Add file-upload support to xe host-call-plugin

To pass file content to a plugin, vm-call-plugin supports passing the
content of a client-side file as a parameter. This is missing for
host-call-plugin - this patch adds it. Otherwise is difficult to pass
anything beyond a short string to a plugin.

Signed-off-by: Christian Lindig <[email protected]>

Author: Christian Lindig

ocaml/xapi-cli-server/cli_frontend.ml

@@ -958,8 +958,9 @@ let rec cmdtable_data : (string * cmd_spec) list =
       ; optn= ["args:"]
       ; help=
           "Calls the function within the plugin on the given host with \
-           optional arguments."
-      ; implementation= No_fd Cli_operations.host_call_plugin
+           optional arguments. The syntax args:key:file=/path/file.ext passes \
+           the content of /path/file.ext under key to the plugin."
+      ; implementation= With_fd Cli_operations.host_call_plugin
       ; flags= []
       }
     )

ocaml/xapi-cli-server/cli_operations.ml

@@ -6907,12 +6907,27 @@ let host_set_hostname_live _printer rpc session_id params =
   let hostname = List.assoc "host-name" params in
   Client.Host.set_hostname_live ~rpc ~session_id ~host ~hostname
 
-let host_call_plugin printer rpc session_id params =
+let host_call_plugin fd printer rpc session_id params =
   let host_uuid = List.assoc "host-uuid" params in
   let host = Client.Host.get_by_uuid ~rpc ~session_id ~uuid:host_uuid in
   let plugin = List.assoc "plugin" params in
   let fn = List.assoc "fn" params in
   let args = read_map_params "args" params in
+  let convert ((k, v) as p) =
+    match Astring.String.cut ~sep:":" k with
+    | Some (key, "file") -> (
+      match get_client_file fd v with
+      | Some s ->
+          (key, s)
+      | None ->
+          marshal fd
+            (Command (PrintStderr (Printf.sprintf "Failed to read file %s\n" v))) ;
+          raise (ExitWithError 1)
+    )
+    | _ ->
+        p
+  in
+  let args = List.map convert args in
   let result =
     Client.Host.call_plugin ~rpc ~session_id ~host ~plugin ~fn ~args
   in