pass sync message version in SyncResponse

Signed-off-by: Dmitri Dolguikh <dmitri.external@netbird.io>

client/internal/engine.go

@@ -995,12 +995,17 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 		nm         *mgmProto.NetworkMap
 		components *types.NetworkMapComponents
 	)
-	if envelope := update.GetNetworkMapEnvelope(); envelope != nil {
+	if version := update.GetVersion(); version == mgmProto.SyncResponseVersion_VersionComponentNetworkMap {
 		// Components-format peer: decode the envelope back to typed
 		// components, run Calculate() locally, and convert to the wire
 		// NetworkMap shape the rest of the engine consumes. Components are
 		// retained so future incremental updates can apply deltas instead
 		// of doing a full reconstruction.
+		envelope := update.GetNetworkMapEnvelope()
+		if envelope == nil {
+			return fmt.Errorf("received a SyncReponse indicating use of components network map, but components are missing")
+		}
+
 		localKey := e.config.WgPrivateKey.PublicKey().String()
 		dnsName := ""
 		if pc := update.GetPeerConfig(); pc != nil {

management/internals/shared/grpc/components_envelope_response.go

@@ -72,6 +72,7 @@ func ToComponentSyncResponse(
 		PeerConfig:         peerConfig,
 		NetworkMapEnvelope: envelope,
 		Checks:             toProtocolChecks(ctx, checks),
+		Version:            proto.SyncResponseVersion_VersionComponentNetworkMap,
 	}
 
 	nbConfig := toNetbirdConfig(config, turnCredentials, relayCredentials, extraSettings, settings)

shared/management/networkmap/decode.go

@@ -28,9 +28,6 @@ import (
 //
 //	Peers              base64(wg_pub_key)          // stable across snapshots
 func DecodeEnvelope(env *proto.NetworkMapEnvelope) (*types.NetworkMapComponents, error) {
-	if env == nil {
-		return nil, fmt.Errorf("nil envelope")
-	}
 	full := env.GetFull()
 	if full == nil {
 		return nil, fmt.Errorf("envelope has no Full payload")

shared/management/proto/management.proto

@@ -121,6 +121,11 @@ message SyncRequest {
   PeerSystemMeta meta = 1;
 }
 
+enum SyncResponseVersion {
+  VersionUnknown = 0;
+  VersionComponentNetworkMap = 1;
+}
+
 // SyncResponse represents a state that should be applied to the local peer (e.g. Netbird servers config as well as local peer and remote peers configs)
 message SyncResponse {
 
@@ -156,6 +161,8 @@ message SyncResponse {
   // is left empty: management ships components and the client runs Calculate()
   // locally instead of receiving an expanded NetworkMap.
   NetworkMapEnvelope NetworkMapEnvelope = 8;
+
+  SyncResponseVersion Version = 9;
 }
 
 message  SyncMetaRequest {