tracing: observe modes and other tracing improvements.

ocaml/libs/tracing/dune

@@ -24,3 +24,8 @@
   zstd)
  (preprocess
   (pps ppx_deriving_rpc)))
+
+(test
+ (name test_tracing)
+ (modules test_tracing)
+ (libraries tracing alcotest uuid))

ocaml/libs/tracing/test_tracing.ml

@@ -0,0 +1,216 @@
+module D = Debug.Make (struct let name = "test_tracing" end)
+
+let attr_to_string (key, value) = Printf.sprintf "%s:%s" key value
+
+let attr_compare attr1 attr2 =
+  String.compare (attr_to_string attr1) (attr_to_string attr2)
+
+let attr_testable =
+  let pp = Fmt.of_to_string attr_to_string in
+
+  Alcotest.testable pp (fun (k1, v1) (k2, v2) -> k1 = k2 && v1 = v2)
+
+let assert_provider_enabled provider flag =
+  Alcotest.(check bool)
+    "Check state of trace provider" flag
+    (Tracing.TracerProvider.get_enabled provider)
+
+let assert_provider_attrs provider attributes =
+  Alcotest.(check (slist attr_testable attr_compare))
+    "Check attributes of trace provider" attributes
+    (Tracing.TracerProvider.get_attributes provider)
+
+let assert_provider_name_label provider label =
+  Alcotest.(check string)
+    "Check label of trace provider" label
+    (Tracing.TracerProvider.get_name_label provider)
+
+let assert_provider_endpoints provider endpoints =
+  Alcotest.(check (list string))
+    "Check endpoints of trace provider" endpoints
+    (provider
+    |> Tracing.TracerProvider.get_endpoints
+    |> List.map Tracing.endpoint_to_string
+    )
+
+let assert_observe_mode flag =
+  Alcotest.(check bool)
+    "Check observe mode of library" flag (Tracing.get_observe ())
+
+let uuid1, uuid2, uuid3 =
+  Uuidx.(to_string (make ()), to_string (make ()), to_string (make ()))
+
+let http_endpoint = "http://example.com:9411/api/v2/spans"
+
+let with_observe_mode_check flag f = f () ; assert_observe_mode flag
+
+let get_provider name_label =
+  let providers =
+    Tracing.TracerProvider.get_tracer_providers ()
+    |> List.filter (fun provider ->
+           String.equal
+             (Tracing.TracerProvider.get_name_label provider)
+             name_label
+       )
+  in
+  match providers with
+  | [provider] ->
+      provider
+  | _ ->
+      Alcotest.failf "expected only one provider"
+
+let create_with (enabled, attributes, endpoints, name_label, uuid) =
+  let () =
+    Tracing.TracerProvider.create ~enabled ~attributes ~endpoints ~name_label
+      ~uuid
+  in
+  get_provider name_label
+
+let test_destroy_all_providers uuids =
+  let () = List.iter (fun uuid -> Tracing.TracerProvider.destroy ~uuid) uuids in
+  assert_observe_mode false
+
+let test_create_and_destroy () =
+  let test_create_with (enabled, attributes, endpoints, name_label, uuid) =
+    let provider =
+      create_with (enabled, attributes, endpoints, name_label, uuid)
+    in
+    assert_provider_enabled provider enabled ;
+    assert_provider_attrs provider attributes ;
+    assert_provider_endpoints provider endpoints ;
+    assert_provider_name_label provider name_label
+  in
+
+  let uuids = [uuid1; uuid2; uuid3] in
+
+  let provider_confs_enable_observe =
+    [
+      ( true
+      , [("enabled", "true")]
+      , [Tracing.bugtool_name]
+      , "dummy_test_provider_1"
+      , uuid1
+      )
+    ; ( false
+      , []
+      , [Tracing.bugtool_name; http_endpoint]
+      , "dummy_test_provider_2"
+      , uuid2
+      )
+    ; ( false
+      , [("enabled", "false"); ("is_test", "true")]
+      , [http_endpoint]
+      , "dummy_test_provider_3"
+      , uuid3
+      )
+    ]
+  in
+  let provider_confs_disable_observe =
+    [
+      ( false
+      , [("enabled", "false")]
+      , [Tracing.bugtool_name]
+      , "dummy_test_provider_1"
+      , uuid1
+      )
+    ; ( false
+      , []
+      , [Tracing.bugtool_name; http_endpoint]
+      , "dummy_test_provider_2"
+      , uuid2
+      )
+    ; ( false
+      , [("enabled", "false"); ("is_test", "true")]
+      , [http_endpoint]
+      , "dummy_test_provider_3"
+      , uuid3
+      )
+    ]
+  in
+
+  (* We start with no tracer providers, therefore, we expect the observe mode to
+     be disbled. *)
+  assert_observe_mode false ;
+
+  let test_provider_conf conf expected_mode_state =
+    with_observe_mode_check expected_mode_state (fun () ->
+        List.iter test_create_with conf
+    ) ;
+    test_destroy_all_providers uuids ;
+    with_observe_mode_check expected_mode_state (fun () ->
+        List.iter test_create_with (List.rev conf)
+    ) ;
+    test_destroy_all_providers uuids
+  in
+
+  test_provider_conf provider_confs_enable_observe true ;
+  test_provider_conf provider_confs_disable_observe false
+
+let test_set_tracer_provider () =
+  let test_set_with provider (enabled, attributes, endpoints, uuid) =
+    Tracing.TracerProvider.set ~enabled ~attributes ~endpoints ~uuid () ;
+    let updated_provider =
+      provider |> Tracing.TracerProvider.get_name_label |> get_provider
+    in
+    assert_provider_enabled updated_provider enabled ;
+    assert_provider_attrs updated_provider attributes ;
+    assert_provider_endpoints updated_provider endpoints
+  in
+
+  let provider1 =
+    create_with
+      (false, [], [Tracing.bugtool_name], "dummy_test_provider_1", uuid1)
+  in
+
+  let provider2 =
+    create_with
+      (false, [], [Tracing.bugtool_name], "dummy_test_provider_2", uuid2)
+  in
+
+  let new_provider1_confs =
+    ( ( true
+      , [("test_set", "true")]
+      , [Tracing.bugtool_name; http_endpoint]
+      , uuid1
+      )
+    , (false, [], [Tracing.bugtool_name; http_endpoint], uuid1)
+    )
+  in
+
+  let new_provider2_confs =
+    ( ( true
+      , [("test_set", "true"); ("dummy_key", "dummy_value")]
+      , [Tracing.bugtool_name; http_endpoint]
+      , uuid2
+      )
+    , (false, [], [Tracing.bugtool_name; http_endpoint], uuid2)
+    )
+  in
+
+  assert_observe_mode false ;
+
+  with_observe_mode_check true (fun () ->
+      test_set_with provider1 (fst new_provider1_confs)
+  ) ;
+
+  with_observe_mode_check true (fun () ->
+      test_set_with provider2 (fst new_provider2_confs)
+  ) ;
+  with_observe_mode_check true (fun () ->
+      test_set_with provider1 (snd new_provider1_confs)
+  ) ;
+
+  with_observe_mode_check false (fun () ->
+      test_set_with provider2 (snd new_provider2_confs)
+  ) ;
+
+  test_destroy_all_providers [uuid1; uuid2] ;
+  assert_observe_mode false
+
+let test =
+  [
+    ("Create and destroy tracer providers", `Quick, test_create_and_destroy)
+  ; ("Set tracer provider", `Quick, test_set_tracer_provider)
+  ]
+
+let () = Alcotest.run "Tracing library" [("trace providers", test)]