CA-393199: Disable external auth should clean pbis cache

The domain information is cached by PBIS. Such cache can
help to accelerate query of domain information.

However, the cache data should be cleaned during disable
external auth to make sure
- release cache as the domain is left
- rejoin domain refresh all the domain information

Signed-off-by: Lin Liu <[email protected]>

ocaml/xapi/extauth_plugin_ADpbis.ml

@@ -1052,6 +1052,14 @@ module AuthADlw : Auth_signature.AUTH_MODULE = struct
   let on_disable config_params =
     (* but in the ldap plugin, we should 'leave the AD/kerberos domain', i.e. we should *)
     (* (1) remove the machine account from the kerberos realm, (2) remove the keytab locally *)
+
+    (* Clean pbis cache as we are disabling external auth and will leave domain *)
+    ( try pbis_common "/opt/pbis/bin/ad-cache" ["--delete-all"] |> ignore
+      with e ->
+        Printexc.to_string e
+        |> debug "Got error cleaning pbis cache, ignore the error %s"
+    ) ;
+
     let pbis_failure =
       try
         ( if