Fix panic due to missing memcachedInstance

We currently assign to the subCR spec memcached instance under certain
conditions. We observe a panic for the subcontrollers (api/scheduler/shares)
on [1] when it tries to dereference a field that is a nil pointer, and
this let the operator crash without any chance to recover.
If you try to patch the manilaShare backend you can easily see that.
Regardless of the memcached CR config (TLS or not), we always wait in
the main controller for it to be ready, and only then we unblock the
rest of the reconciliation loop.
For this reason, we can always assign to the underlying components
the MemcachedInstance defined at the top-level because:
1. we know it exists
2. we need to pass it down to the statefulset and we do not support
   a different memcached instance per component (we only support
   inheritance from the top-level)

Based on the above, the subCR parameter is not independent, and needs
to always be assigned from the top-level controller.
The statefulSet produces the right configuration according to the
memcached instance retrieved from the namespace.
This patch fixes the panic by always assigning the MemcachedInstance
to the subCR template.

Signed-off-by: Francesco Pantano <fpantano@redhat.com>

Author: fmount

controllers/manila_controller.go

@@ -728,7 +728,7 @@ func (r *ManilaReconciler) reconcileNormal(ctx context.Context, instance *manila
 	//
 
 	// deploy manila-api
-	manilaAPI, op, err := r.apiDeploymentCreateOrUpdate(ctx, instance, memcached)
+	manilaAPI, op, err := r.apiDeploymentCreateOrUpdate(ctx, instance)
 	if err != nil {
 		instance.Status.Conditions.Set(condition.FalseCondition(
 			manilav1beta1.ManilaAPIReadyCondition,
@@ -776,7 +776,7 @@ func (r *ManilaReconciler) reconcileNormal(ctx context.Context, instance *manila
 	}
 
 	// Deploy ManilaScheduler
-	manilaScheduler, op, err := r.schedulerDeploymentCreateOrUpdate(ctx, instance, memcached)
+	manilaScheduler, op, err := r.schedulerDeploymentCreateOrUpdate(ctx, instance)
 	if err != nil {
 		instance.Status.Conditions.Set(condition.FalseCondition(
 			manilav1beta1.ManilaSchedulerReadyCondition,
@@ -819,7 +819,7 @@ func (r *ManilaReconciler) reconcileNormal(ctx context.Context, instance *manila
 	// Deploy ManilaShare
 	var shareCondition *condition.Condition
 	for name, share := range instance.Spec.ManilaShares {
-		manilaShare, op, err := r.shareDeploymentCreateOrUpdate(ctx, instance, name, share, serviceLabels, memcached)
+		manilaShare, op, err := r.shareDeploymentCreateOrUpdate(ctx, instance, name, share, serviceLabels)
 		if err != nil {
 			instance.Status.Conditions.Set(condition.FalseCondition(
 				manilav1beta1.ManilaShareReadyCondition,
@@ -1094,7 +1094,7 @@ func (r *ManilaReconciler) createHashOfInputHashes(
 	return hash, changed, nil
 }
 
-func (r *ManilaReconciler) apiDeploymentCreateOrUpdate(ctx context.Context, instance *manilav1beta1.Manila, memcached *memcachedv1.Memcached) (*manilav1beta1.ManilaAPI, controllerutil.OperationResult, error) {
+func (r *ManilaReconciler) apiDeploymentCreateOrUpdate(ctx context.Context, instance *manilav1beta1.Manila) (*manilav1beta1.ManilaAPI, controllerutil.OperationResult, error) {
 	deployment := &manilav1beta1.ManilaAPI{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      fmt.Sprintf("%s-api", instance.Name),
@@ -1109,6 +1109,7 @@ func (r *ManilaReconciler) apiDeploymentCreateOrUpdate(ctx context.Context, inst
 		DatabaseHostname:   instance.Status.DatabaseHostname,
 		TransportURLSecret: instance.Status.TransportURLSecret,
 		ServiceAccount:     instance.RbacResourceName(),
+		MemcachedInstance:  &instance.Spec.MemcachedInstance,
 	}
 
 	if apiSpec.NodeSelector == nil {
@@ -1121,12 +1122,6 @@ func (r *ManilaReconciler) apiDeploymentCreateOrUpdate(ctx context.Context, inst
 		apiSpec.TopologyRef = instance.Spec.TopologyRef
 	}
 
-	// If memcached is not present in the underlying ManilaAPI Spec,
-	// inherit from the top-level CR (only when MTLS is in use)
-	if memcached.GetMemcachedMTLSSecret() != "" {
-		apiSpec.MemcachedInstance = &instance.Spec.MemcachedInstance
-	}
-
 	op, err := controllerutil.CreateOrUpdate(ctx, r.Client, deployment, func() error {
 		deployment.Spec = apiSpec
 
@@ -1145,7 +1140,7 @@ func (r *ManilaReconciler) apiDeploymentCreateOrUpdate(ctx context.Context, inst
 	return deployment, op, err
 }
 
-func (r *ManilaReconciler) schedulerDeploymentCreateOrUpdate(ctx context.Context, instance *manilav1beta1.Manila, memcached *memcachedv1.Memcached) (*manilav1beta1.ManilaScheduler, controllerutil.OperationResult, error) {
+func (r *ManilaReconciler) schedulerDeploymentCreateOrUpdate(ctx context.Context, instance *manilav1beta1.Manila) (*manilav1beta1.ManilaScheduler, controllerutil.OperationResult, error) {
 	deployment := &manilav1beta1.ManilaScheduler{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      fmt.Sprintf("%s-scheduler", instance.Name),
@@ -1161,6 +1156,7 @@ func (r *ManilaReconciler) schedulerDeploymentCreateOrUpdate(ctx context.Context
 		TransportURLSecret:      instance.Status.TransportURLSecret,
 		ServiceAccount:          instance.RbacResourceName(),
 		TLS:                     instance.Spec.ManilaAPI.TLS.Ca,
+		MemcachedInstance:       &instance.Spec.MemcachedInstance,
 	}
 
 	if schedulerSpec.NodeSelector == nil {
@@ -1173,12 +1169,6 @@ func (r *ManilaReconciler) schedulerDeploymentCreateOrUpdate(ctx context.Context
 		schedulerSpec.TopologyRef = instance.Spec.TopologyRef
 	}
 
-	// If memcached is not present in the underlying ManilaScheduler Spec,
-	// inherit from the top-level CR (only when MTLS is in use)
-	if memcached.GetMemcachedMTLSSecret() != "" {
-		schedulerSpec.MemcachedInstance = &instance.Spec.MemcachedInstance
-	}
-
 	op, err := controllerutil.CreateOrUpdate(ctx, r.Client, deployment, func() error {
 		deployment.Spec = schedulerSpec
 
@@ -1203,7 +1193,6 @@ func (r *ManilaReconciler) shareDeploymentCreateOrUpdate(
 	name string,
 	share manilav1beta1.ManilaShareTemplate,
 	serviceLabels map[string]string,
-	memcached *memcachedv1.Memcached,
 ) (*manilav1beta1.ManilaShare, controllerutil.OperationResult, error) {
 
 	// Add the ShareName to the ManilaShare instance as a label
@@ -1224,6 +1213,7 @@ func (r *ManilaReconciler) shareDeploymentCreateOrUpdate(
 		TransportURLSecret:  instance.Status.TransportURLSecret,
 		ServiceAccount:      instance.RbacResourceName(),
 		TLS:                 instance.Spec.ManilaAPI.TLS.Ca,
+		MemcachedInstance:   &instance.Spec.MemcachedInstance,
 	}
 
 	if shareSpec.NodeSelector == nil {
@@ -1236,12 +1226,6 @@ func (r *ManilaReconciler) shareDeploymentCreateOrUpdate(
 		shareSpec.TopologyRef = instance.Spec.TopologyRef
 	}
 
-	// If memcached is not present in the underlying ManilaSchare Spec,
-	// inherit from the top-level CR (only when MTLS is in use)
-	if memcached.GetMemcachedMTLSSecret() != "" {
-		shareSpec.MemcachedInstance = &instance.Spec.MemcachedInstance
-	}
-
 	op, err := controllerutil.CreateOrUpdate(ctx, r.Client, deployment, func() error {
 		deployment.Spec = shareSpec