Revert nsmonitor + add additional checks to prevent random connection…

… closes (#832)

* Add nsmonitor again + add additional checks to prevent random connection closes

Signed-off-by: NikitaSkrynnik <nikita.skrynnik@xored.com>

* fix go linter issues

Signed-off-by: NikitaSkrynnik <nikita.skrynnik@xored.com>

---------

Signed-off-by: NikitaSkrynnik <nikita.skrynnik@xored.com>

pkg/networkservice/chains/forwarder/server.go

@@ -69,6 +69,7 @@ import (
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/mechanisms/vxlan"
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/mechanisms/wireguard"
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/metrics"
+	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/nsmonitor"
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/pinhole"
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/tag"
 	"github.com/networkservicemesh/sdk-vpp/pkg/networkservice/up"
@@ -166,6 +167,7 @@ func NewServer(ctx context.Context, tokenGenerator token.GeneratorFunc, vppConn
 						afxdppinhole.NewClient(),
 						pinhole.NewClient(vppConn, pinhole.WithSharedMutex(pinholeMutex)),
 						recvfd.NewClient(),
+						nsmonitor.NewClient(ctx),
 						sendfd.NewClient(),
 					},
 						opts.clientAdditionalFunctionality...,

pkg/networkservice/nsmonitor/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2022 Cisco and/or its affiliates.
+// Copyright (c) 2022-2024 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -85,7 +85,7 @@ func (r *netNSMonitorClient) Request(ctx context.Context, request *networkservic
 				case <-cancelCtx.Done():
 					return
 				case _, ok := <-deleteCh:
-					if ok {
+					if ok && cancelCtx.Err() == nil {
 						factory.Close(begin.CancelContext(cancelCtx))
 					}
 					return