Add readiness retries support for Constraint Templates

Signed-off-by: juliankatz <juliankatz@google.com>

pkg/controller/constrainttemplate/constrainttemplate_controller.go

@@ -324,7 +324,7 @@ func (r *ReconcileConstraintTemplate) Reconcile(ctx context.Context, request rec
 	}
 	unversionedProposedCRD, err := r.opa.CreateCRD(context.Background(), unversionedCT)
 	if err != nil {
-		r.tracker.CancelTemplate(unversionedCT) // Don't track templates that failed compilation
+		r.tracker.TryCancelTemplate(unversionedCT) // Don't track templates that failed compilation
 		r.metrics.registry.add(request.NamespacedName, metrics.ErrorStatus)
 		var createErr *v1beta1.CreateCRDError
 		if parseErrs, ok := err.(ast.Errors); ok {
@@ -347,7 +347,7 @@ func (r *ReconcileConstraintTemplate) Reconcile(ctx context.Context, request rec
 
 	proposedCRD := &apiextensionsv1beta1.CustomResourceDefinition{}
 	if err := r.scheme.Convert(unversionedProposedCRD, proposedCRD, nil); err != nil {
-		r.tracker.CancelTemplate(unversionedCT) // Don't track templates that failed compilation
+		r.tracker.TryCancelTemplate(unversionedCT) // Don't track templates that failed compilation
 		r.metrics.registry.add(request.NamespacedName, metrics.ErrorStatus)
 		log.Error(err, "conversion error")
 		logError(request.NamespacedName.Name)
@@ -419,7 +419,7 @@ func (r *ReconcileConstraintTemplate) handleUpdate(
 			log.Error(err, "failed to report constraint template ingestion duration")
 		}
 		err := r.reportErrorOnCTStatus("ingest_error", "Could not ingest Rego", status, err)
-		r.tracker.CancelTemplate(unversionedCT) // Don't track templates that failed compilation
+		r.tracker.TryCancelTemplate(unversionedCT) // Don't track templates that failed compilation
 		return reconcile.Result{}, err
 	}
 

pkg/readiness/noop_expectations.go

@@ -24,7 +24,9 @@ func (n noopExpectations) Expect(o runtime.Object) {}
 
 func (n noopExpectations) CancelExpect(o runtime.Object) {}
 
-func (n noopExpectations) TryCancelExpect(o runtime.Object) {}
+func (n noopExpectations) TryCancelExpect(o runtime.Object) bool {
+	return false
+}
 
 func (n noopExpectations) ExpectationsDone() {}
 

pkg/readiness/object_tracker.go

@@ -39,7 +39,7 @@ var readinessRetries = flag.Int("readiness-retries", 0, "The number of resource
 type Expectations interface {
 	Expect(o runtime.Object)
 	CancelExpect(o runtime.Object)
-	TryCancelExpect(o runtime.Object)
+	TryCancelExpect(o runtime.Object) bool
 	ExpectationsDone()
 	Observe(o runtime.Object)
 	Satisfied() bool
@@ -146,19 +146,22 @@ func (t *objectTracker) CancelExpect(o runtime.Object) {
 	t.cancelExpectNoLock(k)
 }
 
-func (t *objectTracker) TryCancelExpect(o runtime.Object) {
+// TryCancelExpect will check the readinessRetries left on an Object, and cancel
+// the expectation for that object if no retries remain.  Returns True if the
+// expecatation was cancelled.
+func (t *objectTracker) TryCancelExpect(o runtime.Object) bool {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
 	// Respect circuit-breaker.
 	if t.allSatisfied {
-		return
+		return false
 	}
 
 	k, err := objKeyFromObject(o)
 	if err != nil {
 		log.Error(err, "skipping")
-		return
+		return false
 	}
 
 	// Check if it's time to delete an expectation or just decrement its allotted retries
@@ -173,6 +176,8 @@ func (t *objectTracker) TryCancelExpect(o runtime.Object) {
 	if shouldDel {
 		t.cancelExpectNoLock(k)
 	}
+
+	return shouldDel
 }
 
 // ExpectationsDone tells the tracker to stop accepting new expectations.

pkg/readiness/ready_tracker.go

@@ -131,16 +131,30 @@ func (t *Tracker) ForData(gvk schema.GroupVersionKind) Expectations {
 	return t.data.Get(gvk)
 }
 
-// CancelTemplate stops expecting the provided ConstraintTemplate and associated Constraints.
-func (t *Tracker) CancelTemplate(ct *templates.ConstraintTemplate) {
-	log.V(1).Info("cancel tracking for template", "namespace", ct.GetNamespace(), "name", ct.GetName())
-	t.templates.CancelExpect(ct)
+func (t *Tracker) templateCleanup(ct *templates.ConstraintTemplate) {
 	gvk := constraintGVK(ct)
 	t.constraints.Remove(gvk)
 	<-t.ready // constraintTrackers are setup in Run()
 	t.constraintTrackers.Cancel(gvk.String())
 }
 
+// CancelTemplate stops expecting the provided ConstraintTemplate and associated Constraints.
+func (t *Tracker) CancelTemplate(ct *templates.ConstraintTemplate) {
+	log.V(1).Info("cancel tracking for template", "namespace", ct.GetNamespace(), "name", ct.GetName())
+	t.templates.CancelExpect(ct)
+	t.templateCleanup(ct)
+}
+
+// TryCancelTemplate will check the readiness retries left on a CT and
+// cancel the expectation for that CT and its associated Constraints if
+// no retries remain.
+func (t *Tracker) TryCancelTemplate(ct *templates.ConstraintTemplate) {
+	log.V(1).Info("try to cancel tracking for template", "namespace", ct.GetNamespace(), "name", ct.GetName())
+	if t.templates.TryCancelExpect(ct) {
+		t.templateCleanup(ct)
+	}
+}
+
 // CancelData stops expecting data for the specified resource kind.
 func (t *Tracker) CancelData(gvk schema.GroupVersionKind) {
 	log.V(1).Info("cancel tracking for data", "gvk", gvk)