feat: begin to impl connector

apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb.app.src

@@ -1,9 +1,9 @@
-{application, emqx_bridge_greptimedb,
+{application, emqx_bridge_greptimedb, [
- [{description, "An OTP library"},
+    {description, "An OTP library"},
     {vsn, "0.1.0"},
     {registered, []},
-  {applications,
+    {applications, [
-   [kernel,
+        kernel,
         stdlib
     ]},
     {env, []},

apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb_connector.erl

@@ -1 +1,114 @@
 -module(emqx_bridge_greptimedb_connector).
+-include_lib("emqx/include/logger.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
+
+%% `emqx_resource' API
+-export([
+    callback_mode/0,
+    on_start/2,
+    on_stop/2,
+    on_get_status/2,
+    on_query/3,
+    on_query_async/4,
+    on_batch_query/3,
+    on_batch_query_async/4
+]).
+
+-define(GREPTIMEDB_DEFAULT_PORT, 4001).
+
+-define(GREPTIMEDB_HOST_OPTIONS, #{
+    default_port => ?GREPTIMEDB_DEFAULT_PORT
+}).
+
+%%-------------------------------------------------------------------------------------
+%% `emqx_resource' API
+%%-------------------------------------------------------------------------------------
+callback_mode() -> async_if_possible.
+
+on_start(InstId, Config) ->
+    start_client(InstId, Config).
+
+on_stop(_InstId, #{client := Client}) ->
+    greptimedb:stop_client(Client).
+
+on_get_status(_InstId, _State) ->
+    %% FIXME
+    connected.
+
+on_query(_InstanceId, {send_message, _Message}, _State) ->
+    todo.
+
+on_query_async(_InstanceId, {send_message, _Message}, _ReplyFunAndArgs0, _State) ->
+    todo.
+
+on_batch_query(
+    _ResourceID,
+    _BatchReq,
+    _State
+) ->
+    todo.
+
+on_batch_query_async(
+    _InstId,
+    _BatchData,
+    {_ReplyFun, _Args},
+    _State
+) ->
+    todo.
+
+%% internal functions
+
+start_client(InstId, Config) ->
+    ClientConfig = client_config(InstId, Config),
+    ?SLOG(info, #{
+        msg => "starting GreptimeDB connector",
+        connector => InstId,
+        config => emqx_utils:redact(Config),
+        client_config => emqx_utils:redact(ClientConfig)
+    }),
+    try
+        case greptimedb:start_client(ClientConfig) of
+            {ok, Client} ->
+                {ok, #{client => Client}};
+            {error, Reason} ->
+                ?tp(greptimedb_connector_start_failed, #{error => Reason}),
+                ?SLOG(warning, #{
+                    msg => "failed_to_start_greptimedb_connector",
+                    connector => InstId,
+                    reason => Reason
+                }),
+                {error, Reason}
+        end
+    catch
+        E:R:S ->
+            ?tp(greptimedb_connector_start_exception, #{error => {E, R}}),
+            ?SLOG(warning, #{
+                msg => "start greptimedb connector error",
+                connector => InstId,
+                error => E,
+                reason => R,
+                stack => S
+            }),
+            {error, R}
+    end.
+
+client_config(
+    InstId,
+    _Config = #{
+        server := Server
+    }
+) ->
+    #{hostname := Host, port := Port} = emqx_schema:parse_server(Server, ?GREPTIMEDB_HOST_OPTIONS),
+    [
+        {endpoints, [{http, str(Host), Port}]},
+        {pool_size, erlang:system_info(schedulers)},
+        {pool, InstId},
+        {pool_type, random}
+    ].
+
+str(A) when is_atom(A) ->
+    atom_to_list(A);
+str(B) when is_binary(B) ->
+    binary_to_list(B);
+str(S) when is_list(S) ->
+    S.