Merge pull request xapi-project#5435 from snwoods/private/stevenwo/CP…

…-46155

CP-46155: Call SM scripts via observer.py when SM observer is enabled

ocaml/forkexecd/lib/forkhelpers.ml

@@ -184,7 +184,7 @@ let safe_close_and_exec ?env stdin stdout stderr
         List.fold_left maybe_add_id_to_fd_map dest_named_fds predefined_fds
       in
 
-      let env = match env with Some e -> e | None -> default_path_env_pair in
+      let env = Option.value ~default:default_path_env_pair env in
       let syslog_stdout =
         match syslog_stdout with
         | NoSyslogging ->

ocaml/xapi-idl/lib/debuginfo.ml

@@ -66,10 +66,9 @@ let with_dbg ?(with_thread = false) ~module_name ~name ~dbg f =
   | false ->
       f_with_trace ()
 
-let span_context_of_di di =
-  Option.map (fun span -> Tracing.Span.get_context span) di.tracing
-
 let traceparent_of_dbg dbg =
-  of_string dbg
-  |> span_context_of_di
-  |> Option.map Tracing.SpanContext.trace_id_of_span_context
+  match String.split_on_char separator dbg with
+  | [_; traceparent] ->
+      Some traceparent
+  | _ ->
+      None

ocaml/xapi/sm_exec.ml

@@ -336,20 +336,19 @@ let exec_xmlrpc ~dbg ?context:_ ?(needs_session = true) (driver : string)
           (* Logging call.cmd is safe, but call.args could contain a password. *)
           try
             E.debug "smapiv2=>smapiv1 [label=\"%s\"];" call.cmd ;
+            let args = [Xml.to_string xml] in
             let output, stderr =
-              let env =
+              let env, exe, args =
                 match Xapi_observer_components.is_smapi_enabled () with
                 | false ->
-                    None
+                    (None, exe, args)
                 | true ->
                     let traceparent = Debuginfo.traceparent_of_dbg dbg in
-                    Some
-                      (Xapi_observer_components.env_vars_of_component
-                         ~component:Xapi_observer_components.SMApi ~traceparent
-                      )
+                    Xapi_observer_components.env_exe_args_of
+                      ~component:Xapi_observer_components.SMApi ~traceparent
+                      ~exe ~args
               in
-              Forkhelpers.execute_command_get_output ?env exe
-                [Xml.to_string xml]
+              Forkhelpers.execute_command_get_output ?env exe args
             in
             try (Xml.parse_string output, stderr)
             with e ->

ocaml/xapi/xapi_globs.ml

@@ -1017,6 +1017,8 @@ let observer_endpoint_http_enabled = ref false
 
 let observer_endpoint_https_enabled = ref false
 
+let python3_path = ref "/usr/bin/python3"
+
 let xapi_globs_spec =
   [
     ( "master_connection_reset_timeout"

ocaml/xapi/xapi_observer_components.ml

@@ -84,18 +84,26 @@ let ( // ) = Filename.concat
 let dir_name_of_component component =
   Xapi_globs.observer_config_dir // to_string component // "enabled"
 
-let env_vars_of_component ~component ~traceparent =
+let env_exe_args_of ~component ~traceparent ~exe ~args =
   let dir_name_value = Filename.quote (dir_name_of_component component) in
-  Array.concat
-    [
-      Forkhelpers.default_path_env_pair
-    ; Env_record.to_string_array
-        ([Env_record.pair ("OBSERVER_CONFIG_DIR", dir_name_value)]
-        @
-        match traceparent with
-        | None ->
-            []
-        | Some traceparent ->
-            [Env_record.pair ("TRACEPARENT", traceparent)]
-        )
-    ]
+  let env_vars =
+    Array.concat
+      [
+        Forkhelpers.default_path_env_pair
+      ; Env_record.to_string_array
+          ([
+             Env_record.pair ("OBSERVER_CONFIG_DIR", dir_name_value)
+           ; Env_record.pair ("PYTHONPATH", Filename.dirname exe)
+           ]
+          @
+          match traceparent with
+          | None ->
+              []
+          | Some traceparent ->
+              [Env_record.pair ("TRACEPARENT", traceparent)]
+          )
+      ]
+  in
+  let args = "-m" :: "observer" :: exe :: args in
+  let new_exe = !Xapi_globs.python3_path in
+  (Some env_vars, new_exe, args)

ocaml/xapi/xapi_observer_components.mli

@@ -12,8 +12,8 @@
  * GNU Lesser General Public License for more details.
  *)
 
-(** Xapi_observer_components module contains generic operations on components 
-  * instrumented with tracing. These operations act on components independently 
+(** Xapi_observer_components module contains generic operations on components
+  * instrumented with tracing. These operations act on components independently
   * of observers.
   *)
 
@@ -39,13 +39,13 @@ val startup_components : unit -> t list
   *)
 
 val assert_valid_components : string list -> unit
-(** Checks if a given list is made of only string equivalents of supported 
+(** Checks if a given list is made of only string equivalents of supported
   * components.
   * Raises Server_error if at least one of the elements is invalid.
   *)
 
 val observed_components_of : t list -> t list
-(** Transforms a list of components to a list of components that are expected 
+(** Transforms a list of components to a list of components that are expected
   * to be observed. If the list is empty we expect all startup components.
   *)
 
@@ -58,12 +58,16 @@ val is_smapi_enabled : unit -> bool
   *)
 
 val dir_name_of_component : t -> string
-(** Returns the directory path that python scripts check to see if a component 
+(** Returns the directory path that python scripts check to see if a component
   * is enabled.
   *)
 
-val env_vars_of_component :
-  component:t -> traceparent:string option -> string array
-(** Returns an array of environment viariables used by python scripts to 
-  *  configure the python observers.  
+val env_exe_args_of :
+     component:t
+  -> traceparent:string option
+  -> exe:string
+  -> args:string list
+  -> string array option * string * string list
+(** Returns an array option of environment variables and the modified exe and
+  *  args used by python scripts to configure the python observers.
   *)