feat(rocketmq): add support for namespace and key dispatch strategy

apps/emqx_bridge_rocketmq/src/emqx_bridge_rocketmq.erl

@@ -163,10 +163,12 @@ fields(action_parameters) ->
             {template,
                 mk(
                     emqx_schema:template(),
-                    #{
-                        desc => ?DESC("template"),
-                        default => ?DEFAULT_TEMPLATE
-                    }
+                    #{desc => ?DESC("template"), default => ?DEFAULT_TEMPLATE}
+                )},
+            {strategy,
+                mk(
+                    hoconsc:union([roundrobin, binary()]),
+                    #{desc => ?DESC("strategy"), default => roundrobin}
                 )}
         ] ++ emqx_bridge_rocketmq_connector:fields(config),
     lists:foldl(
@@ -176,6 +178,7 @@ fields(action_parameters) ->
         Parameters,
         [
             servers,
+            namespace,
             pool_size,
             auto_reconnect,
             access_key,
@@ -215,6 +218,11 @@ fields("config") ->
             mk(
                 binary(),
                 #{desc => ?DESC("local_topic"), required => false}
+            )},
+        {strategy,
+            mk(
+                hoconsc:union([roundrobin, binary()]),
+                #{desc => ?DESC("strategy"), default => roundrobin}
             )}
     ] ++ emqx_resource_schema:fields("resource_opts") ++
         emqx_bridge_rocketmq_connector:fields(config);

apps/emqx_bridge_rocketmq/src/emqx_bridge_rocketmq_connector.erl

@@ -45,6 +45,11 @@ roots() ->
 fields(config) ->
     [
         {servers, servers()},
+        {namespace,
+            mk(
+                binary(),
+                #{required => false, desc => ?DESC(namespace)}
+            )},
         {topic,
             mk(
                 emqx_schema:template(),
@@ -107,7 +112,7 @@ on_start(
     ),
     ClientId = client_id(InstanceId),
     ACLInfo = acl_info(AccessKey, SecretKey, SecurityToken),
-    ClientCfg = #{acl_info => ACLInfo},
+    ClientCfg = namespace(#{acl_info => ACLInfo}, Config),
 
     State = #{
         client_id => ClientId,
@@ -156,10 +161,12 @@ create_channel_state(
     TopicTks = emqx_placeholder:preproc_tmpl(Topic),
     ProducerOpts = make_producer_opts(Conf, ACLInfo),
     Templates = parse_template(Conf),
+    DispatchStrategy = parse_dispatch_strategy(Conf),
     State = #{
         topic => Topic,
         topic_tokens => TopicTks,
         templates => Templates,
+        dispatch_strategy => DispatchStrategy,
         sync_timeout => SyncTimeout,
         acl_info => ACLInfo,
         producers_opts => ProducerOpts
@@ -250,12 +257,13 @@ do_query(
     #{
         topic_tokens := TopicTks,
         templates := Templates,
+        dispatch_strategy := DispatchStrategy,
         sync_timeout := RequestTimeout,
         producers_opts := ProducerOpts
     } = maps:get(ChannelId, Channels),
 
     TopicKey = get_topic_key(Query, TopicTks),
-    Data = apply_template(Query, Templates),
+    Data = apply_template(Query, Templates, DispatchStrategy),
 
     Result = safe_do_produce(
         InstanceId, QueryFunc, ClientId, TopicKey, Data, ProducerOpts, RequestTimeout
@@ -315,24 +323,57 @@ parse_template([{Key, H} | T], Templates) ->
 parse_template([], Templates) ->
     Templates.
 
+%% returns a procedure to generate the produce context
+parse_dispatch_strategy(#{strategy := roundrobin}) ->
+    fun(_) ->
+        #{}
+    end;
+parse_dispatch_strategy(#{strategy := Template}) ->
+    Tokens = emqx_placeholder:preproc_tmpl(Template),
+    fun(Msg) ->
+        #{
+            key =>
+                case emqx_placeholder:proc_tmpl(Tokens, Msg) of
+                    <<"undefined">> ->
+                        %% Since the key may be absent on some kinds of events (ex:
+                        %% `topic' is absent in `client.disconnected'), and this key is
+                        %% used for routing, we generate a random key when it's absent to
+                        %% better distribute the load, effectively making it `random'
+                        %% dispatch if the key is absent and we are using `key_dispatch'.
+                        %% Otherwise, it'll be deterministic.
+                        emqx_guid:gen();
+                    Key ->
+                        Key
+                end
+        }
+    end.
+
 get_topic_key({_, Msg}, TopicTks) ->
     emqx_placeholder:proc_tmpl(TopicTks, Msg);
 get_topic_key([Query | _], TopicTks) ->
     get_topic_key(Query, TopicTks).
 
-apply_template({Key, Msg} = _Req, Templates) ->
+%% return a message data and its context,
+%% {binary(), rocketmq_producers:produce_context()})
+apply_template({Key, Msg} = _Req, Templates, DispatchStrategy) ->
+    {
+        case maps:get(Key, Templates, undefined) of
+            undefined ->
+                emqx_utils_json:encode(Msg);
+            Template ->
+                emqx_placeholder:proc_tmpl(Template, Msg)
+        end,
+        DispatchStrategy(Msg)
+    };
+apply_template([{Key, _} | _] = Reqs, Templates, DispatchStrategy) ->
     case maps:get(Key, Templates, undefined) of
         undefined ->
-            emqx_utils_json:encode(Msg);
+            [{emqx_utils_json:encode(Msg), DispatchStrategy(Msg)} || {_, Msg} <- Reqs];
         Template ->
-            emqx_placeholder:proc_tmpl(Template, Msg)
-    end;
-apply_template([{Key, _} | _] = Reqs, Templates) ->
-    case maps:get(Key, Templates, undefined) of
-        undefined ->
-            [emqx_utils_json:encode(Msg) || {_, Msg} <- Reqs];
-        Template ->
-            [emqx_placeholder:proc_tmpl(Template, Msg) || {_, Msg} <- Reqs]
+            [
+                {emqx_placeholder:proc_tmpl(Template, Msg), DispatchStrategy(Msg)}
+             || {_, Msg} <- Reqs
+            ]
     end.
 
 client_id(ResourceId) ->
@@ -377,6 +418,10 @@ acl_info(AccessKey, SecretKey, SecurityToken) when is_binary(AccessKey) ->
 acl_info(_, _, _) ->
     #{}.
 
+namespace(ClientCfg, Config) ->
+    Namespace = maps:get(namespace, Config, <<>>),
+    ClientCfg#{namespace => Namespace}.
+
 create_producers_map(ClientId) ->
     _ = ets:new(ClientId, [public, named_table, {read_concurrency, true}]),
     ok.

rel/i18n/emqx_bridge_rocketmq.hocon

@@ -59,4 +59,7 @@ config_connector.desc:
 config_connector.label:
 """RocketMQ Client Configuration"""
 
+strategy.desc:
+"""Producer key dispatch strategy, the default is `roundrobin`, also supports placeholders, such as: `clientid`, `messageid`, `username`."""
+
 }

rel/i18n/emqx_bridge_rocketmq_connector.hocon

@@ -50,4 +50,10 @@ topic.desc:
 topic.label:
 """RocketMQ Topic"""
 
+namespace.desc:
+"""The namespace field MUST be set if you are using the RocketMQ service in
+aliyun cloud and also the namespace is enabled,
+or if you have configured a namespace in your RocketMQ server.
+For RocketMQ in aliyun cloud, the namespace is the instance ID."""
+
 }