fix(watcher): queues not polling when status updated (#712)

With reference to
#707

This fixes the behaviour of requeues

Co-authored-by: Christoph Bühler <buehler@users.noreply.github.com>

src/KubeOps.Operator/Watcher/ResourceWatcher{TEntity}.cs

@@ -111,7 +111,6 @@ private async void OnEntityRequeue(object? sender, (string Name, string? Namespa
             return;
         }
 
-        _entityCache.TryRemove(entity.Uid(), out _);
         await ReconcileModification(entity);
     }
 
@@ -173,16 +172,32 @@ private async void OnEvent(WatchEventType type, TEntity entity)
             entity.Name(),
             _lastResourceVersion);
 
-        _queue.RemoveIfQueued(entity);
-
         try
         {
             switch (type)
             {
-                case WatchEventType.Added or WatchEventType.Modified:
+                case WatchEventType.Added:
+                    _entityCache.TryAdd(entity.Uid(), entity.Generation() ?? 0);
+                    await ReconcileModification(entity);
+                    break;
+                case WatchEventType.Modified:
                     switch (entity)
                     {
                         case { Metadata.DeletionTimestamp: null }:
+                            _entityCache.TryGetValue(entity.Uid(), out var cachedGeneration);
+
+                            // Check if entity spec has changed through "Generation" value increment. Skip reconcile if not changed.
+                            if (entity.Generation() <= cachedGeneration)
+                            {
+                                _logger.LogDebug(
+                                    """Entity "{kind}/{name}" modification did not modify generation. Skip event.""",
+                                    entity.Kind,
+                                    entity.Name());
+                                return;
+                            }
+
+                            // update cached generation since generation now changed
+                            _entityCache.TryUpdate(entity.Uid(), entity.Generation() ?? 1, cachedGeneration);
                             await ReconcileModification(entity);
                             break;
                         case { Metadata: { DeletionTimestamp: not null, Finalizers.Count: > 0 } }:
@@ -216,31 +231,25 @@ private async void OnEvent(WatchEventType type, TEntity entity)
 
     private async Task ReconcileModification(TEntity entity)
     {
-        var latestGeneration = _entityCache.GetOrAdd(entity.Uid(), 0);
-        if (entity.Generation() <= latestGeneration)
-        {
-            _logger.LogDebug(
-                """Entity "{kind}/{name}" modification did not modify generation. Skip event.""",
-                entity.Kind,
-                entity.Name());
-            return;
-        }
-
-        _entityCache.TryUpdate(entity.Uid(), entity.Generation() ?? 1, latestGeneration);
+        // Re-queue should requested in the controller reconcile method. Invalidate any existing queues.
+        _queue.RemoveIfQueued(entity);
         await using var scope = _provider.CreateAsyncScope();
         var controller = scope.ServiceProvider.GetRequiredService<IEntityController<TEntity>>();
         await controller.ReconcileAsync(entity);
     }
 
     private async Task ReconcileDeletion(TEntity entity)
     {
+        _queue.RemoveIfQueued(entity);
+        _entityCache.TryRemove(entity.Uid(), out _);
         await using var scope = _provider.CreateAsyncScope();
         var controller = scope.ServiceProvider.GetRequiredService<IEntityController<TEntity>>();
         await controller.DeletedAsync(entity);
     }
 
     private async Task ReconcileFinalizer(TEntity entity)
     {
+        _queue.RemoveIfQueued(entity);
         var pendingFinalizer = entity.Finalizers();
         if (_finalizers.Value.Find(reg =>
                 reg.EntityType == entity.GetType() && pendingFinalizer.Contains(reg.Identifier)) is not

test/KubeOps.Operator.Test/Controller/CancelEntityRequeue.Integration.Test.cs

@@ -34,6 +34,20 @@ public async Task Should_Cancel_Requeue_If_New_Event_Fires()
         Services.GetRequiredService<TimedEntityQueue<V1OperatorIntegrationTestEntity>>().Count.Should().Be(0);
     }
 
+    [Fact]
+    public async Task Should_Not_Affect_Queues_If_Only_Status_Updated()
+    {
+        _mock.TargetInvocationCount = 1;
+        var result = await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity", "username", _ns.Namespace));
+        result.Status.Status = "changed";
+        await _client.UpdateStatusAsync(result);
+        await _mock.WaitForInvocations;
+
+        _mock.Invocations.Count.Should().Be(1);
+        Services.GetRequiredService<TimedEntityQueue<V1OperatorIntegrationTestEntity>>().Count.Should().Be(1);
+
+    }
+
     public override async Task InitializeAsync()
     {
         await base.InitializeAsync();

test/KubeOps.Operator.Test/Controller/EntityController.Integration.Test.cs

@@ -57,6 +57,27 @@ void Check(int idx, string username)
         }
     }
 
+    [Fact]
+    public async Task Should_Not_Call_Reconcile_When_Only_Entity_Status_Changed()
+    {
+        _mock.TargetInvocationCount = 1;
+
+        var result =
+            await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity", "username", _ns.Namespace));
+        result.Status.Status = "changed";
+        // Update or UpdateStatus do not call Reconcile
+        await _client.UpdateAsync(result);
+        await _client.UpdateStatusAsync(result);
+        await _mock.WaitForInvocations;
+
+        _mock.Invocations.Count.Should().Be(1);
+
+        (string method, V1OperatorIntegrationTestEntity entity) = _mock.Invocations.Single();
+        method.Should().Be("ReconcileAsync");
+        entity.Should().BeOfType<V1OperatorIntegrationTestEntity>();
+        entity.Spec.Username.Should().Be("username");
+    }
+
     [Fact]
     public async Task Should_Call_Delete_For_Deleted_Entity()
     {

test/KubeOps.Operator.Test/Controller/EntityRequeue.Integration.Test.cs

@@ -35,6 +35,30 @@ public async Task Should_Requeue_Entity_And_Reconcile()
         _mock.Invocations.Count.Should().Be(5);
     }
 
+    [Fact]
+    public async Task Should_Separately_And_Reliably_Requeue_And_Reconcile_Multiple_Entities_In_Parallel()
+    {
+        _mock.TargetInvocationCount = 100;
+        await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity1", "username", _ns.Namespace));
+        await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity2", "username", _ns.Namespace));
+        await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity3", "username", _ns.Namespace));
+        await _client.CreateAsync(new V1OperatorIntegrationTestEntity("test-entity4", "username", _ns.Namespace));
+        await _mock.WaitForInvocations;
+
+        // Expecting invocations, but since in parallel, there is a possibility to for target hit while other are in flight.
+        _mock.Invocations.Count.Should().BeGreaterOrEqualTo(100).And.BeLessThan(105);
+        var invocationsGroupedById = _mock.Invocations.GroupBy(item => item.Entity.Metadata.Uid).ToList();
+        invocationsGroupedById.Count.Should().Be(4);
+        var invocationDistributions = invocationsGroupedById
+            .Select(g => (double)g.Count() / _mock.Invocations.Count * 100)
+            .ToList();
+        invocationDistributions
+            .All(p => p is >= 15 and <= 35) // Check that invocations are reasonably distributed
+            .Should()
+            .BeTrue($"each entity invocation proportion should be within the specified range of total invocations, " +
+                    $"but instead the distributions were: '{string.Join(", ", invocationDistributions)}'");
+    }
+
     public override async Task InitializeAsync()
     {
         await base.InitializeAsync();