add no-rack no-dc flags to nodes response (#6004)

Author: adameat

ydb/core/viewer/json_nodes.h

@@ -749,6 +749,9 @@ class TJsonNodes : public TViewerPipeClient<TJsonNodes> {
             }
         }
 
+        bool noDC = true;
+        bool noRack = true;
+
         for (TNodeId nodeId : NodeIds) {
             if (!CheckNodeFilters(nodeId)) {
                 continue;
@@ -799,6 +802,19 @@ class TJsonNodes : public TViewerPipeClient<TJsonNodes> {
                     }
                 }
             }
+
+            if (!nodeInfo.GetSystemState().GetLocation().GetDataCenter().empty()) {
+                noDC = false;
+            }
+            if (nodeInfo.GetSystemState().GetSystemLocation().GetDataCenter() != 0) {
+                noDC = false;
+            }
+            if (!nodeInfo.GetSystemState().GetLocation().GetRack().empty()) {
+                noRack = false;
+            }
+            if (nodeInfo.GetSystemState().GetSystemLocation().GetRack() != 0) {
+                noRack = false;
+            }
         }
 
         if (!SortedNodeList) {
@@ -883,6 +899,12 @@ class TJsonNodes : public TViewerPipeClient<TJsonNodes> {
         if (MaximumDisksPerNode.has_value()) {
             result.SetMaximumDisksPerNode(MaximumDisksPerNode.value());
         }
+        if (noDC) {
+            result.SetNoDC(true);
+        }
+        if (noRack) {
+            result.SetNoRack(true);
+        }
 
         TStringStream json;
         TProtoToJson::ProtoToJson(json, result, JsonSettings);

ydb/core/viewer/protos/viewer.proto

@@ -439,6 +439,8 @@ message TNodesInfo {
     optional uint64 TotalNodes = 3;
     optional uint64 FoundNodes = 4;
     optional uint64 MaximumDisksPerNode = 5;
+    optional bool NoDC = 6;
+    optional bool NoRack = 7;
 }
 
 enum ENodeType {