNS, This pushed all IPs of the
host into DNS server, including the storage interface.

This commit just revert the DNS change.
Regarding the resovle issue with static IP, it better goes to somewhere
else like network event hook, or system deamon, if we do care about it
and want a fix.

Author: liulinC

ocaml/xapi/extauth_plugin_ADwinbind.ml

@@ -1238,59 +1238,6 @@ module ConfigHosts = struct
     |> write_string_to_file path
 end
 
-module DNSSync = struct
-  let task_name = "Sync hostname with DNS"
-
-  type t = Register | Unregister
-
-  let handle op hostname netbios_name domain =
-    (* By default, hostname should equal to netbios_name, just register it to DNS server*)
-    try
-      let ops =
-        match op with Register -> "register" | Unregister -> "unregister"
-      in
-      let netbios_fqdn = Printf.sprintf "%s.%s" netbios_name domain in
-      let args = ["ads"; "dns"] @ [ops] @ ["--machine-pass"] in
-      Helpers.call_script net_cmd (args @ [netbios_fqdn]) |> ignore ;
-      if hostname <> netbios_name then
-        let hostname_fqdn = Printf.sprintf "%s.%s" hostname domain in
-        (* netbios_name is compressed, op on extra hostname *)
-        Helpers.call_script net_cmd (args @ [hostname_fqdn]) |> ignore
-    with e ->
-      debug "Register/unregister with DNS failed %s" (ExnHelper.string_of_exn e)
-
-  let register hostname netbios_name domain =
-    handle Register hostname netbios_name domain
-
-  let unregister hostname netbios_name domain =
-    handle Unregister hostname netbios_name domain
-
-  let sync () =
-    Server_helpers.exec_with_new_task "sync hostname with DNS"
-    @@ fun __context ->
-    let host = Helpers.get_localhost ~__context in
-    let service_name =
-      Db.Host.get_external_auth_service_name ~__context ~self:host
-    in
-    let netbios_name =
-      Db.Host.get_external_auth_configuration ~__context ~self:host
-      |> fun config -> List.assoc_opt "netbios_name" config
-    in
-    let hostname = Db.Host.get_hostname ~__context ~self:host in
-    match netbios_name with
-    | Some netbios ->
-        register hostname netbios service_name
-    | None ->
-        debug "Netbios name is none, skip sync hostname to DNS"
-
-  let trigger_sync ~start =
-    debug "Trigger task: %s" task_name ;
-    Scheduler.add_to_queue task_name
-      (Scheduler.Periodic !Xapi_globs.winbind_dns_sync_interval) start sync
-
-  let stop_sync () = Scheduler.remove_from_queue task_name
-end
-
 let build_netbios_name ~config_params =
   let key = "netbios-name" in
   match List.assoc_opt key config_params with
@@ -1657,7 +1604,6 @@ module AuthADWinbind : Auth_signature.AUTH_MODULE = struct
           [get_localhost_name ()]
       in
       (* Trigger right now *)
-      DNSSync.trigger_sync ~start:0. ;
       Winbind.set_machine_account_encryption_type netbios_name ;
       debug "Succeed to join domain %s" service_name
     with
@@ -1697,12 +1643,9 @@ module AuthADWinbind : Auth_signature.AUTH_MODULE = struct
     let user = List.assoc_opt "user" config_params in
     let pass = List.assoc_opt "pass" config_params in
     let {service_name; netbios_name; _} = get_domain_info_from_db () in
-    DNSSync.stop_sync () ;
     ( match netbios_name with
     | Some netbios ->
-        ConfigHosts.leave ~domain:service_name ~name:netbios ;
-        let hostname = get_localhost_name () in
-        DNSSync.unregister hostname netbios service_name
+        ConfigHosts.leave ~domain:service_name ~name:netbios
     | _ ->
         ()
     ) ;
@@ -1731,7 +1674,6 @@ module AuthADWinbind : Auth_signature.AUTH_MODULE = struct
     RotateMachinePassword.trigger_rotate ~start:5. ;
     Winbind.check_ready_to_serve ~timeout:300. ;
     Winbind.flush_cache () ;
-    DNSSync.trigger_sync ~start:5. ;
 
     let {service_name; netbios_name; _} = get_domain_info_from_db () in
     match netbios_name with

ocaml/xapi/xapi_globs.ml

@@ -1051,8 +1051,6 @@ let winbind_cache_time = ref 60
 
 let winbind_machine_pwd_timeout = ref (2. *. 7. *. 24. *. 3600.)
 
-let winbind_dns_sync_interval = ref 3600.
-
 let winbind_update_closest_kdc_interval = ref (3600. *. 22.)
 (* every 22 hours *)
 
@@ -1270,7 +1268,6 @@ let xapi_globs_spec =
   ; ("winbind_debug_level", Int winbind_debug_level)
   ; ("winbind_cache_time", Int winbind_cache_time)
   ; ("winbind_machine_pwd_timeout", Float winbind_machine_pwd_timeout)
-  ; ("winbind_dns_sync_interval", Float winbind_dns_sync_interval)
   ; ( "winbind_update_closest_kdc_interval"
     , Float winbind_update_closest_kdc_interval
     )