Use lazy initialization for the default grpc client

This avoids using a public global variable. It allows us to initialize
the default client a bit later (outside of init()). That way we can e.g.
properly initialize the in-memory registry.

ocis-pkg/service/grpc/service.go

@@ -2,6 +2,7 @@ package grpc
 
 import (
 	"strings"
+	"sync"
 	"time"
 
 	mgrpcc "github.com/go-micro/plugins/v4/client/grpc"
@@ -15,16 +16,25 @@ import (
 )
 
 // DefaultClient is a custom oCIS grpc configured client.
-var DefaultClient = getDefaultGrpcClient()
+var (
+	defaultClient client.Client
+	once          sync.Once
+)
+
+func DefaultClient() client.Client {
+	return getDefaultGrpcClient()
+}
 
 func getDefaultGrpcClient() client.Client {
+	once.Do(func() {
+		reg := registry.GetRegistry()
 
-	reg := registry.GetRegistry()
-
-	return mgrpcc.NewClient(
-		client.Registry(reg),
-		client.Wrap(mbreaker.NewClientWrapper()),
-	)
+		defaultClient = mgrpcc.NewClient(
+			client.Registry(reg),
+			client.Wrap(mbreaker.NewClientWrapper()),
+		)
+	})
+	return defaultClient
 }
 
 // Service simply wraps the go-micro grpc service.
@@ -40,7 +50,7 @@ func NewService(opts ...Option) Service {
 		// first add a server because it will reset any options
 		micro.Server(mgrpcs.NewServer()),
 		// also add a client that can be used after initializing the service
-		micro.Client(DefaultClient),
+		micro.Client(DefaultClient()),
 		micro.Address(sopts.Address),
 		micro.Name(strings.Join([]string{sopts.Namespace, sopts.Name}, ".")),
 		micro.Version(sopts.Version),

services/graph/pkg/service/v0/drives.go

@@ -168,7 +168,7 @@ func (g Graph) GetSingleDrive(w http.ResponseWriter, r *http.Request) {
 }
 
 func canCreateSpace(ctx context.Context, ownPersonalHome bool) bool {
-	s := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient)
+	s := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient())
 
 	pr, err := s.GetPermissionByID(ctx, &settingssvc.GetPermissionByIDRequest{
 		PermissionId: settingsServiceExt.CreateSpacePermissionID,
@@ -420,7 +420,7 @@ func (g Graph) ListStorageSpacesWithFilters(ctx context.Context, filters []*stor
 	client := g.GetGatewayClient()
 
 	permissions := make(map[string]struct{}, 1)
-	s := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient)
+	s := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient())
 
 	_, err := s.GetPermissionByID(ctx, &settingssvc.GetPermissionByIDRequest{
 		PermissionId: settingsServiceExt.ListAllSpacesPermissionID,
@@ -700,7 +700,7 @@ func getQuota(quota *libregraph.Quota, defaultQuota string) *storageprovider.Quo
 }
 
 func canSetSpaceQuota(ctx context.Context, user *userv1beta1.User) (bool, error) {
-	settingsService := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient)
+	settingsService := settingssvc.NewPermissionService("com.owncloud.api.settings", grpc.DefaultClient())
 	_, err := settingsService.GetPermissionByID(ctx, &settingssvc.GetPermissionByIDRequest{PermissionId: settingsServiceExt.SetSpaceQuotaPermissionID})
 	if err != nil {
 		merror := merrors.FromError(err)

services/graph/pkg/service/v0/service.go

@@ -137,7 +137,7 @@ func NewService(opts ...Option) Service {
 	}
 
 	if options.RoleService == nil {
-		svc.roleService = settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient)
+		svc.roleService = settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient())
 	} else {
 		svc.roleService = options.RoleService
 	}

services/ocs/pkg/service/v0/service.go

@@ -38,7 +38,7 @@ func NewService(opts ...Option) Service {
 
 	roleService := options.RoleService
 	if roleService == nil {
-		roleService = settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient)
+		roleService = settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient())
 	}
 	roleManager := options.RoleManager
 	if roleManager == nil {

services/proxy/pkg/command/server.go

@@ -127,7 +127,7 @@ func Server(cfg *config.Config) *cli.Command {
 }
 
 func loadMiddlewares(ctx context.Context, logger log.Logger, cfg *config.Config) alice.Chain {
-	rolesClient := settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient)
+	rolesClient := settingssvc.NewRoleService("com.owncloud.api.settings", grpc.DefaultClient())
 	revaClient, err := cs3.GetGatewayServiceClient(cfg.Reva.Address)
 	var userProvider backend.UserBackend
 	switch cfg.AccountBackend {
@@ -145,7 +145,7 @@ func loadMiddlewares(ctx context.Context, logger log.Logger, cfg *config.Config)
 		logger.Fatal().Msgf("Invalid accounts backend type '%s'", cfg.AccountBackend)
 	}
 
-	storeClient := storesvc.NewStoreService("com.owncloud.api.store", grpc.DefaultClient)
+	storeClient := storesvc.NewStoreService("com.owncloud.api.store", grpc.DefaultClient())
 	if err != nil {
 		logger.Error().Err(err).
 			Str("gateway", cfg.Reva.Address).

services/search/pkg/command/index.go

@@ -37,7 +37,7 @@ func Index(cfg *config.Config) *cli.Command {
 			return parser.ParseConfig(cfg)
 		},
 		Action: func(c *cli.Context) error {
-			client := searchsvc.NewSearchProviderService("com.owncloud.api.search", grpc.DefaultClient)
+			client := searchsvc.NewSearchProviderService("com.owncloud.api.search", grpc.DefaultClient())
 			_, err := client.IndexSpace(context.Background(), &searchsvc.IndexSpaceRequest{
 				SpaceId: c.String("space"),
 				UserId:  c.String("user"),

services/webdav/pkg/service/v0/service.go

@@ -69,8 +69,8 @@ func NewService(opts ...Option) (Service, error) {
 		config:           conf,
 		log:              options.Logger,
 		mux:              m,
-		searchClient:     searchsvc.NewSearchProviderService("com.owncloud.api.search", grpc.DefaultClient),
-		thumbnailsClient: thumbnailssvc.NewThumbnailService("com.owncloud.api.thumbnails", grpc.DefaultClient),
+		searchClient:     searchsvc.NewSearchProviderService("com.owncloud.api.search", grpc.DefaultClient()),
+		thumbnailsClient: thumbnailssvc.NewThumbnailService("com.owncloud.api.thumbnails", grpc.DefaultClient()),
 		revaClient:       gwc,
 	}