Merge pull request #6432 from dmcgowan/fix-introspection-service

services/introspection: fix plugin caching to show grpc plugins

plugin/context.go

@@ -132,9 +132,19 @@ func (ps *Set) Get(t Type) (interface{}, error) {
 	return nil, fmt.Errorf("no plugins registered for %s: %w", t, errdefs.ErrNotFound)
 }
 
+// GetAll returns all initialized plugins
+func (ps *Set) GetAll() []*Plugin {
+	return ps.ordered
+}
+
+// Plugins returns plugin set
+func (i *InitContext) Plugins() *Set {
+	return i.plugins
+}
+
 // GetAll plugins in the set
 func (i *InitContext) GetAll() []*Plugin {
-	return i.plugins.ordered
+	return i.plugins.GetAll()
 }
 
 // GetByID returns the plugin of the given type and ID

services/introspection/local.go

@@ -41,12 +41,9 @@ func init() {
 		ID:       services.IntrospectionService,
 		Requires: []plugin.Type{},
 		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
-			// this service works by using the plugin context up till the point
-			// this service is initialized. Since we require this service last,
-			// it should provide the full set of plugins.
-			pluginsPB := pluginsToPB(ic.GetAll())
+			// this service fetches all plugins through the plugin set of the plugin context
 			return &Local{
-				plugins: pluginsPB,
+				plugins: ic.Plugins(),
 				root:    ic.Root,
 			}, nil
 		},
@@ -55,19 +52,19 @@ func init() {
 
 // Local is a local implementation of the introspection service
 type Local struct {
-	mu      sync.Mutex
-	plugins []api.Plugin
-	root    string
+	mu          sync.Mutex
+	root        string
+	plugins     *plugin.Set
+	pluginCache []api.Plugin
 }
 
 var _ = (api.IntrospectionClient)(&Local{})
 
 // UpdateLocal updates the local introspection service
-func (l *Local) UpdateLocal(root string, plugins []api.Plugin) {
+func (l *Local) UpdateLocal(root string) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 	l.root = root
-	l.plugins = plugins
 }
 
 // Plugins returns the locally defined plugins
@@ -95,7 +92,11 @@ func (l *Local) Plugins(ctx context.Context, req *api.PluginsRequest, _ ...grpc.
 func (l *Local) getPlugins() []api.Plugin {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	return l.plugins
+	plugins := l.plugins.GetAll()
+	if l.pluginCache == nil || len(plugins) != len(l.pluginCache) {
+		l.pluginCache = pluginsToPB(plugins)
+	}
+	return l.pluginCache
 }
 
 // Server returns the local server information

services/introspection/service.go

@@ -31,11 +31,8 @@ func init() {
 	plugin.Register(&plugin.Registration{
 		Type:     plugin.GRPCPlugin,
 		ID:       "introspection",
-		Requires: []plugin.Type{"*"},
+		Requires: []plugin.Type{plugin.ServicePlugin},
 		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
-			// this service works by using the plugin context up till the point
-			// this service is initialized. Since we require this service last,
-			// it should provide the full set of plugins.
 			plugins, err := ic.GetByType(plugin.ServicePlugin)
 			if err != nil {
 				return nil, err
@@ -50,13 +47,11 @@ func init() {
 				return nil, err
 			}
 
-			allPluginsPB := pluginsToPB(ic.GetAll())
-
 			localClient, ok := i.(*Local)
 			if !ok {
 				return nil, errors.New("Could not create a local client for introspection service")
 			}
-			localClient.UpdateLocal(ic.Root, allPluginsPB)
+			localClient.UpdateLocal(ic.Root)
 
 			return &server{
 				local: localClient,