feat(bridges): add connector for mqtt bridge

apps/emqx_bridge_mqtt/src/emqx_bridge_mqtt.erl

@@ -50,15 +50,11 @@
 
 start(Config) ->
     Parent = self(),
-    Address = maps:get(address, Config),
+    {Host, Port} = maps:get(server, Config),
     Mountpoint = maps:get(receive_mountpoint, Config, undefined),
     Subscriptions = maps:get(subscriptions, Config, []),
     Subscriptions1 = check_subscriptions(Subscriptions),
     Handlers = make_hdlr(Parent, Mountpoint),
-    {Host, Port} = case string:tokens(Address, ":") of
-                       [H] -> {H, 1883};
-                       [H, P] -> {H, list_to_integer(P)}
-                   end,
     Config1 = Config#{
         msg_handler => Handlers,
         host => Host,

apps/emqx_bridge_mqtt/src/emqx_bridge_mqtt_sup.erl

@@ -39,12 +39,10 @@ start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
 init([]) ->
-    BridgesConf = emqx:get_config([?APP, bridges], []),
-    BridgeSpec = lists:map(fun bridge_spec/1, BridgesConf),
     SupFlag = #{strategy => one_for_one,
                 intensity => 100,
                 period => 10},
-    {ok, {SupFlag, BridgeSpec}}.
+    {ok, {SupFlag, []}}.
 
 bridge_spec(Config) ->
     Name = list_to_atom(maps:get(name, Config)),
@@ -57,7 +55,8 @@ bridge_spec(Config) ->
 
 -spec(bridges() -> [{node(), map()}]).
 bridges() ->
-    [{Name, emqx_bridge_worker:status(Name)} || {Name, _Pid, _, _} <- supervisor:which_children(?MODULE)].
+    [{Name, emqx_bridge_worker:status(Name)}
+     || {Name, _Pid, _, _} <- supervisor:which_children(?MODULE)].
 
 create_bridge(Config) ->
     supervisor:start_child(?MODULE, bridge_spec(Config)).

apps/emqx_bridge_mqtt/src/emqx_bridge_worker.erl

@@ -135,12 +135,12 @@
 %% mountpoint: The topic mount point for messages sent to remote node/cluster
 %%      `undefined', `<<>>' or `""' to disable
 %% forwards: Local topics to subscribe.
-%% queue.batch_bytes_limit: Max number of bytes to collect in a batch for each
+%% replayq.batch_bytes_limit: Max number of bytes to collect in a batch for each
 %%      send call towards emqx_bridge_connect
-%% queue.batch_count_limit: Max number of messages to collect in a batch for
+%% replayq.batch_count_limit: Max number of messages to collect in a batch for
 %%      each send call towards emqx_bridge_connect
-%% queue.replayq_dir: Directory where replayq should persist messages
+%% replayq.dir: Directory where replayq should persist messages
-%% queue.replayq_seg_bytes: Size in bytes for each replayq segment file
+%% replayq.seg_bytes: Size in bytes for each replayq segment file
 %%
 %% Find more connection specific configs in the callback modules
 %% of emqx_bridge_connect behaviour.
@@ -208,7 +208,7 @@ init(Opts) ->
     ConnectOpts = maps:get(config, Opts),
     ConnectModule = conn_type(maps:get(conn_type, ConnectOpts)),
     Forwards = maps:get(forwards, Opts, []),
-    Queue = open_replayq(maps:get(queue, Opts, #{})),
+    Queue = open_replayq(maps:get(replayq, Opts, #{})),
     State = init_opts(Opts),
     self() ! idle,
     {ok, idle, State#{connect_module => ConnectModule,
@@ -236,8 +236,8 @@ init_opts(Opts) ->
       name => Name}.
 
 open_replayq(QCfg) ->
-    Dir = maps:get(replayq_dir, QCfg, undefined),
+    Dir = maps:get(dir, QCfg, undefined),
-    SegBytes = maps:get(replayq_seg_bytes, QCfg, ?DEFAULT_SEG_BYTES),
+    SegBytes = maps:get(seg_bytes, QCfg, ?DEFAULT_SEG_BYTES),
     MaxTotalSize = maps:get(max_total_size, QCfg, ?DEFAULT_MAX_TOTAL_SIZE),
     QueueConfig = case Dir =:= undefined orelse Dir =:= "" of
         true -> #{mem_only => true};

apps/emqx_connector/src/emqx_connector_mqtt.erl

@@ -0,0 +1,141 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 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_connector_mqtt).
+
+-include_lib("typerefl/include/types.hrl").
+-include_lib("emqx_resource/include/emqx_resource_behaviour.hrl").
+
+%% callbacks of behaviour emqx_resource
+-export([ on_start/2
+        , on_stop/2
+        , on_query/4
+        , on_health_check/2
+        ]).
+
+-behaviour(hocon_schema).
+
+-export([ roots/0
+        , fields/1]).
+
+%%=====================================================================
+%% Hocon schema
+roots() ->
+    [{config, #{type => hoconsc:ref(?MODULE, "config")}}].
+
+fields("config") ->
+    [ {server, emqx_schema:t(string(), undefined, "127.0.0.1:1883")}
+    , {reconnect_interval, emqx_schema:t(emqx_schema:duration_ms(), undefined, "30s")}
+    , {proto_ver, fun proto_ver/1}
+    , {bridge_mode, emqx_schema:t(boolean(), undefined, true)}
+    , {clientid, emqx_schema:t(string())}
+    , {username, emqx_schema:t(string())}
+    , {password, emqx_schema:t(string())}
+    , {clean_start, emqx_schema:t(boolean(), undefined, true)}
+    , {keepalive, emqx_schema:t(integer(), undefined, 300)}
+    , {retry_interval, emqx_schema:t(emqx_schema:duration_ms(), undefined, "30s")}
+    , {max_inflight, emqx_schema:t(integer(), undefined, 32)}
+    , {replayq, emqx_schema:t(hoconsc:ref(?MODULE, "replayq"))}
+    , {in, hoconsc:array("in")}
+    , {out, hoconsc:array("out")}
+    ] ++ emqx_connector_schema_lib:ssl_fields();
+
+fields("in") ->
+    [ {from_remote_topic, #{type => binary(), nullable => false}}
+    , {to_local_topic, #{type => binary(), nullable => false}}
+    , {qos, emqx_schema:t(integer(), undefined, 1)}
+    , {payload_template, emqx_schema:t(binary(), undefined, <<"${message}">>)}
+    ];
+
+fields("out") ->
+    [ {to_remote_topic, #{type => binary(), nullable => false}}
+    , {from_local_topic, #{type => binary(), nullable => false}}
+    , {payload_template, emqx_schema:t(binary(), undefined, <<"${payload}">>)}
+    ];
+
+fields("replayq") ->
+    [ {dir, hoconsc:union([boolean(), string()])}
+    , {seg_bytes, emqx_schema:t(emqx_schema:bytesize(), undefined, "100MB")}
+    , {offload_mode, emqx_schema:t(boolean(), undefined, false)}
+    , {max_total_bytes, emqx_schema:t(emqx_schema:bytesize(), undefined, "1024MB")}
+    ].
+
+proto_ver(type) -> hoconsc:enum([v3, v4, v5]);
+proto_ver(default) -> v4;
+proto_ver(_) -> undefined.
+
+%% ===================================================================
+on_start(InstId, #{server := Server,
+                   reconnect_interval := ReconnIntv,
+                   proto_ver := ProtoVer,
+                   bridge_mode := BridgeMod,
+                   clientid := ClientID,
+                   username := User,
+                   password := Password,
+                   clean_start := CleanStart,
+                   keepalive := KeepAlive,
+                   retry_interval := RetryIntv,
+                   max_inflight := MaxInflight,
+                   replayq := ReplayQ,
+                   in := In,
+                   out := Out,
+                   ssl := #{enable := EnableSsl} = Ssl} = Conf) ->
+    logger:info("starting mqtt connector: ~p, ~p", [InstId, Conf]),
+    BridgeConf = Conf#{
+        name => InstId,
+        config => #{
+            conn_type => mqtt,
+            subscriptions => In,
+            forwards => Out,
+            replayq => ReplayQ,
+            %% connection opts
+            server => Server,
+            reconnect_interval => ReconnIntv,
+            proto_ver => ProtoVer,
+            bridge_mode => BridgeMod,
+            clientid => ClientID,
+            username => User,
+            password => Password,
+            clean_start => CleanStart,
+            keepalive => KeepAlive,
+            retry_interval => RetryIntv,
+            max_inflight => MaxInflight,
+            ssl => EnableSsl,
+            ssl_opts => maps:to_list(maps:remove(enable, Ssl)),
+            if_record_metrics => true
+        }
+    },
+    case emqx_bridge_mqtt_sup:create_bridge(BridgeConf) of
+        {ok, _Pid} ->
+            {ok, #{}};
+        {error, {already_started, _Pid}} ->
+            {ok, #{}};
+        {error, Reason} ->
+            {error, Reason}
+    end.
+
+on_stop(InstId, #{}) ->
+    logger:info("stopping mqtt connector: ~p", [InstId]),
+    emqx_bridge_mqtt_sup:drop_bridge(InstId).
+
+%% TODO: let the emqx_resource trigger on_query/4 automatically according to the
+%%  `in` and `out` config
+on_query(InstId, {publish_to_local, Msg}, _AfterQuery, _State) ->
+    logger:debug("publish to local node, connector: ~p, msg: ~p", [InstId, Msg]);
+on_query(InstId, {publish_to_remote, Msg}, _AfterQuery, _State) ->
+    logger:debug("publish to remote node, connector: ~p, msg: ~p", [InstId, Msg]).
+
+on_health_check(InstId, #{}) ->
+    emqx_bridge_mqtt_sup:try_ping(InstId).