Merge pull request xapi-project#234 from Frezzle/ely-bugfix-CA-228780

CA-228780: Clear error message when PVS Proxy starts with no PVS servers

Author: robhoes

ocaml/idl/api_messages.ml

@@ -95,6 +95,7 @@ let v6_license_server_version_obsolete = addMessage "LICENSE_SERVER_VERSION_OBSO
 (* PVS alerts *)
 let pvs_proxy_no_cache_sr_available = addMessage "PVS_PROXY_NO_CACHE_SR_AVAILABLE" 3L (* No cache storage available for pvs site on the host *)
 let pvs_proxy_setup_failed = addMessage "PVS_PROXY_SETUP_FAILED" 3L (* Setting up pvs proxy rules or pvs proxy daemon initialisation failed internally *)
+let pvs_proxy_no_server_available = addMessage "PVS_PROXY_NO_SERVER_AVAILABLE" 3L (* No pvs server available for pvs site on host *)
 
 (* VMPP message types *)
 let vmpp_snapshot_lock_failed = addMessage "VMPP_SNAPSHOT_LOCK_FAILED" 3L (*'The snapshot phase is already executing for this protection policy. Please try again later'*)

ocaml/xapi/helpers.ml

@@ -1082,6 +1082,12 @@ let assert_using_vswitch ~__context =
   in
   if not using_vswitch then raise Api_errors.(Server_error (openvswitch_not_active, []))
 
+exception No_pvs_server_available
+
+let assert_pvs_servers_available ~__context ~pvs_site =
+  let pvs_servers = Db.PVS_site.get_servers ~__context ~self:pvs_site in
+  if pvs_servers = [] then raise No_pvs_server_available
+
 let assert_is_valid_ref ~__context ~name ~ref =
   if not (Db.is_valid_ref __context ref)
   then raise Api_errors.(Server_error (invalid_value, [

ocaml/xapi/pvs_proxy_control.ml

@@ -194,6 +194,7 @@ let start_proxy ~__context vif proxy =
   try
     Pool_features.assert_enabled ~__context ~f:Features.PVS_proxy;
     Helpers.assert_using_vswitch ~__context;
+    Helpers.assert_pvs_servers_available ~__context ~pvs_site:site;
 
     (* Create an interface and OVS port for the proxy *)
     let vifr = Db.VIF.get_record ~__context ~self:vif in
@@ -230,6 +231,17 @@ let start_proxy ~__context vif proxy =
         Helpers.call_api_functions ~__context (fun rpc session_id ->
             ignore(Client.Client.Message.create ~rpc ~session_id ~name ~priority ~cls:`PVS_proxy ~obj_uuid:proxy_uuid ~body));
         "unable to connect to PVS proxy daemon"
+      | Helpers.No_pvs_server_available ->
+        let proxy_uuid = Db.PVS_proxy.get_uuid ~__context ~self:proxy in
+        let vif_uuid = Db.VIF.get_uuid ~__context ~self:vif in
+        let site_name_label = Db.PVS_site.get_name_label ~__context ~self:(Db.PVS_proxy.get_site ~__context ~self:proxy) in
+        let host_name_label = Db.Host.get_name_label ~__context ~self:(Helpers.get_localhost ~__context) in
+        let body = Printf.sprintf "Unable to setup PVS-proxy %s for VIF %s: no PVS-server found on PVS-site %s for host %s."
+            proxy_uuid vif_uuid site_name_label host_name_label in
+        let (name, priority) = Api_messages.pvs_proxy_no_server_available in
+        Helpers.call_api_functions ~__context (fun rpc session_id ->
+            ignore(Client.Client.Message.create ~rpc ~session_id ~name ~priority ~cls:`PVS_proxy ~obj_uuid:proxy_uuid ~body));
+        "no PVS server available"
       | Api_errors.Server_error (code, args) when
           code = Api_errors.license_restriction
           && args = [Features.(name_of_feature PVS_proxy)] ->