CP-44105: Adjust Net.reset_state for pool.eject_self (#6481)

As pool.eject_self calls interface-rename script to rename the network
interfaces, this behaviour should be done compatibly.
So, move the interface-rename to networkd with compatibility check.
When reset networkd state
legacy: use interface-rename script to sort and rename
new: use networkd network_device_order with initial empty order to sort

Author: changlei-li

ocaml/networkd/bin/network_server.ml

@@ -136,8 +136,21 @@ let sync_state () =
   write_config ()
 
 let reset_state () =
-  let interface_order, _ = sort Network_config.initial_interface_order in
-  config := Network_config.read_management_conf interface_order
+  let reset_order =
+    match !config.interface_order with
+    | Some _ ->
+        (* Use empty config interface_order to sort to generate fresh-install
+           state for currently-installed hardware *)
+        sort Network_config.empty_config.interface_order |> fst
+    | None ->
+        ignore
+          (Forkhelpers.execute_command_get_output
+             "/etc/sysconfig/network-scripts/interface-rename.py"
+             ["--reset-to-install"]
+          ) ;
+        None
+  in
+  config := Network_config.read_management_conf reset_order
 
 let set_gateway_interface _dbg name =
   (* Remove dhclient conf (if any) for the old and new gateway interfaces.

ocaml/xapi/xapi_pif.ml

@@ -116,7 +116,7 @@ let refresh_internal ~__context ~interface_tables ~self =
           info "PIF: device name changed from %s to %s" original_name name ;
         name
     | None -> (
-        (* This clause should be unlike to happen, if enter this, check the if
+        (* This clause should be unlikely to happen, if enter this, check the if
            we can get mac from networkd. If yes there may be a bug *)
         warn "PIF %s: no device found for position %d" original_name position ;
         try

ocaml/xapi/xapi_pool.ml

@@ -2088,7 +2088,6 @@ let eject_self ~__context ~host =
         configuration_file
     in
     write_first_boot_management_interface_configuration_file () ;
-    Net.reset_state () ;
     Xapi_inventory.update Xapi_inventory._current_interfaces "" ;
     (* Destroy my control domains, since you can't do this from the API [operation not allowed] *)
     ( try
@@ -2148,15 +2147,10 @@ let eject_self ~__context ~host =
               (!Xapi_globs.remote_db_conf_fragment_path ^ ".bak")
           )
           () ;
-        (* Reset the domain 0 network interface naming configuration
-           			 * back to a fresh-install state for the currently-installed
-           			 * hardware.
-        *)
-        ignore
-          (Forkhelpers.execute_command_get_output
-             "/etc/sysconfig/network-scripts/interface-rename.py"
-             ["--reset-to-install"]
-          )
+        (* Reset the domain 0 network interface order back to a fresh-install
+         * state for the currently-installed hardware and reset networkd config.
+         *)
+        Net.reset_state ()
       )
       (fun () -> Xapi_fuse.light_fuse_and_reboot_after_eject ()) ;
     Xapi_hooks.pool_eject_hook ~__context