MaintenanceManager: Implement helpers to remove non existent nodes fr…

…om maintenance and to check if a maintenance is empty

Summary:
Two new helper functions to:
1- Given a maintenance, remove all the non existent shards/sequencers out of it.
2- Given a maintenance, checks whether the maintenance is empty or not (usually used after #1).

Reviewed By: AhmedSoliman

Differential Revision: D17684399

fbshipit-source-id: 27eb1324eddb4f214f2ac86303edd1367682cac2

logdevice/admin/maintenance/APIUtils.cpp

@@ -370,5 +370,32 @@ bool doesMaintenanceMatchFilter(const thrift::MaintenancesFilter& filter,
   return true;
 }
 
+void removeNonExistentNodesFromMaintenance(
+    thrift::MaintenanceDefinition& maintenance,
+    const configuration::nodes::NodesConfiguration& nodes_configuration) {
+  maintenance.shards.erase(
+      std::remove_if(maintenance.shards.begin(),
+                     maintenance.shards.end(),
+                     [&](const auto& shard) {
+                       return !findNodeIndex(
+                                   shard.get_node(), nodes_configuration)
+                                   .hasValue();
+                     }),
+      maintenance.shards.end());
+  maintenance.sequencer_nodes.erase(
+      std::remove_if(
+          maintenance.sequencer_nodes.begin(),
+          maintenance.sequencer_nodes.end(),
+          [&](const auto& node) {
+            return !findNodeIndex(node, nodes_configuration).hasValue();
+          }),
+      maintenance.sequencer_nodes.end());
+}
+
+bool isEmptyMaintenance(const thrift::MaintenanceDefinition& maintenance) {
+  return maintenance.get_shards().empty() &&
+      maintenance.get_sequencer_nodes().empty();
+}
+
 } // namespace APIUtils
 }}} // namespace facebook::logdevice::maintenance

logdevice/admin/maintenance/APIUtils.h

@@ -118,5 +118,18 @@ void matchMaintenances(const thrift::MaintenancesFilter& filter,
 bool doesMaintenanceMatchFilter(const thrift::MaintenancesFilter& filter,
                                 const MaintenanceDefinition& def);
 
+/**
+ * Filters out shards/sequencers from maintenance definition that don't exist in
+ * the nodes configuration anymore.
+ */
+void removeNonExistentNodesFromMaintenance(
+    thrift::MaintenanceDefinition& maintenance,
+    const configuration::nodes::NodesConfiguration& nodes_configuration);
+
+/**
+ * Returns true if the maintenance doesn't have any shards/sequencers to act on.
+ */
+bool isEmptyMaintenance(const thrift::MaintenanceDefinition& maintenance);
+
 } // namespace APIUtils
 }}} // namespace facebook::logdevice::maintenance

logdevice/admin/maintenance/test/APIUtilsTest.cpp

@@ -389,3 +389,53 @@ TEST(APIUtilsTest, MaintenanceFilter) {
   ASSERT_EQ(1, res1.size());
   ASSERT_THAT(res1, UnorderedElementsAre(def1));
 }
+
+TEST(APIUtilsTest, TestIsEmptyMaintenance) {
+  MaintenanceDefinition def;
+  def.set_user("bunny");
+  def.set_shard_target_state(ShardOperationalState::DRAINED);
+  def.set_shards({mkShardID(1, -1), mkShardID(13, -1)});
+  def.set_sequencer_nodes({mkNodeID(1)});
+  def.set_sequencer_target_state(SequencingState::DISABLED);
+  EXPECT_FALSE(APIUtils::isEmptyMaintenance(def));
+
+  def.set_shards({});
+  def.set_sequencer_nodes({mkNodeID(1)});
+  EXPECT_FALSE(APIUtils::isEmptyMaintenance(def));
+
+  def.set_shards({mkShardID(1, -1), mkShardID(13, -1)});
+  def.set_sequencer_nodes({});
+  EXPECT_FALSE(APIUtils::isEmptyMaintenance(def));
+
+  def.set_shards({});
+  def.set_sequencer_nodes({});
+  EXPECT_TRUE(APIUtils::isEmptyMaintenance(def));
+}
+
+TEST(APIUtilsTest, TestRemoveNonExistentNodesFromMaintenance) {
+  MaintenanceDefinition def;
+  def.set_user("bunny");
+  def.set_shard_target_state(ShardOperationalState::DRAINED);
+  def.set_shards(
+      {mkShardID(1, -1), mkShardID(130, 0), mkShardID(0, 1), mkShardID(7, 1)});
+  def.set_sequencer_nodes(
+      {mkNodeID(1), mkNodeID(100), mkNodeID(0), mkNodeID(101)});
+  def.set_sequencer_target_state(SequencingState::DISABLED);
+
+  APIUtils::removeNonExistentNodesFromMaintenance(
+      def, *genNodesConfiguration());
+
+  for (auto seq : def.get_sequencer_nodes()) {
+    LOG(INFO) << *seq.get_node_index();
+  }
+
+  EXPECT_THAT(def.get_shards(),
+              UnorderedElementsAre(mkShardID(1, -1), mkShardID(7, 1)));
+  EXPECT_THAT(def.get_sequencer_nodes(), UnorderedElementsAre(mkNodeID(1)));
+
+  // Trying to remove the nodes again, wouldn't change anything
+  auto def_copy = def;
+  APIUtils::removeNonExistentNodesFromMaintenance(
+      def_copy, *genNodesConfiguration());
+  EXPECT_EQ(def, def_copy);
+}