feat(bridge): export basic usage info for telemetry

apps/emqx_bridge/src/emqx_bridge.erl

@@ -60,6 +60,9 @@
 -export([ config_key_path/0
         ]).
 
+%% exported for `emqx_telemetry'
+-export([get_basic_usage_info/0]).
+
 load_hook() ->
     Bridges = emqx:get_config([bridges], #{}),
     load_hook(Bridges).
@@ -244,7 +247,7 @@ update(Type, Name, {OldConf, Conf}) ->
     %% the `method` or `headers` of a HTTP bridge is changed, then the bridge can be updated
     %% without restarting the bridge.
     %%
-    case if_only_to_toggole_enable(OldConf, Conf) of
+    case if_only_to_toggle_enable(OldConf, Conf) of
         false ->
             ?SLOG(info, #{msg => "update bridge", type => Type, name => Name,
                 config => Conf}),
@@ -396,7 +399,7 @@ maybe_disable_bridge(Type, Name, Conf) ->
         true -> ok
     end.
 
-if_only_to_toggole_enable(OldConf, Conf) ->
+if_only_to_toggle_enable(OldConf, Conf) ->
     #{added := Added, removed := Removed, changed := Updated} =
         emqx_map_lib:diff_maps(OldConf, Conf),
     case {Added, Removed, Updated} of
@@ -407,6 +410,31 @@ if_only_to_toggole_enable(OldConf, Conf) ->
         {_, _, _} -> false
     end.
 
+-spec get_basic_usage_info() ->
+          #{ num_bridges => non_neg_integer()
+           , count_by_type =>
+                 #{ BridgeType => non_neg_integer()
+                  }
+           } when BridgeType :: atom().
+get_basic_usage_info() ->
+    lists:foldl(
+      fun(#{resource_data := #{config := #{enable := false}}}, Acc) ->
+              Acc;
+         (#{type := BridgeType}, Acc) ->
+              NumBridges = maps:get(num_bridges, Acc),
+              CountByType0 = maps:get(count_by_type, Acc),
+              CountByType = maps:update_with(
+                              binary_to_atom(BridgeType, utf8),
+                              fun(X) -> X + 1 end,
+                              1,
+                              CountByType0),
+              Acc#{ num_bridges => NumBridges + 1
+                  , count_by_type => CountByType
+                  }
+      end,
+      #{num_bridges => 0, count_by_type => #{}},
+      list()).
+
 bin(Bin) when is_binary(Bin) -> Bin;
 bin(Str) when is_list(Str) -> list_to_binary(Str);
 bin(Atom) when is_atom(Atom) -> atom_to_binary(Atom, utf8).

apps/emqx_bridge/src/emqx_bridge_monitor.erl

@@ -19,6 +19,8 @@
 
 -behaviour(gen_server).
 
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
+
 %% API functions
 -export([ start_link/0
         , ensure_all_started/1
@@ -67,6 +69,11 @@ code_change(_OldVsn, State, _Extra) ->
 load_bridges(Configs) ->
     lists:foreach(fun({Type, NamedConf}) ->
             lists:foreach(fun({Name, Conf}) ->
-                    emqx_bridge:create(Type, Name, Conf)
+                    _Res = emqx_bridge:create(Type, Name, Conf),
+                    ?tp(emqx_bridge_monitor_loaded_bridge,
+                        #{ type => Type
+                         , name => Name
+                         , res  => _Res
+                         })
                 end, maps:to_list(NamedConf))
         end, maps:to_list(Configs)).

apps/emqx_bridge/test/emqx_bridge_SUITE.erl

@@ -0,0 +1,112 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2022 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_bridge_SUITE).
+
+-compile(nowarn_export_all).
+-compile(export_all).
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("common_test/include/ct.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
+
+all() ->
+     emqx_common_test_helpers:all(?MODULE).
+
+init_per_suite(Config) ->
+    %% to avoid inter-suite dependencies
+    application:stop(emqx_connector),
+    ok = emqx_common_test_helpers:start_apps([emqx, emqx_bridge]),
+    Config.
+
+end_per_suite(_Config) ->
+    emqx_common_test_helpers:stop_apps([emqx, emqx_bridge]).
+
+init_per_testcase(t_get_basic_usage_info_1, Config) ->
+    setup_fake_telemetry_data(),
+    Config;
+init_per_testcase(_TestCase, Config) ->
+    Config.
+
+end_per_testcase(t_get_basic_usage_info_1, _Config) ->
+    ok = emqx_bridge:remove(<<"http:basic_usage_info_http">>),
+    ok = emqx_bridge:remove(<<"http:basic_usage_info_http_disabled">>),
+    ok = emqx_bridge:remove(<<"mqtt:basic_usage_info_mqtt">>),
+    emqx_config:delete_override_conf_files(),
+    ok;
+end_per_testcase(_TestCase, _Config) ->
+    ok.
+
+t_get_basic_usage_info_0(_Config) ->
+    ?assertEqual(
+       #{ num_bridges => 0
+        , count_by_type => #{}
+        },
+       emqx_bridge:get_basic_usage_info()).
+
+t_get_basic_usage_info_1(_Config) ->
+    BasicUsageInfo = emqx_bridge:get_basic_usage_info(),
+    ?assertEqual(
+       #{ num_bridges => 2
+        , count_by_type => #{ http => 1
+                            , mqtt => 1
+                            }
+        },
+       BasicUsageInfo).
+
+setup_fake_telemetry_data() ->
+    ConnectorConf =
+        #{<<"connectors">> =>
+              #{<<"mqtt">> => #{<<"my_mqtt_connector">> => #{}}}},
+    MQTTConfig = #{ connector => <<"mqtt:my_mqtt_connector">>
+                  , enable => true
+                  , direction => ingress
+                  , remote_topic => <<"aws/#">>
+                  , remote_qos => 1
+                  },
+    HTTPConfig = #{ url => <<"http://localhost:9901/messages/${topic}">>
+                  , enable => true
+                  , direction => egress
+                  , local_topic => "emqx_http/#"
+                  , method => post
+                  , body => <<"${payload}">>
+                  , headers => #{}
+                  , request_timeout => "15s"
+                  },
+    Conf =
+        #{ <<"bridges">> =>
+               #{ <<"http">> =>
+                      #{ <<"basic_usage_info_http">> => HTTPConfig
+                       , <<"basic_usage_info_http_disabled">> =>
+                             HTTPConfig#{enable => false}
+                       }
+                , <<"mqtt">> =>
+                      #{ <<"basic_usage_info_mqtt">> => MQTTConfig
+                       }
+                }
+         },
+    ok = emqx_common_test_helpers:load_config(emqx_connector_schema, ConnectorConf),
+    ok = emqx_common_test_helpers:load_config(emqx_bridge_schema, Conf),
+
+    ok = snabbkaffe:start_trace(),
+    Predicate = fun(#{?snk_kind := K}) -> K =:= emqx_bridge_monitor_loaded_bridge end,
+    NEvents = 3,
+    BackInTime = 0,
+    Timeout = 1_000,
+    {ok, Sub} = snabbkaffe_collector:subscribe(Predicate, NEvents, Timeout, BackInTime),
+    ok = emqx_bridge:load(),
+    {ok, _} = snabbkaffe_collector:receive_events(Sub),
+    ok = snabbkaffe:stop(),
+    ok.