Draft: do observables as interface

internal/controller/etcdcluster_controller.go

@@ -74,10 +74,13 @@
 
 // Reconcile checks CR and current cluster state and performs actions to transform current state to desired.
 func (r *EtcdClusterReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	var state State
 	log.Debug(ctx, "reconciling object")
-	state := &observables{}
-	state.instance = &etcdaenixiov1alpha1.EtcdCluster{}
-	err := r.Get(ctx, req.NamespacedName, state.instance)
+
+	// TODO: marry abstract interface with actual object pointer
+	// state := &observables{}
+	// state.instance = &etcdaenixiov1alpha1.EtcdCluster{}
+	err := state.GetEtcdCluster()
 	if err != nil {
 		if errors.IsNotFound(err) {
 			log.Debug(ctx, "object not found")
@@ -86,9 +89,10 @@
 		// Error retrieving object, requeue
 		return reconcile.Result{}, err
 	}
-	// If object is being deleted, skipping reconciliation
-	if !state.instance.DeletionTimestamp.IsZero() {
-		return reconcile.Result{}, nil
+
+	// If object is being deleted, handle finalizers, dependent objects, etc
+	if state.PendingDeletion() {
+		return ctrl.Result{}, r.handleDeletion(ctx, state)
 	}
 
 	// create two services and the pdb
@@ -98,14 +102,14 @@
 	}
 
 	// fetch STS if exists
 	err = r.Get(ctx, req.NamespacedName, &state.statefulSet)
 	if client.IgnoreNotFound(err) != nil {
 		return ctrl.Result{}, fmt.Errorf("couldn't get statefulset: %w", err)
 	}
 	// state.stsExists = state.statefulSet.UID != ""
 
 	// fetch endpoints
 	clusterClient, singleClients, err := factory.NewEtcdClientSet(ctx, state.instance, r.Client)
 	if err != nil {
 		return ctrl.Result{}, err
 	}
@@ -114,23 +118,23 @@
 	// if clusterClient != nil {
 	// 	state.endpoints = clusterClient.Endpoints()
 	// }
 	state.clusterClient = clusterClient
 	state.singleClients = singleClients
 
 	// fetch PVCs
 	state.pvcs, err = factory.PVCs(ctx, state.instance, r.Client)
 	if err != nil {
 		return ctrl.Result{}, err
 	}
 
 	if !state.endpointsFound() {
 		if !state.statefulSetExists() {
 			return r.createClusterFromScratch(ctx, state) // TODO: needs implementing
 		}
 
 		// update sts pod template (and only pod template) if it doesn't match desired state
 		if !state.statefulSetPodSpecCorrect() { // TODO: needs implementing
 			desiredSts := factory.TemplateStatefulSet(state.instance) // TODO: needs implementing
 			state.statefulSet.Spec.Template.Spec = desiredSts.Spec.Template.Spec
 			return ctrl.Result{}, r.patchOrCreateObject(ctx, &state.statefulSet)
 		}
@@ -232,7 +236,7 @@
 }
 
 // checkAndDeleteStatefulSetIfNecessary deletes the StatefulSet if the specified storage size has changed.
-func (r *EtcdClusterReconciler) checkAndDeleteStatefulSetIfNecessary(ctx context.Context, state *observables) error {
+func (r *EtcdClusterReconciler) checkAndDeleteStatefulSetIfNecessary(ctx context.Context, state State) error {
 	for _, volumeClaimTemplate := range state.statefulSet.Spec.VolumeClaimTemplates {
 		if volumeClaimTemplate.Name != "data" {
 			continue
@@ -254,7 +258,7 @@
 }
 
 // ensureConditionalClusterObjects creates or updates all objects owned by cluster CR
-func (r *EtcdClusterReconciler) ensureConditionalClusterObjects(ctx context.Context, state *observables) error {
+func (r *EtcdClusterReconciler) ensureConditionalClusterObjects(ctx context.Context, state State) error {
 
 	if err := factory.CreateOrUpdateClusterStateConfigMap(ctx, state.instance, r.Client); err != nil {
 		log.Error(ctx, err, "reconcile cluster state configmap failed")
@@ -277,7 +281,7 @@
 }
 
 // updateStatusOnErr wraps error and updates EtcdCluster status
-func (r *EtcdClusterReconciler) updateStatusOnErr(ctx context.Context, state *observables, err error) (ctrl.Result, error) {
+func (r *EtcdClusterReconciler) updateStatusOnErr(ctx context.Context, state State, err error) (ctrl.Result, error) {
 	// The function 'updateStatusOnErr' will always return non-nil error. Hence, the ctrl.Result will always be ignored.
 	// Therefore, the ctrl.Result returned by 'updateStatus' function can be discarded.
 	// REF: https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/reconcile@v0.17.3#Reconciler
@@ -289,7 +293,7 @@
 }
 
 // updateStatus updates EtcdCluster status and returns error and requeue in case status could not be updated due to conflict
-func (r *EtcdClusterReconciler) updateStatus(ctx context.Context, state *observables) (ctrl.Result, error) {
+func (r *EtcdClusterReconciler) updateStatus(ctx context.Context, state State) (ctrl.Result, error) {
 	err := r.Status().Update(ctx, state.instance)
 	if err == nil {
 		return ctrl.Result{}, nil
@@ -303,7 +307,7 @@
 }
 
 // isStatefulSetReady gets managed StatefulSet and checks its readiness.
-func (r *EtcdClusterReconciler) isStatefulSetReady(ctx context.Context, state *observables) (bool, error) {
+func (r *EtcdClusterReconciler) isStatefulSetReady(ctx context.Context, state State) (bool, error) {
 	sts := &appsv1.StatefulSet{}
 	err := r.Get(ctx, client.ObjectKeyFromObject(state.instance), sts)
 	if err == nil {
@@ -323,7 +327,7 @@
 		Complete(r)
 }
 
-func (r *EtcdClusterReconciler) configureAuth(ctx context.Context, state *observables) error {
+func (r *EtcdClusterReconciler) configureAuth(ctx context.Context, state State) error {
 
 	var err error
 
@@ -603,7 +607,7 @@
 // ensureUnconditionalObjects creates the two services and the PDB
 // which can be created at the start of the reconciliation loop
 // without any risk of disrupting the etcd cluster
-func (r *EtcdClusterReconciler) ensureUnconditionalObjects(ctx context.Context, state *observables) error {
+func (r *EtcdClusterReconciler) ensureUnconditionalObjects(ctx context.Context, state State) error {
 	const concurrentOperations = 3
 	c := make(chan error)
 	defer close(c)
@@ -669,7 +673,7 @@
 
 // TODO!
 // nolint:unparam,unused
-func (r *EtcdClusterReconciler) createClusterFromScratch(ctx context.Context, state *observables) (ctrl.Result, error) {
+func (r *EtcdClusterReconciler) createClusterFromScratch(ctx context.Context, state State) (ctrl.Result, error) {
 	cm := factory.TemplateClusterStateConfigMap(state.instance, "new", state.desiredReplicas())
 	err := ctrl.SetControllerReference(state.instance, cm, r.Scheme)
 	if err != nil {
@@ -728,3 +732,9 @@
 func (r *EtcdClusterReconciler) promoteLearners(ctx context.Context) error {
 	return fmt.Errorf("not yet implemented")
 }
+
+// TODO!
+// nolint:unused
+func (r *EtcdClusterReconciler) handleDeletion(ctx context.Context, state State) error {
+	return fmt.Errorf("not yet implemented")
+}

internal/controller/etcdcluster_controller_new.go

@@ -333,7 +333,13 @@ func (r *ClusterReconciler) etcdClusterConfig(ctx context.Context, cluster *etcd
 
 // todo: implement this
 func (r *ClusterReconciler) createClusterFromScratch(ctx context.Context, state *observables) error {
-	panic("not implemented")
+	if err := r.createOrUpdateClusterStateConfigMap(ctx, state); err != nil {
+		return err
+	}
+	if err := r.createOrUpdateStatefulSet(ctx, state); err != nil {
+		return err
+	}
+	return nil
 }
 
 // todo: implement this

internal/controller/state.go

@@ -0,0 +1,7 @@
+package controller
+
+type State interface {
+	ClusterExists() bool
+	PendingDeletion() bool
+	GetEtcdCluster() error
+}