Plugins: add a way to mark plugins as bundling all deps

deps/rabbit/src/rabbit_plugins.erl

@@ -18,6 +18,7 @@
 -export([which_plugin/1]).
 
 % Export for testing purpose.
+-export([does_bundle_dependencies/1, does_not_bundle_dependencies/1]).
 -export([is_version_supported/2, validate_plugins/2]).
 %%----------------------------------------------------------------------------
 
@@ -216,10 +217,18 @@ read_enabled(PluginsFile) ->
 
 dependencies(Reverse, Sources, AllPlugins) ->
     {ok, G} = rabbit_misc:build_acyclic_graph(
-                fun ({App, _Deps}) -> [{App, App}] end,
-                fun ({App,  Deps}) -> [{App, Dep} || Dep <- Deps] end,
-                [{Name, Deps} || #plugin{name         = Name,
-                                         dependencies = Deps} <- AllPlugins]),
+                %% Every plugin becomes a DAG vertex
+                fun ({App, _BundlesDeps, _Deps}) -> [{App, App}] end,
+                %% Only those plugins that do not bundle their dependencies are used to populate the
+                %% edges of the dependency DAG
+                fun ({App,  BundlesDeps, Deps}) -> [{App, Dep} || Dep <- Deps, not BundlesDeps] end,
+                %% the value returned here are passed to the VertexFun and EdgeFun functions
+                [{Name, BundlesDeps, Deps} ||
+                    #plugin{
+                      name  = Name,
+                      ez_bundles_dependencies = BundlesDeps,
+                      dependencies = Deps
+                    } <- AllPlugins]),
     Dests = case Reverse of
                 false -> digraph_utils:reachable(Sources, G);
                 true  -> digraph_utils:reaching(Sources, G)
@@ -261,9 +270,21 @@ is_plugin_provided_by_otp(#plugin{name = eldap}) ->
 is_plugin_provided_by_otp(_) ->
     false.
 
+does_bundle_dependencies(#plugin{ez_bundles_dependencies = true}) ->
+    true;
+does_bundle_dependencies(_) ->
+    false.
+
+does_not_bundle_dependencies(Plugin) ->
+    not does_bundle_dependencies(Plugin).
+
 %% Make sure we don't list OTP apps in here, and also that we detect
 %% missing dependencies.
-ensure_dependencies(Plugins) ->
+ensure_dependencies(Plugins0) ->
+    %% Filter out plugins marked as bundling dependencies: they
+    %% are packaged as single EZ files and this dependency validation
+    %% does not make sense for them. MK.
+    Plugins = lists:filter(fun does_not_bundle_dependencies/1, Plugins0),
     Names = plugin_names(Plugins),
     NotThere = [Dep || #plugin{dependencies = Deps} <- Plugins,
                        Dep                          <- Deps,
@@ -278,9 +299,10 @@ ensure_dependencies(Plugins) ->
                                          end, Deps)],
               throw({error, {missing_dependencies, Missing, Blame}})
     end,
+    %% Unlike with the validation above, all plugins must be considered here. MK.
     [P#plugin{dependencies = Deps -- OTP,
               extra_dependencies = Deps -- (Deps -- OTP)}
-     || P = #plugin{dependencies = Deps} <- Plugins].
+     || P = #plugin{dependencies = Deps} <- Plugins0].
 
 is_loadable(App) ->
     case application:load(App) of
@@ -594,10 +616,21 @@ mkplugin(Name, Props, Type, Location) ->
     Dependencies = proplists:get_value(applications, Props, []),
     BrokerVersions = proplists:get_value(broker_version_requirements, Props, []),
     DepsVersions = proplists:get_value(dependency_version_requirements, Props, []),
-    #plugin{name = Name, version = Version, description = Description,
-            dependencies = Dependencies, location = Location, type = Type,
-            broker_version_requirements = BrokerVersions,
-            dependency_version_requirements = DepsVersions}.
+    %% Plugins that bundle their dependencies (into the same .ez file)
+    %% are supposed to set this field to `true`. MK.
+    BundlesDependencies = proplists:get_value(ez_bundles_dependencies, Props, false),
+
+    #plugin{
+        name = Name,
+        version = Version,
+        description = Description,
+        dependencies = Dependencies,
+        location = Location,
+        type = Type,
+        broker_version_requirements = BrokerVersions,
+        dependency_version_requirements = DepsVersions,
+        ez_bundles_dependencies = BundlesDependencies
+    }.
 
 read_app_file(EZ) ->
     case zip:list_dir(EZ) of

deps/rabbit_common/include/rabbit.hrl

@@ -145,8 +145,13 @@
                  %% e.g. [{rabbitmq_management, ["3.5.7", "3.6.1"]},
                  %%       {rabbitmq_federation, ["3.5.7", "3.6.1"]},
                  %%       {rabbitmq_email,      ["0.1.0"]}]
-                 dependency_version_requirements, %% [{atom(), [string()]}]
-                 extra_dependencies %% string()
+                 %%
+                 %% [{atom(), [string()]}]
+                 dependency_version_requirements,
+                 %% string()
+                 extra_dependencies,
+                 %% boolean()
+                 ez_bundles_dependencies = false
                 }).
 
 %% used to track connections across virtual hosts