Evaluate dependency group state only for a specific child

Previously the dependency state was evaluated by picking the first
dependency object from the batched members. However, since the
dependency `disable_{checks,notifications` attributes aren't taken into
account when batching the members, the evaluated state may yield a wrong
result for some Checkables due to some random dependency from other
Checkable of that group that has the `disable_{checks,notifications`
attrs set. This commit forces the callers to always provide the child
Checkable the state is evaluated for and picks only the dependency
objects of that child Checkable.

Author: yhabteab

lib/icinga/checkable-dependency.cpp

@@ -204,7 +204,7 @@ bool Checkable::IsReachable(DependencyType dt, int rstack) const
 	}
 
 	for (auto& dependencyGroup : GetDependencyGroups()) {
-		if (auto state(dependencyGroup->GetState(dt, rstack + 1)); !state.Reachable || !state.OK) {
+		if (auto state(dependencyGroup->GetState(this, dt, rstack + 1)); !state.Reachable || !state.OK) {
 			Log(LogDebug, "Checkable")
 				<< "Dependency group '" << dependencyGroup->GetRedundancyGroupName() << "' have failed for checkable '"
 				<< GetName() << "': Marking as unreachable.";

lib/icinga/dependency-group.cpp

@@ -324,9 +324,13 @@ String DependencyGroup::GetCompositeKey()
  * a dependency group may still be marked as failed even when it has reachable parent Checkables, but an unreachable
  * group has always a failed state.
  *
+ * @param child The child Checkable to evaluate the state for.
+ * @param dt The dependency type to evaluate the state for, defaults to DependencyState.
+ * @param rstack The recursion stack level to prevent infinite recursion, defaults to 0.
+ *
  * @return - Returns the state of the current dependency group.
  */
-DependencyGroup::State DependencyGroup::GetState(DependencyType dt, int rstack) const
+DependencyGroup::State DependencyGroup::GetState(const Checkable* child, DependencyType dt, int rstack) const
 {
 	MembersMap members;
 	{
@@ -340,15 +344,27 @@ DependencyGroup::State DependencyGroup::GetState(DependencyType dt, int rstack)
 	for (auto& [_, dependencies] : members) {
 		ASSERT(!dependencies.empty());
 
-		// Dependencies are grouped by parent and all config attributes affecting their availability. Hence, only
-		// one dependency from the map entry has to be considered, all others will share the same state.
-		if (auto& [_, dependency] = *dependencies.begin(); dependency->GetParent()->IsReachable(dt, rstack)) {
-			reachable++;
+		auto [begin, end] = dependencies.equal_range(child);
+		for (auto it(begin); it != end; ++it) {
+			Dependency::Ptr dependency(it->second);
+			if (dependency->GetParent()->IsReachable(dt, rstack)) {
+				reachable++;
+
+				// Only reachable parents are considered for availability. If they are unreachable and checks are disabled,
+				// they could be incorrectly treated as available otherwise.
+				if (dependency->IsAvailable(dt)) {
+					available++;
+				}
+			}
 
-			// Only reachable parents are considered for availability. If they are unreachable and checks are disabled,
-			// they could be incorrectly treated as available otherwise.
-			if (dependency->IsAvailable(dt)) {
-				available++;
+			if (dt == DependencyState) {
+				// Dependencies are grouped by parent and all config attributes affecting their availability.
+				// However, their disable_{checks,notifications} attrs aren't taken into account when grouping them,
+				// thus the map may contain multiple dependencies for that child with different config of these attrs.
+				// Therefore, if this state evaluation is for DependencyState, we can break here as we only need to
+				// consider only a single dependency as they all share the same state, otherwise we need to evaluate
+				// all of them.
+				break;
 			}
 		}
 	}

lib/icinga/dependency.hpp

@@ -163,7 +163,7 @@ class DependencyGroup final : public SharedObject
 		bool OK; // Whether the dependency group is reachable and OK.
 	};
 
-	State GetState(DependencyType dt = DependencyState, int rstack = 0) const;
+	State GetState(const Checkable* child, DependencyType dt = DependencyState, int rstack = 0) const;
 
 	static boost::signals2::signal<void(const Checkable::Ptr&, const DependencyGroup::Ptr&)> OnChildRegistered;
 	static boost::signals2::signal<void(const DependencyGroup::Ptr&, const std::vector<Dependency::Ptr>&)> OnChildRemoved;

lib/icingadb/icingadb-objects.cpp

@@ -1275,7 +1275,7 @@ void IcingaDB::InsertCheckableDependencies(
 					AddObjectDataToRuntimeUpdates(*runtimeUpdates, redundancyGroupId, m_PrefixConfigObject + "dependency:node", nodeData);
 				}
 
-				auto stateAttrs(SerializeRedundancyGroupState(dependencyGroup));
+				auto stateAttrs(SerializeRedundancyGroupState(checkable, dependencyGroup));
 				hmsetRedundancyGroupsStates.emplace_back(redundancyGroupId);
 				hmsetRedundancyGroupsStates.emplace_back(JsonEncode(stateAttrs));
 
@@ -1471,7 +1471,7 @@ void IcingaDB::UpdateDependenciesState(const Checkable::Ptr& checkable) const
 		}
 
 		if (isRedundancyGroup) {
-			Dictionary::Ptr stateAttrs(SerializeRedundancyGroupState(dependencyGroup));
+			Dictionary::Ptr stateAttrs(SerializeRedundancyGroupState(checkable, dependencyGroup));
 
 			Dictionary::Ptr sharedGroupState(stateAttrs->ShallowClone());
 			sharedGroupState->Remove("redundancy_group_id");

lib/icingadb/icingadb-utility.cpp

@@ -202,9 +202,9 @@ Dictionary::Ptr IcingaDB::SerializeDependencyEdgeState(const DependencyGroup::Pt
  *
  * @return A dictionary with the serialized redundancy group state.
  */
-Dictionary::Ptr IcingaDB::SerializeRedundancyGroupState(const DependencyGroup::Ptr& redundancyGroup)
+Dictionary::Ptr IcingaDB::SerializeRedundancyGroupState(const Checkable::Ptr& child, const DependencyGroup::Ptr& redundancyGroup)
 {
-	auto state(redundancyGroup->GetState());
+	auto state(redundancyGroup->GetState(child.get()));
 	return new Dictionary{
 		{"id", redundancyGroup->GetIcingaDBIdentifier()},
 		{"environment_id", m_EnvironmentId},

lib/icingadb/icingadb.hpp

@@ -164,7 +164,7 @@ class IcingaDB : public ObjectImpl<IcingaDB>
 	static const char* GetNotificationTypeByEnum(NotificationType type);
 	static Dictionary::Ptr SerializeVars(const Dictionary::Ptr& vars);
 	static Dictionary::Ptr SerializeDependencyEdgeState(const DependencyGroup::Ptr& dependencyGroup, const Dependency::Ptr& dep);
-	static Dictionary::Ptr SerializeRedundancyGroupState(const DependencyGroup::Ptr& redundancyGroup);
+	static Dictionary::Ptr SerializeRedundancyGroupState(const Checkable::Ptr& child, const DependencyGroup::Ptr& redundancyGroup);
 
 	static String HashValue(const Value& value);
 	static String HashValue(const Value& value, const std::set<String>& propertiesBlacklist, bool propertiesWhitelist = false);