PBM-1389: warn about sel backup/restore with ConfigShard

Author: defbin

cmd/pbm-agent/agent.go

@@ -118,7 +118,7 @@ func (a *Agent) showIncompatibilityWarning(ctx context.Context) {
 			Warning("", "", "", primitive.Timestamp{}, "WARNING: %v", err)
 	}
 
-	if a.brief.Version.IsShardedTimeseriesSupported() {
+	if a.brief.Sharded && a.brief.Version.IsShardedTimeseriesSupported() {
 		tss, err := topo.ListShardedTimeseries(ctx, a.leadConn)
 		if err != nil {
 			log.FromContext(ctx).
@@ -131,6 +131,19 @@ func (a *Agent) showIncompatibilityWarning(ctx context.Context) {
 					strings.Join(tss, ", "))
 		}
 	}
+
+	if a.brief.Sharded && a.brief.Version.IsConfigShardSupported() {
+		hasConfigShard, err := topo.HasConfigShard(ctx, a.leadConn)
+		if err != nil {
+			log.FromContext(ctx).
+				Error("", "", "", primitive.Timestamp{},
+					"failed to check for Config Shard: %v", err)
+		} else if hasConfigShard {
+			log.FromContext(ctx).
+				Warning("", "", "", primitive.Timestamp{},
+					"WARNING: selective backup and restore is not supported with Config Shard")
+		}
+	}
 }
 
 // Start starts listening the commands stream.

pbm/topo/cluster.go

@@ -171,6 +171,21 @@ func getShardMapImpl(ctx context.Context, m *mongo.Client) (map[ReplsetName]Shar
 	return shards, nil
 }
 
+// HasConfigShard return true if configsvr is listened in shards list
+func HasConfigShard(ctx context.Context, conn connect.Client) (bool, error) {
+	err := conn.MongoClient().Database("config").Collection("shards").
+		FindOne(ctx, bson.D{{"_id", "config"}}).
+		Err()
+	if err == nil {
+		return true, nil // OK: config shard is found
+	}
+	if errors.Is(err, mongo.ErrNoDocuments) {
+		return false, nil // OK: config shard is not found
+	}
+
+	return false, errors.Wrap(err, "query")
+}
+
 type BalancerMode string
 
 const (

pbm/version/version.go

@@ -193,6 +193,10 @@ func (v MongoVersion) IsShardedTimeseriesSupported() bool {
 	return v.Version[0] >= 6 // sharded timeseries introduced in 5.1
 }
 
+func (v MongoVersion) IsConfigShardSupported() bool {
+	return v.Version[0] >= 8
+}
+
 func GetMongoVersion(ctx context.Context, m *mongo.Client) (MongoVersion, error) {
 	res := m.Database("admin").RunCommand(ctx, bson.D{{"buildInfo", 1}})
 	if err := res.Err(); err != nil {