WIP: Add private Secret Manager Plugins support to plugin platform (#49544)

* Add protobuf config and generated code, and client wrapper

* wire up loading of secretsmanager plugin, using renderer plugin as a model

* update kvstore provider to check if we should use the grpc plugin. return false always in OSS

* add OSS remote plugin check

* refactor wire gen file

* log which secrets manager is being used

* Fix argument types for remote checker

* Turns out if err != nil, then the result is always nil. Return empty values if there is an error.

* remove duplicate import

* Update pkg/services/secrets/kvstore/kvstore.go

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

* Update pkg/services/secrets/kvstore/kvstore.go

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

* refactor RemotePluginCheck interface to just return the Plugin client directly

* rename struct to something less silly

* Update pkg/plugins/backendplugin/secretsmanagerplugin/secretsmanager.proto

Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

pkg/plugins/manager/loader/initializer/initializer_test.go

@@ -79,6 +79,36 @@ func TestInitializer_Initialize(t *testing.T) {
 		assert.NotNil(t, c)
 	})
 
+	t.Run("secretsmanager", func(t *testing.T) {
+		p := &plugins.Plugin{
+			JSONData: plugins.JSONData{
+				ID:   "test",
+				Type: plugins.SecretsManager,
+				Dependencies: plugins.Dependencies{
+					GrafanaVersion: ">=8.x",
+				},
+				Backend: true,
+			},
+			PluginDir: absCurPath,
+			Class:     plugins.External,
+		}
+
+		i := &Initializer{
+			cfg: plugins.NewCfg(),
+			log: log.NewNopLogger(),
+			backendProvider: &fakeBackendProvider{
+				plugin: p,
+			},
+		}
+
+		err := i.Initialize(context.Background(), p)
+		assert.NoError(t, err)
+
+		c, exists := p.Client()
+		assert.True(t, exists)
+		assert.NotNil(t, c)
+	})
+
 	t.Run("non backend plugin app", func(t *testing.T) {
 		p := &plugins.Plugin{
 			JSONData: plugins.JSONData{

pkg/plugins/manager/manager.go

@@ -24,6 +24,7 @@ var _ plugins.Client = (*PluginManager)(nil)
 var _ plugins.Store = (*PluginManager)(nil)
 var _ plugins.StaticRouteResolver = (*PluginManager)(nil)
 var _ plugins.RendererManager = (*PluginManager)(nil)
+var _ plugins.SecretsPluginManager = (*PluginManager)(nil)
 
 type PluginManager struct {
 	cfg             *plugins.Cfg
@@ -117,6 +118,16 @@ func (m *PluginManager) Renderer() *plugins.Plugin {
 	return nil
 }
 
+func (m *PluginManager) SecretsManager() *plugins.Plugin {
+	for _, p := range m.availablePlugins(context.TODO()) {
+		if p.IsSecretsManager() {
+			return p
+		}
+	}
+
+	return nil
+}
+
 func (m *PluginManager) Routes() []*plugins.StaticRoute {
 	staticRoutes := make([]*plugins.StaticRoute, 0)