From 3db0159573742b1196f6799a1b5e54df2b09272a Mon Sep 17 00:00:00 2001
From: anlicheng <244108715@qq.com>
Date: Mon, 18 Aug 2025 17:06:33 +0800
Subject: [PATCH] add kafka support

---
 apps/iot/src/endpoint/endpoint_kafka.erl | 176 +++++++++++++++++++++++
 apps/iot/src/endpoint/endpoint_mqtt.erl  |   4 +-
 2 files changed, 178 insertions(+), 2 deletions(-)
 create mode 100644 apps/iot/src/endpoint/endpoint_kafka.erl

diff --git a/apps/iot/src/endpoint/endpoint_kafka.erl b/apps/iot/src/endpoint/endpoint_kafka.erl
new file mode 100644
index 0000000..c3badcd
--- /dev/null
+++ b/apps/iot/src/endpoint/endpoint_kafka.erl
@@ -0,0 +1,176 @@
+
+%%%-------------------------------------------------------------------
+%%% @author aresei
+%%% @copyright (C) 2023, <COMPANY>
+%%% @doc
+%%%
+%%% @end
+%%% Created : 06. 7月 2023 12:02
+%%%-------------------------------------------------------------------
+-module(endpoint_kafka).
+
+-include("endpoint.hrl").
+-behaviour(gen_server).
+
+%% API
+-export([start_link/3]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+
+%% 消息重发间隔
+-define(RETRY_INTERVAL, 5000).
+
+-define(DISCONNECTED, disconnected).
+-define(CONNECTED, connected).
+
+-record(state, {
+    endpoint :: #endpoint{},
+    buffer :: endpoint_buffer:buffer(),
+    client_id :: atom(),
+    client_pid :: undefined | pid(),
+    status = ?DISCONNECTED
+}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+%% @doc Creates a gen_statem process which calls Module:init/1 to
+%% initialize. To ensure a synchronized start-up procedure, this
+%% function does not return until Module:init/1 has returned.
+start_link(LocalName, AliasName, Endpoint = #endpoint{}) when is_atom(LocalName), is_atom(AliasName) ->
+    gen_server:start_link({local, LocalName}, ?MODULE, [AliasName, Endpoint], []).
+
+%%%===================================================================
+%%% gen_statem callbacks
+%%%===================================================================
+
+%% @private
+%% @doc Whenever a gen_statem is started using gen_statem:start/[3,4] or
+%% gen_statem:start_link/[3,4], this function is called by the new
+%% process to initialize.
+init([AliasName, Endpoint = #endpoint{id = Id}]) ->
+    iot_name_server:register(AliasName, self()),
+    erlang:process_flag(trap_exit, true),
+    %% 创建转发器, 避免阻塞当前进程的创建，因此采用了延时初始化的机制
+    erlang:start_timer(0, self(), connect),
+    %% 初始化存储
+    Buffer = endpoint_buffer:new(Endpoint, 10),
+    ClientId = list_to_atom("brod_client:" ++ integer_to_list(Id)),
+
+    {ok, #state{endpoint = Endpoint, buffer = Buffer, status = ?DISCONNECTED, client_id = ClientId}}.
+
+%% @private
+%% @doc Handling call messages
+-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
+    State :: #state{}) ->
+    {reply, Reply :: term(), NewState :: #state{}} |
+    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_call(get_stat, _From, State = #state{buffer = Buffer}) ->
+    Stat = endpoint_buffer:stat(Buffer),
+    {reply, {ok, Stat}, State}.
+
+%% @private
+%% @doc Handling cast messages
+-spec(handle_cast(Request :: term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_cast({forward, ServiceId, Metric}, State = #state{buffer = Buffer}) ->
+    NBuffer = endpoint_buffer:append({ServiceId, Metric}, Buffer),
+    {noreply, State#state{buffer = NBuffer}}.
+
+%% @private
+%% @doc Handling all non call/cast messages
+-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_info({timeout, _, connect}, State = #state{buffer = Buffer, status = ?DISCONNECTED, client_id = ClientId,
+    endpoint = #endpoint{title = Title, config = #kafka_endpoint{username = Username, password = Password, bootstrap_servers = BootstrapServers0, topic = Topic}}}) ->
+    lager:debug("[iot_endpoint] endpoint: ~p, create postman", [Title]),
+
+    BootstrapServers = lists:flatmap(fun(S) ->
+        case binary:split(S, <<":">>) of
+            [Host0, Port] ->
+                [{binary_to_list(Host0), binary_to_integer(Port)}];
+            _ ->
+                []
+        end
+                                     end, BootstrapServers0),
+    ClientConfig = [
+        {reconnect_cool_down_seconds, 5},
+        {socket_options, [{keepalive, true}]}
+    ],
+    case brod:start_link_client(BootstrapServers, ClientId, ClientConfig) of
+        {ok, ClientPid} ->
+            ok = brod:start_producer(ClientId, Topic, _ProducerConfig = []),
+            NBuffer = endpoint_buffer:trigger_next(Buffer),
+            {noreply, State#state{buffer = NBuffer, client_pid = ClientPid, status = ?CONNECTED}};
+        {error, Reason} ->
+            lager:debug("[endpoint_kafka] start_client: ~p, get error: ~p", [ClientId, Reason]),
+            retry_connect(),
+            {noreply, State#state{status = ?DISCONNECTED, client_pid = undefined}}
+    end;
+
+%% 离线时，忽略数据发送逻辑
+handle_info({next_data, _Id, _Tuple}, State = #state{status = ?DISCONNECTED}) ->
+    {keep_state, State};
+%% 发送数据到mqtt服务器
+handle_info({next_data, Id, {_ServiceId, Metric}}, State = #state{status = ?CONNECTED, client_pid = ClientPid,
+    endpoint = #endpoint{config = #kafka_endpoint{topic = Topic}}}) ->
+
+    ReceiverPid = self(),
+    AckCb = fun(Partition, BaseOffset) ->
+        lager:debug("[endpoint_kafka] ack partion: ~p, offset: ~p", [Partition, BaseOffset]),
+        ReceiverPid ! {ack, Id}
+            end,
+    ok = brod:produce_cb(ClientPid, Topic, random, <<>>, Metric, AckCb),
+
+    {noreply, State};
+
+handle_info({ack, Id}, State = #state{buffer = Buffer}) ->
+    NBuffer = endpoint_buffer:ack(Id, Buffer),
+    {noreply, State#state{buffer = NBuffer}};
+
+%% postman进程挂掉时，重新建立新的
+handle_info({'EXIT', ClientPid, Reason}, State = #state{client_pid = ClientPid, endpoint = #endpoint{title = Title}}) ->
+    lager:warning("[endpoint_kafka] endpoint: ~p, conn pid exit with reason: ~p", [Title, Reason]),
+    retry_connect(),
+    {noreply, State#state{client_pid = undefined, status = ?DISCONNECTED}};
+
+handle_info(Info, State = #state{status = Status}) ->
+    lager:warning("[endpoint_kafka] unknown message: ~p, status: ~p", [Info, Status]),
+    {noreply, State}.
+
+%% @private
+%% @doc This function is called by a gen_server when it is about to
+%% terminate. It should be the opposite of Module:init/1 and do any
+%% necessary cleaning up. When it returns, the gen_server terminates
+%% with Reason. The return value is ignored.
+-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
+    State :: #state{}) -> term()).
+terminate(Reason, #state{endpoint = #endpoint{title = Title}, buffer = Buffer}) ->
+    lager:debug("[endpoint_kafka] endpoint: ~p, terminate with reason: ~p", [Title, Reason]),
+    endpoint_buffer:cleanup(Buffer),
+    ok.
+
+%% @private
+%% @doc Convert process state when code is changed
+-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
+    Extra :: term()) ->
+    {ok, NewState :: #state{}} | {error, Reason :: term()}).
+code_change(_OldVsn, State = #state{}, _Extra) ->
+    {ok, State}.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+
+retry_connect() ->
+    erlang:start_timer(?RETRY_INTERVAL, self(), connect).
\ No newline at end of file
diff --git a/apps/iot/src/endpoint/endpoint_mqtt.erl b/apps/iot/src/endpoint/endpoint_mqtt.erl
index d501921..2f13a01 100644
--- a/apps/iot/src/endpoint/endpoint_mqtt.erl
+++ b/apps/iot/src/endpoint/endpoint_mqtt.erl
@@ -82,8 +82,8 @@ handle_call(get_stat, _From, State = #state{buffer = Buffer}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({forward, ServiceId, Format, Metric}, State = #state{buffer = Buffer}) ->
-    NBuffer = endpoint_buffer:append({ServiceId, Format, Metric}, Buffer),
+handle_cast({forward, ServiceId, Metric}, State = #state{buffer = Buffer}) ->
+    NBuffer = endpoint_buffer:append({ServiceId, Metric}, Buffer),
     {noreply, State#state{buffer = NBuffer}}.
 
 %% @private