Ensure probe metrics are gauge type

esl · Nov 4, 2024 · ccc6eb9 · ccc6eb9
1 parent af53925
commit ccc6eb9
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Showing 2 changed files with 47 additions and 3 deletions.
diff --git a/src/instrument/mongoose_instrument.erl b/src/instrument/mongoose_instrument.erl
@@ -46,6 +46,7 @@
 -type handler_key() :: atom(). % key in the `instrumentation' section of the config file
 -type handler_fun() :: fun((event_name(), labels(), config(), measurements()) -> any()).
 -type handlers() :: {[handler_fun()], config()}.
+-type handler_map() :: #{labels() => handlers()}.
 -type execution_time() :: integer().
 -type measure_fun(Result) :: fun((execution_time(), Result) -> measurements()).
 -type handler_module_opts() :: #{atom() => any()}.
@@ -274,16 +275,45 @@ set_up_and_register_event(EventName, Labels, Config, Events) ->
             {ExistingLabels, _, _} = maps:next(maps:iterator(HandlerMap)),
             case label_keys(ExistingLabels) of
                 LabelKeys ->
-                    Handlers = do_set_up(EventName, Labels, Config),
-                    Events#{EventName := HandlerMap#{Labels => Handlers}};
+                    handle_metrics_config(EventName, Labels, Config, HandlerMap, Events);
                 ExistingKeys ->
                     {error, #{what => inconsistent_labels,
                               event_name => EventName, labels => Labels,
                               existing_label_keys => ExistingKeys}}
             end;
         #{} ->
+            handle_metrics_config(EventName, Labels, Config, new, Events)
+    end.
+
+-spec handle_metrics_config(event_name(), labels(), config(), handler_map() | new, event_map()) ->
+          event_map() | {error, map()}.
+handle_metrics_config(EventName, Labels, Config, HandlerMap, Events) ->
+    case filter_improper_probe_metrics(Config) of
+        {ok, _} ->
             Handlers = do_set_up(EventName, Labels, Config),
-            Events#{EventName => #{Labels => Handlers}}
+            case HandlerMap of
+                new ->
+                    Events#{EventName => #{Labels => Handlers}};
+                _ ->
+                    Events#{EventName := HandlerMap#{Labels => Handlers}}
+            end;
+        {error, FilteredMetrics} ->
+            {error, #{what => non_gauge_metrics_in_probe,
+                      event_name => EventName, labels => Labels,
+                      improper_metrics => FilteredMetrics}}
+    end.
+
+-spec filter_improper_probe_metrics(config()) -> {ok, #{}} | {error, metrics()}.
+filter_improper_probe_metrics(Config) ->
+    case Config of
+        #{probe := _, metrics := Metrics} ->
+            FilteredMetrics = maps:filter(fun(_, V) -> V =/= gauge end, Metrics),
+            case map_size(FilteredMetrics) of
+                0 -> {ok, FilteredMetrics};
+                _ -> {error, FilteredMetrics}
+            end;
+        _ ->
+          {ok, #{}}
     end.
 
 -spec do_set_up(event_name(), labels(), config()) -> handlers().

diff --git a/test/mongoose_instrument_SUITE.erl b/test/mongoose_instrument_SUITE.erl
@@ -37,6 +37,7 @@ api_test_cases() ->
      set_up_and_span_with_error,
      span_fails_when_not_set_up,
      set_up_probe,
+     set_up_probe_with_incorrect_metric_type,
      set_up_failing_probe,
      set_up_and_tear_down_probe,
      unexpected_events,
@@ -224,6 +225,19 @@ set_up_probe(Config) ->
                                              fun(L) -> length(L) > 1 end),
     ?assertEqual([ExpectedEvent, ExpectedEvent], History2).
 
+set_up_probe_with_incorrect_metric_type(Config) ->
+    Event = ?config(event, Config),
+    Cfg = #{metrics => #{test_metric => gauge},
+            probe => #{module => ?MODULE, interval => 1}},
+    Cfg1 = #{metrics => ImproperMetrics = #{test_metric => spiral},
+             probe => #{module => ?MODULE, interval => 1}},
+    Specs = [{Event, #{key => value1}, Cfg},
+             {Event, #{key => value2}, Cfg1}],
+    ?assertError(#{what := non_gauge_metrics_in_probe, improper_metrics := ImproperMetrics},
+                 mongoose_instrument:set_up(Event, ?LABELS, Cfg1)),
+    ?assertError(#{what := non_gauge_metrics_in_probe, improper_metrics := ImproperMetrics},
+                 mongoose_instrument:set_up(Specs)).
+
 set_up_failing_probe(Config) ->
     Event = ?config(event, Config),
     Labels = ?LABELS,