Modules: Add registry (#70859)

pkg/modules/dependencies.go

@@ -0,0 +1,11 @@
+package modules
+
+const (
+	// All includes all modules necessary for Grafana to run as a standalone application.
+	All string = "all"
+)
+
+// dependencyMap defines Module Targets => Dependencies
+var dependencyMap = map[string][]string{
+	All: {},
+}

pkg/modules/listener.go

@@ -21,11 +21,19 @@ func newServiceListener(logger log.Logger, s *service) *serviceListener {
 }
 
 func (l *serviceListener) Healthy() {
-	l.log.Info("All modules healthy")
+	l.log.Info("All modules healthy", "modules", l.moduleNames())
 }
 
 func (l *serviceListener) Stopped() {
-	l.log.Info("All modules stopped")
+	l.log.Info("All modules stopped", "modules", l.moduleNames())
+}
+
+func (l *serviceListener) moduleNames() []string {
+	var ms []string
+	for m := range l.service.serviceMap {
+		ms = append(ms, m)
+	}
+	return ms
 }
 
 func (l *serviceListener) Failure(service services.Service) {
@@ -35,7 +43,7 @@ func (l *serviceListener) Failure(service services.Service) {
 	}
 
 	// log which module failed
-	for module, s := range l.service.ServiceMap {
+	for module, s := range l.service.serviceMap {
 		if s == service {
 			if errors.Is(service.FailureCase(), modules.ErrStopProcess) {
 				l.log.Info("Received stop signal via return error", "module", module, "err", service.FailureCase())

pkg/modules/modules.go

@@ -11,11 +11,6 @@ import (
 	"github.com/grafana/grafana/pkg/setting"
 )
 
-// List of available targets.
-const (
-	All string = "all"
-)
-
 type Engine interface {
 	Init(context.Context) error
 	Run(context.Context) error
@@ -23,8 +18,8 @@ type Engine interface {
 }
 
 type Manager interface {
-	RegisterModule(name string, initFn func() (services.Service, error), deps ...string)
-	RegisterInvisibleModule(name string, initFn func() (services.Service, error), deps ...string)
+	RegisterModule(name string, initFn func() (services.Service, error))
+	RegisterInvisibleModule(name string, initFn func() (services.Service, error))
 }
 
 var _ Engine = (*service)(nil)
@@ -35,11 +30,10 @@ type service struct {
 	cfg     *setting.Cfg
 	log     log.Logger
 	targets []string
-	dependencyMap map[string][]string
 
-	ModuleManager  *modules.Manager
-	ServiceManager *services.Manager
-	ServiceMap     map[string]services.Service
+	moduleManager  *modules.Manager
+	serviceManager *services.Manager
+	serviceMap     map[string]services.Service
 }
 
 func ProvideService(cfg *setting.Cfg) *service {
@@ -49,10 +43,9 @@ func ProvideService(cfg *setting.Cfg) *service {
 		cfg:     cfg,
 		log:     logger,
 		targets: cfg.Target,
-		dependencyMap: map[string][]string{},
 
-		ModuleManager: modules.NewManager(logger),
-		ServiceMap:    map[string]services.Service{},
+		moduleManager: modules.NewManager(logger),
+		serviceMap:    map[string]services.Service{},
 	}
 }
 
@@ -60,30 +53,27 @@ func ProvideService(cfg *setting.Cfg) *service {
 func (m *service) Init(_ context.Context) error {
 	var err error
 
-	// module registration
-	m.RegisterModule(All, nil)
-
-	for mod, targets := range m.dependencyMap {
-		if err := m.ModuleManager.AddDependency(mod, targets...); err != nil {
+	for mod, targets := range dependencyMap {
+		if err := m.moduleManager.AddDependency(mod, targets...); err != nil {
 			return err
 		}
 	}
 
-	m.ServiceMap, err = m.ModuleManager.InitModuleServices(m.targets...)
+	m.serviceMap, err = m.moduleManager.InitModuleServices(m.targets...)
 	if err != nil {
 		return err
 	}
 
 	// if no modules are registered, we don't need to start the service manager
-	if len(m.ServiceMap) == 0 {
+	if len(m.serviceMap) == 0 {
 		return nil
 	}
 
 	var svcs []services.Service
-	for _, s := range m.ServiceMap {
+	for _, s := range m.serviceMap {
 		svcs = append(svcs, s)
 	}
-	m.ServiceManager, err = services.NewManager(svcs...)
+	m.serviceManager, err = services.NewManager(svcs...)
 
 	return err
 }
@@ -93,27 +83,27 @@ func (m *service) Run(ctx context.Context) error {
 	// we don't need to continue if no modules are registered.
 	// this behavior may need to change if dskit services replace the
 	// current background service registry.
-	if len(m.ServiceMap) == 0 {
+	if len(m.serviceMap) == 0 {
 		m.log.Warn("No modules registered...")
 		<-ctx.Done()
 		return nil
 	}
 
 	listener := newServiceListener(m.log, m)
-	m.ServiceManager.AddListener(listener)
+	m.serviceManager.AddListener(listener)
 
 	// wait until a service fails or stop signal was received
-	err := m.ServiceManager.StartAsync(ctx)
+	err := m.serviceManager.StartAsync(ctx)
 	if err != nil {
 		return err
 	}
 
-	err = m.ServiceManager.AwaitStopped(ctx)
+	err = m.serviceManager.AwaitStopped(ctx)
 	if err != nil {
 		return err
 	}
 
-	failed := m.ServiceManager.ServicesByState()[services.Failed]
+	failed := m.serviceManager.ServicesByState()[services.Failed]
 	for _, f := range failed {
 		// the service listener will log error details for all modules that failed,
 		// so here we return the first error that is not ErrStopProcess
@@ -127,26 +117,24 @@ func (m *service) Run(ctx context.Context) error {
 
 // Shutdown stops all modules and waits for them to stop.
 func (m *service) Shutdown(ctx context.Context) error {
-	if m.ServiceManager == nil {
+	if m.serviceManager == nil {
 		m.log.Debug("No modules registered, nothing to stop...")
 		return nil
 	}
-	m.ServiceManager.StopAsync()
+	m.serviceManager.StopAsync()
 	m.log.Info("Awaiting services to be stopped...")
-	return m.ServiceManager.AwaitStopped(ctx)
+	return m.serviceManager.AwaitStopped(ctx)
 }
 
 // RegisterModule registers a module with the dskit module manager.
-func (m *service) RegisterModule(name string, initFn func() (services.Service, error), deps ...string) {
-	m.ModuleManager.RegisterModule(name, initFn)
-	m.dependencyMap[name] = deps
+func (m *service) RegisterModule(name string, initFn func() (services.Service, error)) {
+	m.moduleManager.RegisterModule(name, initFn)
 }
 
 // RegisterInvisibleModule registers an invisible module with the dskit module manager.
-// Invisible modules are not visible to the user, and are intendent to be used as dependencies.
-func (m *service) RegisterInvisibleModule(name string, initFn func() (services.Service, error), deps ...string) {
-	m.ModuleManager.RegisterModule(name, initFn, modules.UserInvisibleModule)
-	m.dependencyMap[name] = deps
+// Invisible modules are not visible to the user, and are intended to be used as dependencies.
+func (m *service) RegisterInvisibleModule(name string, initFn func() (services.Service, error)) {
+	m.moduleManager.RegisterModule(name, initFn, modules.UserInvisibleModule)
 }
 
 // IsModuleEnabled returns true if the module is enabled.

pkg/modules/registry/registry.go

@@ -0,0 +1,46 @@
+package registry
+
+import (
+	"github.com/grafana/dskit/services"
+
+	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/modules"
+)
+
+type Registry interface{}
+
+type registry struct {
+	moduleManager modules.Manager
+	log           log.Logger
+}
+
+func ProvideRegistry(
+	moduleManager modules.Manager,
+) *registry {
+	return newRegistry(
+		log.New("modules.registry"),
+		moduleManager,
+	)
+}
+
+func newRegistry(logger log.Logger, moduleManager modules.Manager, svcs ...services.NamedService) *registry {
+	r := &registry{
+		log:           logger,
+		moduleManager: moduleManager,
+	}
+
+	// Register (invisible) modules which act solely as dependencies to module targets
+	for _, svc := range svcs {
+		s := svc
+		logger.Debug("Registering invisible module", "name", s.ServiceName())
+		r.moduleManager.RegisterInvisibleModule(s.ServiceName(), func() (services.Service, error) {
+			return s, nil
+		})
+	}
+
+	// Register module targets
+	logger.Debug("Registering module", "name", modules.All)
+	r.moduleManager.RegisterModule(modules.All, nil)
+
+	return r
+}

pkg/modules/registry/registry_test.go

@@ -0,0 +1,34 @@
+package registry
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/grafana/dskit/services"
+
+	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/modules"
+)
+
+func TestRegistry(t *testing.T) {
+	var registeredInvisibleModules []string
+	var registeredModules []string
+
+	moduleManager := &modules.MockModuleManager{
+		RegisterModuleFunc: func(name string, initFn func() (services.Service, error)) {
+			registeredModules = append(registeredModules, name)
+		},
+		RegisterInvisibleModuleFunc: func(name string, initFn func() (services.Service, error)) {
+			registeredInvisibleModules = append(registeredInvisibleModules, name)
+		},
+	}
+
+	mockSvcName := "test-registry"
+	mockSvc := modules.NewMockNamedService(mockSvcName)
+
+	r := newRegistry(log.New("modules.registry"), moduleManager, mockSvc)
+	require.NotNil(t, r)
+	require.Equal(t, []string{mockSvcName}, registeredInvisibleModules)
+	require.Equal(t, []string{modules.All}, registeredModules)
+}

pkg/modules/registry/wire.go

@@ -0,0 +1,8 @@
+package registry
+
+import "github.com/google/wire"
+
+var WireSet = wire.NewSet(
+	ProvideRegistry,
+	wire.Bind(new(Registry), new(*registry)),
+)

pkg/modules/util.go

@@ -1,5 +1,58 @@
 package modules
 
+import (
+	"context"
+
+	"github.com/grafana/dskit/services"
+)
+
+var _ Manager = (*MockModuleManager)(nil)
+var _ Engine = (*MockModuleEngine)(nil)
+
+type MockModuleManager struct {
+	RegisterModuleFunc          func(name string, initFn func() (services.Service, error))
+	RegisterInvisibleModuleFunc func(name string, initFn func() (services.Service, error))
+}
+
+func (m *MockModuleManager) RegisterModule(name string, initFn func() (services.Service, error)) {
+	if m.RegisterModuleFunc != nil {
+		m.RegisterModuleFunc(name, initFn)
+	}
+}
+
+func (m *MockModuleManager) RegisterInvisibleModule(name string, initFn func() (services.Service, error)) {
+	if m.RegisterInvisibleModuleFunc != nil {
+		m.RegisterInvisibleModuleFunc(name, initFn)
+	}
+}
+
+type MockModuleEngine struct {
+	InitFunc     func(context.Context) error
+	RunFunc      func(context.Context) error
+	ShutdownFunc func(context.Context) error
+}
+
+func (m *MockModuleEngine) Init(ctx context.Context) error {
+	if m.InitFunc != nil {
+		return m.InitFunc(ctx)
+	}
+	return nil
+}
+
+func (m *MockModuleEngine) Run(ctx context.Context) error {
+	if m.RunFunc != nil {
+		return m.RunFunc(ctx)
+	}
+	return nil
+}
+
+func (m *MockModuleEngine) Shutdown(ctx context.Context) error {
+	if m.ShutdownFunc != nil {
+		return m.ShutdownFunc(ctx)
+	}
+	return nil
+}
+
 func stringsContain(values []string, search string) bool {
 	for _, v := range values {
 		if search == v {
@@ -9,3 +62,14 @@ func stringsContain(values []string, search string) bool {
 
 	return false
 }
+
+type MockNamedService struct {
+	*services.BasicService
+}
+
+func NewMockNamedService(name string) *MockNamedService {
+	startFn := func(_ context.Context) error { return nil }
+	return &MockNamedService{
+		BasicService: services.NewIdleService(startFn, nil).WithName(name),
+	}
+}

pkg/modules/wire.go

@@ -1,6 +1,8 @@
 package modules
 
-import "github.com/google/wire"
+import (
+	"github.com/google/wire"
+)
 
 var WireSet = wire.NewSet(
 	ProvideService,

pkg/server/server.go

@@ -19,6 +19,7 @@ import (
 	"github.com/grafana/grafana/pkg/infra/metrics"
 	"github.com/grafana/grafana/pkg/infra/usagestats/statscollector"
 	"github.com/grafana/grafana/pkg/modules"
+	moduleRegistry "github.com/grafana/grafana/pkg/modules/registry"
 	"github.com/grafana/grafana/pkg/registry"
 	"github.com/grafana/grafana/pkg/services/accesscontrol"
 	"github.com/grafana/grafana/pkg/services/provisioning"
@@ -40,6 +41,7 @@ func New(opts Options, cfg *setting.Cfg, httpServer *api.HTTPServer, roleRegistr
 	provisioningService provisioning.ProvisioningService, backgroundServiceProvider registry.BackgroundServiceRegistry,
 	usageStatsProvidersRegistry registry.UsageStatsProvidersRegistry, statsCollectorService *statscollector.Service,
 	moduleService modules.Engine,
+	_ moduleRegistry.Registry, // imported to invoke initialization via Wire
 ) (*Server, error) {
 	statsCollectorService.RegisterProviders(usageStatsProvidersRegistry.GetServices())
 	s, err := newServer(opts, cfg, httpServer, roleRegistry, provisioningService, backgroundServiceProvider, moduleService)

pkg/server/wire.go

@@ -31,6 +31,7 @@ import (
 	"github.com/grafana/grafana/pkg/middleware/csrf"
 	"github.com/grafana/grafana/pkg/middleware/loggermw"
 	"github.com/grafana/grafana/pkg/modules"
+	moduleRegistry "github.com/grafana/grafana/pkg/modules/registry"
 	pluginDashboards "github.com/grafana/grafana/pkg/plugins/manager/dashboards"
 	"github.com/grafana/grafana/pkg/registry/corekind"
 	"github.com/grafana/grafana/pkg/services/accesscontrol"
@@ -357,6 +358,7 @@ var wireBasicSet = wire.NewSet(
 	wire.Bind(new(oauthserver.OAuth2Server), new(*oasimpl.OAuth2ServiceImpl)),
 	loggermw.Provide,
 	modules.WireSet,
+	moduleRegistry.WireSet,
 	signingkeysimpl.ProvideEmbeddedSigningKeysService,
 	wire.Bind(new(signingkeys.Service), new(*signingkeysimpl.Service)),
 )