fix(controller): only send status updates when the status changed

internal/controller/reconciler_events_test.go

@@ -192,6 +192,25 @@ func assertNoEventEmitted(t *testing.T, events []string, reason string) {
 	}
 }
 
+// countWDStatusWrites returns interceptor funcs that count status writes issued for a
+// WorkerDeployment, passing each one through to the fake client.
+func countWDStatusWrites(count *int) interceptor.Funcs {
+	return interceptor.Funcs{
+		SubResourceUpdate: func(
+			ctx context.Context,
+			c client.Client,
+			subResourceName string,
+			obj client.Object,
+			opts ...client.SubResourceUpdateOption,
+		) error {
+			if _, ok := obj.(*temporaliov1alpha1.WorkerDeployment); ok && subResourceName == "status" {
+				*count++
+			}
+			return c.SubResource(subResourceName).Update(ctx, obj, opts...)
+		},
+	}
+}
+
 // ─── Stub types ──────────────────────────────────────────────────────────────
 
 // stubWDHandle implements sdkclient.WorkerDeploymentHandle with configurable per-method errors.
@@ -680,6 +699,76 @@ func TestReconcile_DescribeWorkerDeploymentNotFound(t *testing.T) {
 	assertNoEventEmitted(t, drainEvents(recorder), ReasonPlanGenerationFailed)
 }
 
+// TestReconcile_SteadyState_SkipsStatusWrite verifies that once the rollout settles, a
+// reconcile that recomputes the same status does not send it back to the API server.
+func TestReconcile_SteadyState_SkipsStatusWrite(t *testing.T) {
+	ctx := context.Background()
+	k8sNamespace := "default"
+
+	tc := makeNoCredsConnection("my-conn", k8sNamespace, "localhost:7233")
+	twd := makeWD("test-worker", k8sNamespace, tc.Name)
+
+	writes := 0
+	r, _ := newTestReconcilerWithInterceptors([]client.Object{twd, tc}, countWDStatusWrites(&writes))
+	r.TemporalClientPool.SetClientForTesting(
+		noCredsPoolKey(tc.Spec.HostPort, twd.Spec.WorkerOptions.TemporalNamespace),
+		newStubTemporalClient(nil),
+	)
+
+	req := ctrl.Request{NamespacedName: types.NamespacedName{Name: twd.Name, Namespace: twd.Namespace}}
+	// Reconcile enough times to reach steady state (it settles after two reconciles)
+	for i := 0; i < 5; i++ {
+		_, err := r.Reconcile(ctx, req)
+		require.NoError(t, err)
+	}
+
+	// Nothing has changed and there should be no further status updates after a few reconciles.
+	writes = 0
+	for i := 0; i < 5; i++ {
+		_, err := r.Reconcile(ctx, req)
+		require.NoError(t, err)
+	}
+	assert.Zero(t, writes)
+}
+
+// TestReconcile_SpecChange_StillWritesStatus verifies that once the rollout settles, a change that
+// makes the status differ again is still written to the API server.
+func TestReconcile_SpecChange_StillWritesStatus(t *testing.T) {
+	ctx := context.Background()
+	k8sNamespace := "default"
+
+	tc := makeNoCredsConnection("my-conn", k8sNamespace, "localhost:7233")
+	twd := makeWD("test-worker", k8sNamespace, tc.Name)
+
+	writes := 0
+	r, _ := newTestReconcilerWithInterceptors([]client.Object{twd, tc}, countWDStatusWrites(&writes))
+	r.TemporalClientPool.SetClientForTesting(
+		noCredsPoolKey(tc.Spec.HostPort, twd.Spec.WorkerOptions.TemporalNamespace),
+		newStubTemporalClient(nil),
+	)
+
+	req := ctrl.Request{NamespacedName: types.NamespacedName{Name: twd.Name, Namespace: twd.Namespace}}
+	// Reconcile enough times to reach steady state (it settles after two reconciles)
+	for i := 0; i < 5; i++ {
+		_, err := r.Reconcile(ctx, req)
+		require.NoError(t, err)
+	}
+
+	var settled temporaliov1alpha1.WorkerDeployment
+	require.NoError(t, r.Get(ctx, req.NamespacedName, &settled))
+
+	// Trigger a status change by updating the image tag
+	settled.Spec.Template.Spec.Containers[0].Image = "temporal/worker:v2"
+	require.NoError(t, r.Update(ctx, &settled))
+
+	writes = 0
+	_, err := r.Reconcile(ctx, req)
+	require.NoError(t, err)
+
+	// A changed status must have been written, exactly once for the one reconcile
+	assert.Equal(t, 1, writes)
+}
+
 // ─── executeK8sOperations tests ──────────────────────────────────────────────
 
 func TestExecuteK8sOperations_EmitsEventOnFailure(t *testing.T) {

internal/controller/worker_controller.go

@@ -21,6 +21,7 @@ import (
 	grpcstatus "google.golang.org/grpc/status"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/equality"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -139,6 +140,10 @@ func (r *WorkerDeploymentReconciler) Reconcile(ctx context.Context, req ctrl.Req
 		return ctrl.Result{}, r.markWRTsWDNotFound(ctx, req.NamespacedName)
 	}
 
+	// This is the status currently stored in the API server. It is diffed later against the
+	// status computed by this reconcile.
+	observedStatus := workerDeploy.Status.DeepCopy()
+
 	// Migration: if a deprecated TemporalWorkerDeployment with the same name/namespace
 	// exists and has not yet been migrated, transfer ownership of its child Deployments
 	// and WorkerResourceTemplates to this WorkerDeployment.
@@ -386,16 +391,19 @@ func (r *WorkerDeploymentReconciler) Reconcile(ctx context.Context, req ctrl.Req
 	r.syncConditions(&workerDeploy)
 
 	// Single status write per reconcile: persists the generated status and
-	// conditions set during this loop (Ready, Progressing).
-	if err := r.Status().Update(ctx, &workerDeploy); err != nil {
-		if apierrors.IsConflict(err) {
-			return ctrl.Result{
-				Requeue:      true,
-				RequeueAfter: time.Second,
-			}, nil
-		}
-		l.Error(err, "unable to update TemporalWorker status")
-		return ctrl.Result{}, err
+	// conditions set during this loop (Ready, Progressing). Do not send the update
+	// when the status has not changed.
+	if !equality.Semantic.DeepEqual(observedStatus, &workerDeploy.Status) {
+		if err := r.Status().Update(ctx, &workerDeploy); err != nil {
+			if apierrors.IsConflict(err) {
+				return ctrl.Result{
+					Requeue:      true,
+					RequeueAfter: time.Second,
+				}, nil
+			}
+			l.Error(err, "unable to update TemporalWorker status")
+			return ctrl.Result{}, err
+		}
 	}
 
 	return ctrl.Result{