resolver: Add NoOpResolver

This is a temporary backward compatibility for case when rpc_endpoint/S3_GW_RPC_ENDPOINT param is empty in config

Signed-off-by: Evgenii Baidakov <[email protected]>

api/resolver/resolver.go

@@ -16,18 +16,23 @@ var (
 	ErrNotFound = errors.New("not found")
 )
 
-// Resolver allows to resolve container id by its name.
-type Resolver struct {
+// Resolver allows to map container ID by container name.
+type Resolver interface {
+	Resolve(ctx context.Context, containerName string) (cid.ID, error)
+}
+
+// NNSResolver allows to resolve container id by its name.
+type NNSResolver struct {
 	reader *rpcNNS.ContractReader
 }
 
-// NewResolver is a constructor for the Resolver.
-func NewResolver(reader *rpcNNS.ContractReader) *Resolver {
-	return &Resolver{reader: reader}
+// NewNNSResolver is a constructor for the NNSResolver.
+func NewNNSResolver(reader *rpcNNS.ContractReader) *NNSResolver {
+	return &NNSResolver{reader: reader}
 }
 
 // Resolve looks up the container id by it's name via NNS contract.
-func (r *Resolver) Resolve(_ context.Context, name string) (cid.ID, error) {
+func (r *NNSResolver) Resolve(_ context.Context, name string) (cid.ID, error) {
 	var result cid.ID
 
 	items, err := r.reader.GetRecords(nnsContainerDomain(name), rpcNNS.TXT)
@@ -48,3 +53,17 @@ func (r *Resolver) Resolve(_ context.Context, name string) (cid.ID, error) {
 func nnsContainerDomain(name string) string {
 	return fmt.Sprintf("%s.%s", name, defaultZone)
 }
+
+// NoOpResolver is a special resolver for situation when [NNSResolver] can't be created.
+type NoOpResolver struct {
+}
+
+// NewNoOpResolver is a constructor for the NoOpResolver.
+func NewNoOpResolver() *NoOpResolver {
+	return &NoOpResolver{}
+}
+
+// Resolve always returns [ErrNotFound].
+func (r *NoOpResolver) Resolve(_ context.Context, _ string) (cid.ID, error) {
+	return cid.ID{}, ErrNotFound
+}

cmd/s3-gw/app.go

@@ -57,7 +57,7 @@ type (
 		servers []Server
 
 		metrics        *appMetrics
-		bucketResolver *resolver.Resolver
+		bucketResolver resolver.Resolver
 		services       []*Service
 		settings       *appSettings
 		maxClients     api.MaxClients
@@ -205,6 +205,15 @@ func (a *App) initMetrics() {
 }
 
 func (a *App) initResolver(ctx context.Context) {
+	a.log.Info("rcp endpoint", zap.String("address", a.cfg.GetString(cfgRPCEndpoint)))
+
+	endpoint := a.cfg.GetString(cfgRPCEndpoint)
+	if endpoint == "" {
+		a.log.Warn("rcp endpoint is empty, NoOpResolver is used")
+		a.bucketResolver = resolver.NewNoOpResolver()
+		return
+	}
+
 	cl, err := rpcClient(ctx, a.cfg.GetString(cfgRPCEndpoint))
 	if err != nil {
 		a.log.Fatal("rpcclient", zap.Error(err))
@@ -218,7 +227,7 @@ func (a *App) initResolver(ctx context.Context) {
 	inv := invoker.New(cl, nil)
 	nnsReader := rpcNNS.NewReader(inv, nnsHash)
 
-	a.bucketResolver = resolver.NewResolver(nnsReader)
+	a.bucketResolver = resolver.NewNNSResolver(nnsReader)
 }
 
 // SystemContractHash allows to get system contract hash.