[#872] services/container: Ignore passed routes in load router

Higher level solution for original issue with lost announcements
from single node container.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

cmd/neofs-node/container.go

@@ -228,6 +228,16 @@ func (*morphLoadWriter) Close() error {
 	return nil
 }
 
+type nopLoadWriter struct{}
+
+func (nopLoadWriter) Put(containerSDK.UsedSpaceAnnouncement) error {
+	return nil
+}
+
+func (nopLoadWriter) Close() error {
+	return nil
+}
+
 type remoteLoadAnnounceProvider struct {
 	key *ecdsa.PrivateKey
 
@@ -241,10 +251,15 @@ type remoteLoadAnnounceProvider struct {
 }
 
 func (r *remoteLoadAnnounceProvider) InitRemote(srv loadroute.ServerInfo) (loadcontroller.WriterProvider, error) {
-	if srv == nil || r.netmapKeys.IsLocalKey(srv.PublicKey()) {
+	if srv == nil {
 		return r.deadEndProvider, nil
 	}
 
+	if r.netmapKeys.IsLocalKey(srv.PublicKey()) {
+		// if local => return no-op writer
+		return loadcontroller.SimpleWriterProvider(new(nopLoadWriter)), nil
+	}
+
 	var info client.NodeInfo
 
 	err := client.NodeInfoFromRawNetmapElement(&info, srv)

pkg/services/container/announcement/load/route/placement/calls.go

@@ -1,6 +1,7 @@
 package placementrouter
 
 import (
+	"bytes"
 	"fmt"
 
 	"github.com/nspcc-dev/neofs-api-go/pkg/container"
@@ -30,7 +31,15 @@ func (b *Builder) NextStage(a container.UsedSpaceAnnouncement, passed []loadrout
 			continue
 		}
 
-		res = append(res, placement[i][0])
+		target := placement[i][0]
+
+		if len(passed) == 1 && bytes.Equal(passed[0].PublicKey(), target.PublicKey()) {
+			// add nil element so the announcement will be saved in local memory
+			res = append(res, nil)
+		} else {
+			// add element with remote node to send announcement to
+			res = append(res, target)
+		}
 	}
 
 	return res, nil