feat: refactor influxdb connector to to avoid resources leaking

apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb.app.src

@@ -1,6 +1,6 @@
 {application, emqx_bridge_influxdb, [
     {description, "EMQX Enterprise InfluxDB Bridge"},
-    {vsn, "0.1.1"},
+    {vsn, "0.1.2"},
     {registered, []},
     {applications, [kernel, stdlib, influxdb]},
     {env, []},

apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb_connector.erl

@@ -39,6 +39,9 @@
 
 -type ts_precision() :: ns | us | ms | s.
 
+%% Allocatable resources
+-define(influx_client, influx_client).
+
 -define(INFLUXDB_DEFAULT_PORT, 8086).
 
 %% influxdb servers don't need parse
@@ -53,10 +56,20 @@
 callback_mode() -> async_if_possible.
 
 on_start(InstId, Config) ->
+    %% InstID as pool would be handled by influxdb client
+    %% so there is no need to allocate pool_name here
+    %% ehttpc for influxdb-v1/v2,
+    %% ecpool for influxdb-udp
+    %% See: influxdb:start_client/1
     start_client(InstId, Config).
 
-on_stop(_InstId, #{client := Client}) ->
-    influxdb:stop_client(Client).
+on_stop(InstId, _State) ->
+    case emqx_resource:get_allocated_resources(InstId) of
+        #{?influx_client := Client} ->
+            influxdb:stop_client(Client);
+        _ ->
+            ok
+    end.
 
 on_query(InstId, {send_message, Data}, _State = #{write_syntax := SyntaxLines, client := Client}) ->
     case data_to_points(Data, SyntaxLines) of
@@ -220,8 +233,12 @@ start_client(InstId, Config) ->
         config => emqx_utils:redact(Config),
         client_config => emqx_utils:redact(ClientConfig)
     }),
-    try
-        do_start_client(InstId, ClientConfig, Config)
+    try do_start_client(InstId, ClientConfig, Config) of
+        Res = {ok, #{client := Client}} ->
+            ok = emqx_resource:allocate_resource(InstId, ?influx_client, Client),
+            Res;
+        {error, Reason} ->
+            {error, Reason}
     catch
         E:R:S ->
             ?tp(influxdb_connector_start_exception, #{error => {E, R}}),

changes/ee/feat-10924.en.md

@@ -0,0 +1 @@
+Refactored influxdb bridge connector to avoid resource leaks during crashes at creation.