issue-757: pass path as empty TMaybe<TString> instead of empty TStrin…

…g when registering node in Node Broker; spoil BS Controller config before restarting Kikimr after formatting static pdisks in local-emergency test (otherwise BS Controller would erase all the data from other non-static groups) (#2049)

cloud/blockstore/libs/daemon/ydb/bootstrap.cpp

@@ -232,10 +232,11 @@ void TBootstrapYdb::InitKikimrService()
     };
 
     bool loadCmsConfigs = Configs->Options->LoadCmsConfigs;
-    if (loadCmsConfigs &&
-        (Configs->StorageConfig->GetHiveProxyFallbackMode() ||
-        Configs->StorageConfig->GetSSProxyFallbackMode()))
-    {
+    bool emergencyMode =
+        Configs->StorageConfig->GetHiveProxyFallbackMode() ||
+        Configs->StorageConfig->GetSSProxyFallbackMode();
+
+    if (loadCmsConfigs && emergencyMode) {
         STORAGE_INFO("Disable loading configs from CMS in emergency mode");
         loadCmsConfigs = false;
     }
@@ -251,6 +252,10 @@ void TBootstrapYdb::InitKikimrService()
         .Settings = std::move(settings)
     };
 
+    if (emergencyMode) {
+        registerOpts.SchemeShardDir = "";
+    }
+
     if (Configs->Options->LocationFile) {
         NProto::TLocation location;
         ParseProtoTextFromFile(Configs->Options->LocationFile, location);

cloud/blockstore/tests/loadtest/local-emergency/test.py

@@ -1,4 +1,3 @@
-# import os
 import pytest
 
 import yatest.common as common
@@ -82,15 +81,10 @@ def __run_test(test_case):
     client.execute_action(action="BackupPathDescriptions", input_bytes=str.encode(""))
     client.execute_action(action="BackupTabletBootInfos", input_bytes=str.encode(""))
 
-    static_pdisk_paths = []
-    for info in env.pdisks_info:
-        if info["pdisk_user_kind"] == 0:
-            static_pdisk_paths += [info["pdisk_path"]]
-    assert len(static_pdisk_paths) == 1
-
-    # Destroy static group in order to emulate emergency.
-    # TODO: survive outage of kikimr static tablets.
-    # os.remove(static_pdisk_paths[0])
+    env.kikimr_cluster.format_static_pdisks()
+    # spoil config to prevent BS Controller from starting otherwise it will
+    # erase dynamic groups data
+    env.kikimr_cluster.spoil_bs_controller_config()
     env.kikimr_cluster.restart_nodes()
 
     env.nbs.storage_config_patches = [storage_config_with_emergency_mode(backups_folder)]

cloud/storage/core/libs/kikimr/node.cpp

@@ -224,6 +224,11 @@ struct TLegacyNodeRegistrant
     {
         NClient::TKikimr kikimr(CreateKikimrConfig(Options, nodeBrokerAddress));
 
+        TMaybe<TString> path;
+        if (Options.SchemeShardDir) {
+            path = Options.SchemeShardDir;
+        }
+
         auto registrant = kikimr.GetNodeRegistrant();
         auto result = registrant.SyncRegisterNode(
             Options.Domain,
@@ -232,8 +237,8 @@ struct TLegacyNodeRegistrant
             HostAddress,
             HostName,
             Location,
-            false, //request fixed node id
-            Options.SchemeShardDir);
+            false, // fixedNodeId
+            path);
 
         if (!result.IsSuccess()) {
             return MakeError(

ydb/tests/library/harness/kikimr_runner.py

@@ -494,6 +494,30 @@ def __instantiate_udfs_dir(self):
             os.symlink(udf_path, link_name)
         return self.__common_udfs_dir
 
+    # TODO(svartmetal): remove this when YDB learns not to erase dynamic groups
+    # data after formatting of static pdisks
+    def spoil_bs_controller_config(self):
+        flat_bs_controller = [{
+            "info": {
+                "channels": [{
+                    "channel": 0,
+                    "channel_erasure_name": str(self.__configurator.static_erasure),
+                    "history": [{
+                        "from_generation": 0,
+                        "group_id": 100500
+                    }]
+                }]
+            }
+        }]
+        self.__configurator.yaml_config["system_tablets"]["flat_bs_controller"] = flat_bs_controller
+        self.__write_configs()
+
+    def format_static_pdisks(self):
+        for node_id in self.__configurator.all_node_ids():
+            for pdisk in self.__configurator.pdisks_info:
+                if pdisk["pdisk_user_kind"] == 0:
+                    self.nodes[node_id].format_pdisk(**pdisk)
+
     def __format_disks(self, node_id):
         for pdisk in self.__configurator.pdisks_info:
             if pdisk['node_id'] != node_id: