Don't expand plugins that are already unpacked

This prevents creating unnecessary files when running in embedded
mode, and in development mode it keeps code path clean and compatible
with different interactive tools.

Also some new error conditions are properly handled and logged:
- Failure to unpack an .ez-file
- Missing .app file in plugin directory

1 files changed, 32 insertions, 9 deletions

diff --git a/src/rabbit_plugins.erl b/src/rabbit_plugins.erl
index a5d7de56bb..0a82203678 100644
--- a/src/rabbit_plugins.erl
+++ b/src/rabbit_plugins.erl
@@ -103,7 +103,7 @@ setup() ->
 
 %% @doc Lists the plugins which are currently running.
 active() ->
-    InstalledPlugins = plugin_names(list(plugins_expand_dir())),
+    InstalledPlugins = plugin_names(list(plugins_dist_dir())),
     [App || {App, _, _} <- rabbit_misc:which_applications(),
             lists:member(App, InstalledPlugins)].
 
@@ -200,9 +200,6 @@ prepare_plugins(Enabled) ->
     end,
 
     [prepare_plugin(Plugin, ExpandDir) || Plugin <- WantedPlugins],
-
-    [prepare_dir_plugin(PluginAppDescPath) ||
-        PluginAppDescPath <- filelib:wildcard(ExpandDir ++ "/*/ebin/*.app")],
     Wanted.
 
 clean_plugins(Plugins) ->
@@ -250,11 +247,37 @@ delete_recursively(Fn) ->
         {error, {Path, E}} -> {error, {cannot_delete, Path, E}}
     end.
 
-prepare_plugin(#plugin{type = ez, location = Location}, ExpandDir) ->
-    zip:unzip(Location, [{cwd, ExpandDir}]);
-prepare_plugin(#plugin{type = dir, name = Name, location = Location},
-               ExpandDir) ->
-    rabbit_file:recursive_copy(Location, filename:join([ExpandDir, Name])).
+find_unzipped_app_file(ExpandDir, Files) ->
+    StripComponents = length(filename:split(ExpandDir)),
+    [ X || X <- Files,
+           [_AppName, "ebin", MaybeAppFile] <-
+               [lists:nthtail(StripComponents, filename:split(X))],
+           lists:suffix(".app", MaybeAppFile)
+    ].
+
+prepare_plugin(#plugin{type = ez, name = Name, location = Location}, ExpandDir) ->
+    case zip:unzip(Location, [{cwd, ExpandDir}]) of
+        {ok, Files} ->
+            case find_unzipped_app_file(ExpandDir, Files) of
+                [PluginAppDescPath|_] ->
+                    prepare_dir_plugin(PluginAppDescPath);
+                _ ->
+                    rabbit_log:error("Plugin archive '~s' doesn't contain .app file~n", [Location]),
+                    throw({no_plugin_app_file_in_archive, Name, Location})
+            end;
+        {error, Reason} ->
+            rabbit_log:error("Plugin archive '~s' unpacking failed: ~p~n", [Location, Reason]),
+            throw({plugin_unpack_failed, Name, Location, Reason})
+    end;
+prepare_plugin(#plugin{type = dir, location = Location, name = Name},
+               _ExpandDir) ->
+    case filelib:wildcard(Location ++ "/ebin/*.app") of
+        [PluginAppDescPath|_] ->
+            prepare_dir_plugin(PluginAppDescPath);
+        _ ->
+            rabbit_log:error("Plugin directory '~s' doesn't contain an .app file~n", [Location]),
+            throw({no_plugin_app_file_in_directory, Name, Location})
+    end.
 
 plugin_info({ez, EZ}) ->
     case read_app_file(EZ) of