fix discover forwarder

Signed-off-by: Artem Glazychev <artem.glazychev@xored.com>

pkg/networkservice/common/discoverforwarder/metadata.go

@@ -1,5 +1,7 @@
 // Copyright (c) 2021 Doc.ai and/or its affiliates.
 //
+// Copyright (c) 2023 Cisco and/or its affiliates.
+//
 // SPDX-License-Identifier: Apache-2.0
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -22,16 +24,21 @@ import (
 	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
 )
 
-type selectedForworderKey struct{}
+type selectedForwarderKey struct{}
+
+type selectedForwarderVal struct {
+	name   string
+	active bool
+}
 
-func loadForwarderName(ctx context.Context) string {
-	v, ok := metadata.Map(ctx, false).Load(selectedForworderKey{})
+func loadForwarder(ctx context.Context) *selectedForwarderVal {
+	v, ok := metadata.Map(ctx, false).Load(selectedForwarderKey{})
 	if !ok {
-		return ""
+		return nil
 	}
-	return v.(string)
+	return v.(*selectedForwarderVal)
 }
 
-func storeForwarderName(ctx context.Context, v string) {
-	metadata.Map(ctx, false).Store(selectedForworderKey{}, v)
+func storeForwarder(ctx context.Context, v *selectedForwarderVal) {
+	metadata.Map(ctx, false).Store(selectedForwarderKey{}, v)
 }

pkg/networkservice/common/discoverforwarder/server.go

@@ -65,11 +65,12 @@ func NewServer(nsClient registry.NetworkServiceRegistryClient, nseClient registr
 	return result
 }
 
+// nolint:gocyclo
 func (d *discoverForwarderServer) Request(ctx context.Context, request *networkservice.NetworkServiceRequest) (*networkservice.Connection, error) {
-	var forwarderName = loadForwarderName(ctx)
+	var forwarder = loadForwarder(ctx)
 	var logger = log.FromContext(ctx).WithField("discoverForwarderServer", "request")
 
-	if forwarderName == "" {
+	if forwarder == nil || !forwarder.active {
 		ns, err := d.discoverNetworkService(ctx, request.GetConnection().GetNetworkService(), request.GetConnection().GetPayload())
 		if err != nil {
 			return nil, err
@@ -117,7 +118,10 @@ func (d *discoverForwarderServer) Request(ctx context.Context, request *networks
 
 			resp, err := next.Server(ctx).Request(clienturlctx.WithClientURL(ctx, u), request.Clone())
 			if err == nil {
-				storeForwarderName(ctx, candidate.Name)
+				storeForwarder(ctx, &selectedForwarderVal{
+					name:   candidate.Name,
+					active: true,
+				})
 				return resp, nil
 			}
 			logger.Errorf("forwarder=%v url=%v returned error=%v", candidate.Name, candidate.Url, err.Error())
@@ -129,18 +133,18 @@ func (d *discoverForwarderServer) Request(ctx context.Context, request *networks
 
 	stream, err := d.nseClient.Find(ctx, &registry.NetworkServiceEndpointQuery{
 		NetworkServiceEndpoint: &registry.NetworkServiceEndpoint{
-			Name: forwarderName,
+			Name: forwarder.name,
 			Url:  d.nsmgrURL,
 		},
 	})
 	if err != nil {
 		logger.Errorf("can not open registry nse stream by forwarder name. Error: %v", err.Error())
-		return nil, errors.Wrapf(err, "failed to find %s on %s", forwarderName, d.nsmgrURL)
+		return nil, errors.Wrapf(err, "failed to find %s on %s", forwarder.name, d.nsmgrURL)
 	}
 
 	nses := registry.ReadNetworkServiceEndpointList(stream)
 	if len(nses) == 0 {
-		storeForwarderName(ctx, "")
+		storeForwarder(ctx, nil)
 		return nil, errors.New("forwarder not found")
 	}
 
@@ -152,27 +156,27 @@ func (d *discoverForwarderServer) Request(ctx context.Context, request *networks
 
 	conn, err := next.Server(ctx).Request(clienturlctx.WithClientURL(ctx, u), request)
 	if err != nil {
-		storeForwarderName(ctx, "")
+		forwarder.active = false
 	}
 	return conn, err
 }
 
 func (d *discoverForwarderServer) Close(ctx context.Context, conn *networkservice.Connection) (*empty.Empty, error) {
-	var forwarderName = loadForwarderName(ctx)
+	var forwarder = loadForwarder(ctx)
 	var logger = log.FromContext(ctx).WithField("discoverForwarderServer", "request")
-	if forwarderName == "" {
+	if forwarder == nil {
 		return nil, errors.New("forwarder is not selected")
 	}
 
 	stream, err := d.nseClient.Find(ctx, &registry.NetworkServiceEndpointQuery{
 		NetworkServiceEndpoint: &registry.NetworkServiceEndpoint{
-			Name: forwarderName,
+			Name: forwarder.name,
 			Url:  d.nsmgrURL,
 		},
 	})
 	if err != nil {
 		logger.Errorf("can not open registry nse stream by forwarder name. Error: %v", err.Error())
-		return nil, errors.Wrapf(err, "failed to find %s on %s", forwarderName, d.nsmgrURL)
+		return nil, errors.Wrapf(err, "failed to find %s on %s", forwarder.name, d.nsmgrURL)
 	}
 
 	nses := registry.ReadNetworkServiceEndpointList(stream)