fix micro service

apps/efka/src/efka_micro_service.erl

@@ -13,6 +13,10 @@
 
 -behaviour(gen_server).
 
+%% 当前微服务的状态
+-define(STATUS_STOPPED, stopped).
+-define(STATUS_RUNNING, running).
+
 %% API
 -export([start_link/2]).
 -export([get_name/1, get_pid/1, start_service/1, stop_service/1, attach_channel/2]).
@@ -25,7 +29,9 @@
     %% 通道id信息
     channel_pid :: pid() | undefined,
     %% 当前进程的port信息, OSPid = erlang:port_info(Port, os_pid)
-    port :: undefined | port()
+    port :: undefined | port(),
+    %% 当前服务的运行状态
+    running_status = ?STATUS_STOPPED
 }).
 
 %%%===================================================================
@@ -44,9 +50,11 @@ get_pid(ServiceId) when is_binary(ServiceId) ->
 attach_channel(Pid, ChannelPid) when is_pid(Pid), is_pid(ChannelPid) ->
     gen_server:call(Pid, {attach_channel, ChannelPid}).
 
+-spec start_service(Pid :: pid()) -> ok | {error, Reason :: binary()}.
 start_service(Pid) when is_pid(Pid) ->
     gen_server:call(Pid, start_service).
 
+-spec stop_service(Pid :: pid()) -> ok | {error, Reason :: binary()}.
 stop_service(Pid) when is_pid(Pid) ->
     gen_server:call(Pid, stop_service).
 
@@ -65,9 +73,11 @@ start_link(Name, Service = #micro_service{}) when is_atom(Name) ->
 -spec(init(Args :: term()) ->
     {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term()} | ignore).
-init([Service]) ->
-    erlang:start_timer(0, self(), boot_service),
-    {ok, #state{service = Service}}.
+init([Service = #micro_service{status = Status}]) ->
+    %% 数据的状态和运行状态是2回事
+    Status == 1 andalso erlang:start_timer(0, self(), boot_service),
+
+    {ok, #state{service = Service, running_status = ?STATUS_STOPPED}}.
 
 %% @private
 %% @doc Handling call messages
@@ -91,19 +101,32 @@ handle_call({attach_channel, ChannelPid}, _From, State = #state{channel_pid = Ol
             {reply, {error, <<"serivce stopped">>}, State}
     end;
 
-%% 启动服务
-handle_call(start_service, _From, State = #state{service = Service = #micro_service{service_id = ServiceId}}) ->
+%% 启动服务: 当前服务如果正常运行，则重启
+handle_call(start_service, _From, State = #state{running_status = RunningStatus, port = Port, service = Service = #micro_service{service_id = ServiceId}}) ->
+    %% 运行中的服务，先停止
+    RunningStatus == ?STATUS_RUNNING andalso stop_port(Port),
+
     %% 更新数据库状态
     ok = micro_service_model:start_service(ServiceId),
     %% 异步启动服务
-    erlang:start_timer(0, self(), boot_service),
-    {reply, ok, State#state{service = Service#micro_service{status = 1}}};
+    case boot_service(Service) of
+        {ok, Port} ->
+            {reply, ok, State#state{running_status = ?STATUS_RUNNING, port = Port, service = Service#micro_service{status = 1}}};
+        {error, Reason} ->
+            %% 启动失败不能更新数据库里面的状态
+            {reply, {error, Reason}, State#state{running_status = ?STATUS_STOPPED}}
+    end;
 
 %% 停止服务
-handle_call(stop_service, _From, State = #state{port = Port, service = Service = #micro_service{service_id = ServiceId}}) ->
-    ok = micro_service_model:stop_service(ServiceId),
-    stop_port(Port),
-    {reply, ok, State#state{port = undefined, service = Service#micro_service{status = 0}}};
+handle_call(stop_service, _From, State = #state{running_status = RunningStatus, port = Port, service = Service = #micro_service{service_id = ServiceId}}) ->
+    case RunningStatus of
+        ?STATUS_STOPPED ->
+            {reply, {error, <<"service not running">>}, State};
+        ?STATUS_RUNNING ->
+            ok = micro_service_model:stop_service(ServiceId),
+            stop_port(Port),
+            {reply, ok, State#state{port = undefined, service = Service#micro_service{status = 0}}}
+    end;
 
 handle_call(_Request, _From, State = #state{}) ->
     {reply, ok, State}.
@@ -129,20 +152,25 @@ handle_info({timeout, _, boot_service}, State = #state{service = #micro_service{
 handle_info({timeout, _, boot_service}, State = #state{service = Service = #micro_service{service_id = ServiceId, status = 1}}) ->
     case boot_service(Service) of
         {ok, Port} ->
-            {noreply, State#state{port = Port}};
+            {noreply, State#state{running_status = ?STATUS_RUNNING, port = Port}};
         {error, Reason} ->
             lager:debug("[efka_micro_service] service: ~p, boot_service get error: ~p", [ServiceId, Reason]),
-            {noreply, State}
+            {noreply, State#state{running_status = ?STATUS_STOPPED}}
     end;
 
 handle_info({Port, {data, Data}}, State = #state{port = Port, service = Service}) ->
     lager:debug("[efka_micro_service] service_id: ~p, port data: ~p", [Service#micro_service.service_id, Data]),
     {noreply, State};
-%% 处理port的消息
+%% 处理port的消息, Port的被动关闭会触发；因此这个时候的Port和State.port的值是相等的
 handle_info({Port, {exit_status, Code}}, State = #state{port = Port, service = Service}) ->
     lager:debug("[efka_micro_service] service_id: ~p, port exit with code: ~p", [Service#micro_service.service_id, Code]),
     erlang:start_timer(5000, self(), boot_service),
 
+    {noreply, State#state{port = undefined}};
+
+%% 主动关闭的port，不能启动重启的逻辑
+handle_info({Port, {exit_status, Code}}, State = #state{service = Service}) when is_port(Port) ->
+    lager:debug("[efka_micro_service] service_id: ~p, port close with code: ~p", [Service#micro_service.service_id, Code]),
     {noreply, State#state{port = undefined}}.
 
 %% @private