Merge branch 'dev' of github.com:emqtt/emqtt into dev

src/emqttd_plugin_mgr.erl

@@ -0,0 +1,210 @@
+%%%-----------------------------------------------------------------------------
+%%% Copyright (c) 2012-2015 eMQTT.IO, All Rights Reserved.
+%%%
+%%% Permission is hereby granted, free of charge, to any person obtaining a copy
+%%% of this software and associated documentation files (the "Software"), to deal
+%%% in the Software without restriction, including without limitation the rights
+%%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+%%% copies of the Software, and to permit persons to whom the Software is
+%%% furnished to do so, subject to the following conditions:
+%%%
+%%% The above copyright notice and this permission notice shall be included in all
+%%% copies or substantial portions of the Software.
+%%%
+%%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+%%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+%%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+%%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+%%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+%%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+%%% SOFTWARE.
+%%%-----------------------------------------------------------------------------
+%%% @doc
+%%% emqttd plugin manager.
+%%%
+%%% @end
+%%%-----------------------------------------------------------------------------
+
+-module(emqttd_plugin_mgr).
+
+-author("Feng Lee <feng@emqtt.io>").
+
+-include("emqttd.hrl").
+
+-export([start/0, list/0, load/1, unload/1, stop/0]).
+
+%%------------------------------------------------------------------------------
+%% @doc Load all plugins
+%% @end
+%%------------------------------------------------------------------------------
+-spec start() -> ok | {error, any()}.
+start() ->
+    case read_loaded() of
+        {ok, AppNames} ->
+            NotFound = AppNames -- apps(plugin),
+            case NotFound of
+                [] -> ok;
+                NotFound -> lager:error("Cannot find plugins: ~p", [NotFound])
+            end,
+            {ok, start_apps(AppNames -- NotFound -- apps(started))};
+        {error, Error} ->
+            lager:error("Read loaded_plugins file error: ~p", [Error]),
+            {error, Error}
+    end.
+
+%%------------------------------------------------------------------------------
+%% @doc List all available plugins
+%% @end
+%%------------------------------------------------------------------------------
+list() ->
+    {ok, PluginEnv} = application:get_env(emqttd, plugins),
+    PluginsDir = proplists:get_value(dir, PluginEnv, "./plugins"),
+    AppFiles = filelib:wildcard("*/ebin/*.app", PluginsDir),
+    Plugins = [plugin(filename:join(PluginsDir, AppFile)) || AppFile <- AppFiles],
+    StartedApps = [Name || {Name, _Descr, _Ver} <- application:which_applications()],
+    lists:map(fun(Plugin = #mqtt_plugin{name = Name}) ->
+                      case lists:member(Name, StartedApps) of
+                          true  -> Plugin#mqtt_plugin{active = true};
+                          false -> Plugin
+                      end
+              end, Plugins).
+
+plugin(AppFile) ->
+    {ok, [{application, Name, Attrs}]} = file:consult(AppFile),
+    Ver = proplists:get_value(vsn, Attrs, "0"),
+    Descr = proplists:get_value(description, Attrs, ""),
+    #mqtt_plugin{name = Name, version = Ver, descr = Descr}.
+
+%%------------------------------------------------------------------------------
+%% @doc Load Plugin
+%% @end
+%%------------------------------------------------------------------------------
+-spec load(atom()) -> ok | {error, any()}.
+load(PluginName) when is_atom(PluginName) ->
+    case lists:member(PluginName, apps(started)) of
+        true ->
+            lager:info("plugin ~p is started", [PluginName]),
+            {error, already_started};
+        false ->
+            case lists:member(PluginName, apps(plugin)) of
+                true ->
+                    load_plugin(PluginName);
+                false ->
+                    lager:info("plugin ~p is not found", [PluginName]),
+                    {error, not_foun}
+            end
+    end.
+    
+-spec load_plugin(App :: atom()) -> {ok, list()} | {error, any()}.
+load_plugin(PluginName) ->
+    case start_app(PluginName) of
+        {ok, Started} ->
+            plugin_loaded(PluginName),
+            {ok, Started};
+        {error, Error} ->
+            {error, Error}
+    end.
+
+start_app(App) ->
+    case application:ensure_all_started(App) of
+        {ok, Started} ->
+            lager:info("started apps: ~p, load plugin ~p successfully", [Started, App]),
+            {ok, Started};
+        {error, {ErrApp, Reason}} ->
+            lager:error("load plugin ~p error, cannot start app ~s for ~p", [App, ErrApp, Reason]),
+            {error, {ErrApp, Reason}}
+    end.
+
+%%------------------------------------------------------------------------------
+%% @doc UnLoad Plugin
+%% @end
+%%------------------------------------------------------------------------------
+-spec unload(atom()) -> ok | {error, any()}.
+unload(PluginName) when is_atom(PluginName) ->
+    %% stop plugin
+    %% write file if plugin is loaded
+    ok.
+
+-spec unload_plugin(App :: atom()) -> ok | {error, any()}.
+unload_plugin(App) ->
+    case stop_app(App) of
+        ok ->
+            unload_app(App);
+        {error, Reason} ->
+            {error, Reason}
+    end.
+    
+stop_app(App) ->
+    case application:stop(App) of
+        ok ->
+            lager:info("stop plugin ~p successfully~n", [App]), ok;
+        {error, {not_started, App}} ->
+            lager:error("plugin ~p is not started~n", [App]), ok;
+        {error, Reason} ->
+            lager:error("stop plugin ~p error: ~p", [App]), {error, Reason}
+    end.
+
+unload_app(App) ->
+    case application:unload(App) of
+        ok ->
+            lager:info("unload plugin ~p successfully~n", [App]), ok;
+        {error, {not_loaded, App}} ->
+            lager:info("load plugin ~p is not loaded~n", [App]), ok;
+        {error, Reason} ->
+            lager:error("unload plugin ~p error: ~p", [App, Reason]), {error, Reason}
+    end.
+
+stop() ->
+    %% stop all plugins
+    PluginApps = application:get_env(emqttd, plugins, []),
+    %%[{App, unload_plugin(App)} || App <- PluginApps].
+    ok.
+
+%%%=============================================================================
+%%% Internal functions
+%%%=============================================================================
+
+start_apps(Apps) ->
+    [start_app(App) || App <- Apps].
+
+stop_apps(Apps) ->
+    [stop_app(App) || App <- Apps].
+
+apps(plugin) ->
+    [Name || #mqtt_plugin{name = Name} <- list()];
+
+apps(started) ->
+    [Name || {Name, _Descr, _Ver} <- application:which_applications()].
+
+plugin_loaded(Name) ->
+    case read_loaded() of
+        {ok, Names} ->
+            case lists:member(Name, Names) of
+                true ->
+                    ok;
+                false ->
+                    %% write file if plugin is loaded
+                    write_loaded(lists:append(Names, Name))
+            end;
+        {error, Error} ->
+            lager:error("Cannot read loaded plugins: ~p", [Error])
+    end.
+
+
+
+read_loaded() ->
+    {ok, PluginEnv} = application:get_env(emqttd, plugins),
+    LoadedFile = proplists:get_value(loaded_file, PluginEnv, "./data/loaded_plugins"),
+    file:consult(LoadedFile).
+
+write_loaded(AppNames) ->
+    {ok, PluginEnv} = application:get_env(emqttd, plugins),
+    LoadedFile = proplists:get_value(loaded_file, PluginEnv, "./data/loaded_plugins"),
+    case file:open(LoadedFile, [binary, write]) of
+        {ok, Fd} ->
+            Line = list_to_binary(io_lib:format("~w.~n", [AppNames])),
+            file:write(Fd, Line);
+        {error, Error} ->
+            {error, Error}
+    end.
+