summaryrefslogtreecommitdiff
path: root/src/rabbit_plugin_activator.erl
blob: e22d844fdf38d89e1b1c02a1baee21615a79d1dd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
%%   The contents of this file are subject to the Mozilla Public License
%%   Version 1.1 (the "License"); you may not use this file except in
%%   compliance with the License. You may obtain a copy of the License at
%%   http://www.mozilla.org/MPL/
%%
%%   Software distributed under the License is distributed on an "AS IS"
%%   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
%%   License for the specific language governing rights and limitations
%%   under the License.
%%
%%   The Original Code is RabbitMQ.
%%
%%   The Initial Developers of the Original Code are LShift Ltd,
%%   Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd.
%%
%%   Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd,
%%   Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd
%%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
%%   Technologies LLC, and Rabbit Technologies Ltd.
%%
%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
%%   Ltd. Portions created by Cohesive Financial Technologies LLC are
%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
%%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
%%   (C) 2007-2009 Rabbit Technologies Ltd.
%%
%%   All Rights Reserved.
%%
%%   Contributor(s): ______________________________________.
%%

-module(rabbit_plugin_activator).

-export([start/0, stop/0]).

-define(DefaultPluginDir, "plugins").
-define(DefaultUnpackedPluginDir, "priv/plugins").
-define(DefaultRabbitEBin, "ebin").
-define(BaseApps, [rabbit]).

%%----------------------------------------------------------------------------

start() ->
    %% Ensure Rabbit is loaded so we can access it's environment
    application:load(rabbit),

    %% Determine our various directories
    PluginDir         = get_env(plugins_dir,        ?DefaultPluginDir),
    UnpackedPluginDir = get_env(plugins_expand_dir, ?DefaultUnpackedPluginDir),
    RabbitEBin        = get_env(rabbit_ebin,        ?DefaultRabbitEBin),

    RootName = RabbitEBin ++ "/rabbit",

    %% Unpack any .ez plugins
    unpack_ez_plugins(PluginDir, UnpackedPluginDir),

    %% Build a list of required apps based on the fixed set, and any plugins
    RequiredApps = ?BaseApps ++
        find_plugins(PluginDir) ++
        find_plugins(UnpackedPluginDir),

    %% Build the entire set of dependencies - this will load the
    %% applications along the way
    AllApps = case catch sets:to_list(expand_dependencies(RequiredApps)) of
                  {failed_to_load_app, App, Err} -> 
                      error("failed to load application ~s:~n~p", [App, Err]);
                  AppList ->
                      AppList
              end,
    AppVersions = [determine_version(App) || App <- AllApps],
    {rabbit, RabbitVersion} = proplists:lookup(rabbit, AppVersions),

    %% Build the overall release descriptor
    RDesc = {release, 
             {"rabbit", RabbitVersion}, 
             {erts, erlang:system_info(version)},
             AppVersions},

    %% Write it out to ebin/rabbit.rel
    file:write_file(RootName ++ ".rel", io_lib:format("~p.~n", [RDesc])),

    %% Compile the script
    ScriptFile = RootName ++ ".script",
    case systools:make_script(RootName, [local, silent]) of
        {ok, Module, Warnings} -> 
            %% This gets lots of spurious no-source warnings when we
            %% have .ez files, so we want to supress them to prevent
            %% hiding real issues.
            WarningStr = Module:format_warning(
                           [W || W <- Warnings, 
                                 case W of 
                                     {warning, {source_not_found, _}} -> false; 
                                     _                                -> true 
                                 end]),
            case length(WarningStr) of
                0 -> ok;
                _ -> io:format("~s", [WarningStr])
            end,
            ok;
        {error, Module, Error} ->
            error("generation of boot script file ~s failed:~n~s",
                  [ScriptFile, Module:format_error(Error)])
    end,

    case post_process_script(ScriptFile) of
        ok -> ok;
        {error, Reason} ->
            error("post processing of boot script file ~s failed:~n~w",
                  [ScriptFile, Reason])
    end,
    case systools:script2boot(RootName) of
        ok    -> ok;
        error -> error("failed to compile boot script file ~s", [ScriptFile])
    end,
    halt(),
    ok.

stop() ->
    ok.

get_env(Key, Default) ->
    case application:get_env(rabbit, Key) of
        {ok, V} -> V;
        _       -> Default
    end.

determine_version(App) ->
    application:load(App), 
    {ok, Vsn} = application:get_key(App, vsn), 
    {App, Vsn}.

assert_dir(Dir) ->
    case filelib:is_dir(Dir) of
        true  -> ok;
        false -> ok = filelib:ensure_dir(Dir),
                 ok = file:make_dir(Dir)
    end.

delete_dir(Dir) ->
    case filelib:is_dir(Dir) of
        true ->
            case file:list_dir(Dir) of
                {ok, Files} ->
                    [case Dir ++ "/" ++ F of
                         Fn ->
                             case filelib:is_dir(Fn) and not(is_symlink(Fn)) of
                                 true  -> delete_dir(Fn);
                                 false -> file:delete(Fn)
                             end
                     end || F <- Files]
            end,
            ok = file:del_dir(Dir);
        false ->
            ok
    end.

is_symlink(Name) ->
    case file:read_link(Name) of
        {ok, _} -> true;
        _       -> false
    end.

unpack_ez_plugins(PluginSrcDir, PluginDestDir) ->
    %% Eliminate the contents of the destination directory
    delete_dir(PluginDestDir),

    assert_dir(PluginDestDir),
    [unpack_ez_plugin(PluginName, PluginDestDir) ||
        PluginName <- filelib:wildcard(PluginSrcDir ++ "/*.ez")].

unpack_ez_plugin(PluginFn, PluginDestDir) ->
    zip:unzip(PluginFn, [{cwd, PluginDestDir}]),
    ok.

find_plugins(PluginDir) ->
    [prepare_dir_plugin(PluginName) ||
        PluginName <- filelib:wildcard(PluginDir ++ "/*/ebin/*.app")].

prepare_dir_plugin(PluginAppDescFn) ->
    %% Add the plugin ebin directory to the load path
    PluginEBinDirN = filename:dirname(PluginAppDescFn),
    code:add_path(PluginEBinDirN),

    %% We want the second-last token
    NameTokens = string:tokens(PluginAppDescFn,"/."),
    PluginNameString = lists:nth(length(NameTokens) - 1, NameTokens),
    list_to_atom(PluginNameString).

expand_dependencies(Pending) ->
    expand_dependencies(sets:new(), Pending).
expand_dependencies(Current, []) ->
    Current;
expand_dependencies(Current, [Next|Rest]) ->
    case sets:is_element(Next, Current) of
        true ->
            expand_dependencies(Current, Rest);
        false ->
            case application:load(Next) of
                ok ->
                    ok;
                {error, {already_loaded, _}} ->
                    ok;
                {error, Reason} ->
                    throw({failed_to_load_app, Next, Reason})
            end,
            {ok, Required} = application:get_key(Next, applications),
            Unique = [A || A <- Required, not(sets:is_element(A, Current))],
            expand_dependencies(sets:add_element(Next, Current), Rest ++ Unique)
    end.

post_process_script(ScriptFile) ->
    case file:consult(ScriptFile) of
        {ok, [{script, Name, Entries}]} ->
            NewEntries = process_entries(Entries),
            case file:open(ScriptFile, [write]) of
                {ok, Fd} ->
                    io:format(Fd, "%% script generated at ~w ~w~n~p.~n",
                              [date(), time(), {script, Name, NewEntries}]),
                    file:close(Fd),
                    ok;
                {error, OReason} ->
                    {error, {failed_to_open_script_file_for_writing, OReason}}
            end;
        {error, Reason} ->
            {error, {failed_to_load_script, Reason}}
    end.

process_entries([]) -> 
    [];
process_entries([Entry = {apply,{application,start_boot,[stdlib,permanent]}} |
                 Rest]) ->
    [Entry, {apply,{rabbit,prepare,[]}} | Rest];
process_entries([Entry|Rest]) ->
    [Entry | process_entries(Rest)].

error(Fmt, Args) ->
    io:format("ERROR: " ++ Fmt ++ "~n", Args),
    halt(1).