Fix connstate indication (#732)

Fix the status indication in the client service. The status of the
management server and the signal server was incorrect if the network
connection was broken. Basically the status update was not used by
the management and signal library.

management/client/grpc.go

@@ -4,15 +4,13 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"google.golang.org/grpc/codes"
-	gstatus "google.golang.org/grpc/status"
 	"io"
+	"sync"
 	"time"
 
-	"github.com/cenkalti/backoff/v4"
-	"github.com/netbirdio/netbird/client/system"
-	"github.com/netbirdio/netbird/encryption"
-	"github.com/netbirdio/netbird/management/proto"
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
+
 	log "github.com/sirupsen/logrus"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 	"google.golang.org/grpc"
@@ -20,13 +18,26 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/keepalive"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/netbirdio/netbird/client/system"
+	"github.com/netbirdio/netbird/encryption"
+	"github.com/netbirdio/netbird/management/proto"
 )
 
+// ConnStateNotifier is a wrapper interface of the status recorders
+type ConnStateNotifier interface {
+	MarkManagementDisconnected()
+	MarkManagementConnected()
+}
+
 type GrpcClient struct {
-	key        wgtypes.Key
-	realClient proto.ManagementServiceClient
-	ctx        context.Context
-	conn       *grpc.ClientConn
+	key                   wgtypes.Key
+	realClient            proto.ManagementServiceClient
+	ctx                   context.Context
+	conn                  *grpc.ClientConn
+	connStateCallback     ConnStateNotifier
+	connStateCallbackLock sync.RWMutex
 }
 
 // NewClient creates a new client to Management service
@@ -56,10 +67,11 @@ func NewClient(ctx context.Context, addr string, ourPrivateKey wgtypes.Key, tlsE
 	realClient := proto.NewManagementServiceClient(conn)
 
 	return &GrpcClient{
-		key:        ourPrivateKey,
-		realClient: realClient,
-		ctx:        ctx,
-		conn:       conn,
+		key:                   ourPrivateKey,
+		realClient:            realClient,
+		ctx:                   ctx,
+		conn:                  conn,
+		connStateCallbackLock: sync.RWMutex{},
 	}, nil
 }
 
@@ -68,6 +80,13 @@ func (c *GrpcClient) Close() error {
 	return c.conn.Close()
 }
 
+// SetConnStateListener set the ConnStateNotifier
+func (c *GrpcClient) SetConnStateListener(notifier ConnStateNotifier) {
+	c.connStateCallbackLock.Lock()
+	defer c.connStateCallbackLock.Unlock()
+	c.connStateCallback = notifier
+}
+
 // defaultBackoff is a basic backoff mechanism for general issues
 func defaultBackoff(ctx context.Context) backoff.BackOff {
 	return backoff.WithContext(&backoff.ExponentialBackOff{
@@ -121,7 +140,7 @@ func (c *GrpcClient) Sync(msgHandler func(msg *proto.SyncResponse) error) error
 		}
 
 		log.Infof("connected to the Management Service stream")
-
+		c.notifyConnected()
 		// blocking until error
 		err = c.receiveEvents(stream, *serverPubKey, msgHandler)
 		if err != nil {
@@ -131,6 +150,7 @@ func (c *GrpcClient) Sync(msgHandler func(msg *proto.SyncResponse) error) error
 			// we need this reset because after a successful connection and a consequent error, backoff lib doesn't
 			// reset times and next try will start with a long delay
 			backOff.Reset()
+			c.notifyDisconnected()
 			log.Warnf("disconnected from the Management service but will retry silently. Reason: %v", err)
 			return err
 		}
@@ -298,6 +318,26 @@ func (c *GrpcClient) GetDeviceAuthorizationFlow(serverKey wgtypes.Key) (*proto.D
 	return flowInfoResp, nil
 }
 
+func (c *GrpcClient) notifyDisconnected() {
+	c.connStateCallbackLock.RLock()
+	defer c.connStateCallbackLock.RUnlock()
+
+	if c.connStateCallback == nil {
+		return
+	}
+	c.connStateCallback.MarkManagementDisconnected()
+}
+
+func (c *GrpcClient) notifyConnected() {
+	c.connStateCallbackLock.RLock()
+	defer c.connStateCallbackLock.RUnlock()
+
+	if c.connStateCallback == nil {
+		return
+	}
+	c.connStateCallback.MarkManagementConnected()
+}
+
 func infoToMetaData(info *system.Info) *proto.PeerSystemMeta {
 	if info == nil {
 		return nil