wildflyserver_controller.go

/*
Copyright 2022.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package controllers

import (
	"context"
	"errors"
	"fmt"
	"github.com/go-logr/logr"
	routev1 "github.com/openshift/api/route/v1"
	monitoringv1 "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"
	"github.com/wildfly/wildfly-operator/pkg/resources"
	"github.com/wildfly/wildfly-operator/pkg/resources/routes"
	"github.com/wildfly/wildfly-operator/pkg/resources/servicemonitors"
	"github.com/wildfly/wildfly-operator/pkg/resources/services"
	"github.com/wildfly/wildfly-operator/pkg/resources/statefulsets"
	wildflyutil "github.com/wildfly/wildfly-operator/pkg/util"
	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	apiErrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/client-go/tools/record"
	"os"
	"reflect"
	"sigs.k8s.io/controller-runtime/pkg/handler"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
	"sigs.k8s.io/controller-runtime/pkg/source"
	"strconv"
	"strings"

	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"

	wildflyv1alpha1 "github.com/wildfly/wildfly-operator/api/v1alpha1"
)

const (
	requeueOff   = iota // 0
	requeueLater = iota // 1
	requeueNow   = iota // 2
)

// WildFlyServerReconciler reconciles a WildFlyServer object
type WildFlyServerReconciler struct {
	Client   client.Client
	Scheme   *runtime.Scheme
	Recorder record.EventRecorder
	// returns true if the operator is running on OpenShift
	IsOpenShift bool
	Log         logr.Logger
}

// Reconcile is part of the main kubernetes reconciliation loop which aims to
// move the current state of the cluster closer to the desired state.
// TODO(user): Modify the Reconcile function to compare the state specified by
// the WildFlyServer object against the actual cluster state, and then
// perform operations to make the cluster state reflect the state specified by
// the user.
//
// For more details, check Reconcile and its Result here:
// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.7.0/pkg/reconcile
func (r *WildFlyServerReconciler) Reconcile(ctx context.Context, request ctrl.Request) (ctrl.Result, error) {
	log := r.Log.WithValues("name", request.NamespacedName)

	log.Info("Reconciling WildFlyServer")

	// Fetch the WildFlyServer instance
	wildflyServer := &wildflyv1alpha1.WildFlyServer{}
	err := r.Client.Get(ctx, request.NamespacedName, wildflyServer)
	if err != nil {
		if apiErrors.IsNotFound(err) {
			// Request object not found, could have been deleted after reconcile request.
			// Owned objects are automatically garbage collected. For additional cleanup logic use finalizers.
			// Return and don't requeue
			return reconcile.Result{}, nil
		}
		// Error reading the object - requeue the request.
		return reconcile.Result{}, err
	}

	if ok, err := validate(wildflyServer); !ok {
		return r.manageError(wildflyServer, err)
	}

	// Use the unique CR name as the selector label, must be implemented in the pods as well.
	wildflyServer.Status.Selector = fmt.Sprintf("app.kubernetes.io/name=%s", wildflyServer.Name)

	// If statefulset was deleted during processing recovery scaledown the number of replicas in WildflyServer spec
	//  does not defines the number of pods which should be left active until recovered
	desiredReplicaSizeForNewStatefulSet := wildflyServer.Spec.Replicas + wildflyServer.Status.ScalingdownPods

	// Check if the statefulSet already exists, if not create a new one
	statefulSet, err := statefulsets.GetOrCreateNewStatefulSet(wildflyServer, r.Client, r.Scheme,
		LabelsForWildFly(wildflyServer), desiredReplicaSizeForNewStatefulSet, r.IsOpenShift)
	if err != nil {
		return reconcile.Result{}, err
	} else if statefulSet == nil {
		return reconcile.Result{Requeue: true}, nil
	}

	// List of pods which belongs under this WildflyServer instance
	podList, err := GetPodsForWildFly(r, wildflyServer)
	if err != nil {
		log.Error(err, "Failed to list pods.", "WildFlyServer.Namespace", wildflyServer.Namespace, "WildFlyServer.Name", wildflyServer.Name)
		return reconcile.Result{}, err
	}
	wildflyServerSpecSize := wildflyServer.Spec.Replicas
	statefulsetSpecSize := *statefulSet.Spec.Replicas
	numberOfDeployedPods := int32(len(podList.Items))
	numberOfPodsToScaleDown := statefulsetSpecSize - wildflyServerSpecSize // difference between desired pod count and the current number of pods

	// If there are pods clean and have been removed, remove the status now
	if updated, err := r.cleanUpPodStatus(wildflyServer, podList); err != nil {
		log.Error(err, "Failed to clean up pod status after scaling down", "WildFlyServer.Name", wildflyServer.Name)
		return reconcile.Result{}, err
	} else if updated {
		return reconcile.Result{Requeue: true}, nil
	}

	// if the number of desired replica size (aka. WildflyServer.Spec.Replicas) is different from the number of active pods
	//  and the statefulset replica size was already changed to follow the value defined by the wildflyserver spec then wait for sts to reconcile
	if statefulsetSpecSize == wildflyServerSpecSize && numberOfDeployedPods != wildflyServerSpecSize {
		log.Info("Number of pods does not match the WildFlyServer specification. Waiting to get numbers in sync.",
			"WildflyServer specification", wildflyServer.Name, "Expected number of pods", wildflyServerSpecSize, "Number of deployed pods", numberOfDeployedPods,
			"StatefulSet spec size", statefulsetSpecSize)
		return reconcile.Result{Requeue: true}, nil
	}
	// the recovers scaledown process requires all pods will be active and running otherwise it's not able to clean them
	if numberOfDeployedPods < statefulsetSpecSize {
		log.Info("Number of pods is lower than the StatefulSet replica size. Waiting to get number in sync.",
			"Number of deployed pods", numberOfDeployedPods, "StatefulSet spec size", statefulsetSpecSize)
		return reconcile.Result{Requeue: true}, nil
	}

	// Processing scaled down
	//   updating scaling-down pods for not being requests through loadbalancer
	updated, err := r.setLabelAsDisabled(wildflyServer, log, resources.MarkerOperatedByLoadbalancer, int(numberOfPodsToScaleDown), podList)
	if updated || err != nil { // labels were updated (updated == true) or some error occured (err != nil)
		return reconcile.Result{Requeue: updated}, err
	}
	// Processing recovery on pods which are planned to be removed because of scale down is in progress now
	reconcileRecovery, err := r.processTransactionRecoveryScaleDown(log, wildflyServer, int(numberOfPodsToScaleDown), podList)
	if reconcileRecovery == requeueNow { // server state was updated (or/and some error could happen), we need to reconcile
		return reconcile.Result{Requeue: true}, err
	}
	if err != nil {
		log.Error(err, "Failures during scaling down recovery processing", "Desired replica size", wildflyServerSpecSize,
			"Number of pods to be removed", numberOfPodsToScaleDown)
	}

	reconcileStatefulSet, err := r.checkStatefulSet(wildflyServer, statefulSet, podList)
	if reconcileStatefulSet == requeueNow {
		return reconcile.Result{Requeue: true}, err
	} else if err != nil {
		return reconcile.Result{}, err
	}

	// Check if the cluster service already exists, if not create a new one
	clusterService, err := services.CreateOrUpdateClusterService(wildflyServer, r.Client, r.Scheme, LabelsForWildFly(wildflyServer))
	if err != nil {
		return reconcile.Result{}, err
	} else if clusterService == nil {
		return reconcile.Result{Requeue: true}, nil
	}
	// Check if the headless service already exists, if not create a new one
	if headlessService, err := services.CreateOrUpdateHeadlessService(wildflyServer, r.Client, r.Scheme, LabelsForWildFly(wildflyServer)); err != nil {
		return reconcile.Result{}, err
	} else if headlessService == nil {
		return reconcile.Result{Requeue: true}, nil
	}
	// Check if the admin service already exists, if not create a new one
	if adminService, err := services.CreateOrUpdateAdminService(wildflyServer, r.Client, r.Scheme, LabelsForWildFly(wildflyServer)); err != nil {
		return reconcile.Result{}, err
	} else if adminService == nil {
		return reconcile.Result{Requeue: true}, nil
	}

	// Check if the HTTP route must be created
	var route *routev1.Route
	if r.IsOpenShift {
		if !wildflyServer.Spec.DisableHTTPRoute {
			if route, err = routes.GetOrCreateNewRoute(wildflyServer, r.Client, r.Scheme, LabelsForWildFly(wildflyServer)); err != nil {
				return reconcile.Result{}, err
			} else if route == nil {
				return reconcile.Result{Requeue: true}, nil
			}
		} else {
			// delete the route that may have been created by a previous generation of the WildFlyServer
			if deleted, err := routes.DeleteExistingRoute(wildflyServer, r.Client); err != nil {
				return reconcile.Result{}, err
			} else if deleted {
				return reconcile.Result{}, nil
			}
		}
	}

	// create a Prometheus ServiceMonitor (if the resource exists on the cluster)
	if hasServiceMonitor() {
		if serviceMonitor, err := servicemonitors.GetOrCreateNewServiceMonitor(wildflyServer, r.Client, r.Scheme, LabelsForWildFly(wildflyServer)); err != nil {
			return reconcile.Result{}, err
		} else if serviceMonitor == nil {
			return reconcile.Result{Requeue: true}, nil
		}
	}

	// Update WildFly Server host status
	updateWildflyServer := false
	if r.IsOpenShift {
		if !wildflyServer.Spec.DisableHTTPRoute {
			hosts := make([]string, len(route.Status.Ingress))
			for i, ingress := range route.Status.Ingress {
				hosts[i] = ingress.Host
			}
			if !reflect.DeepEqual(hosts, wildflyServer.Status.Hosts) {
				updateWildflyServer = true
				wildflyServer.Status.Hosts = hosts
				log.Info("Updating hosts", "WildFlyServer", wildflyServer.Name, "WildflyServer hosts", wildflyServer.Status.Hosts)
			}
		} else {
			// if HTTP routes have been disabled, remove the hosts field from the status
			if len(wildflyServer.Status.Hosts) > 0 {
				updateWildflyServer = true
				wildflyServer.Status.Hosts = nil
				log.Info("Removing hosts", "WildFlyServer", wildflyServer.Name)
			}
		}
	}

	if wildflyServer.Status.ScalingdownPods != numberOfPodsToScaleDown {
		wildflyServer.Status.ScalingdownPods = numberOfPodsToScaleDown
		updateWildflyServer = true
	}
	// Ensure the pod states are up to date by switching it to active when statefulset comes back in size (scales up)
	if numberOfPodsToScaleDown <= 0 {
		for k, v := range wildflyServer.Status.Pods {
			if v.State != wildflyv1alpha1.PodStateActive { // was in scale down processing
				wildflyServer.Status.Pods[k].State = wildflyv1alpha1.PodStateActive
				updateWildflyServer = true
				// the non-active pod may be in the middle of the scale down process, we need to completely refresh it
				for _, podItem := range podList.Items {
					if podItem.Name == v.Name {
						resources.Delete(wildflyServer, r.Client, &podItem)
					}
				}
			}
		}
	}

	// Update WildFly Server pod status based on the number of StatefulSet pods
	reconcileStatus, podsStatus := getPodStatus(podList.Items, wildflyServer.Status.Pods)
	if !reflect.DeepEqual(podsStatus, wildflyServer.Status.Pods) {
		updateWildflyServer = true
		wildflyServer.Status.Pods = podsStatus
		log.Info("Updating the pod status with new status", "Pod statuses", podsStatus)
	}

	if wildflyServer.Status.Replicas != statefulSet.Status.Replicas {
		wildflyServer.Status.Replicas = statefulSet.Status.Replicas
		updateWildflyServer = true
	}

	if updateWildflyServer {
		if err := resources.UpdateWildFlyServerStatus(wildflyServer, r.Client); err != nil {
			log.Error(err, "Failed to update WildFlyServer status.")
			return reconcile.Result{}, err
		}
		reconcileStatus = true
	}

	// requeue the reconcile loop if pod status changed, or the recovery/statefulset asked to reconcile later
	requeue := reconcileStatus || reconcileRecovery >= requeueLater || reconcileStatefulSet >= requeueLater
	return reconcile.Result{Requeue: requeue}, nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *WildFlyServerReconciler) SetupWithManager(mgr ctrl.Manager) error {
	r.Log.Info("Setting up with manager")
	builder := ctrl.NewControllerManagedBy(mgr).
		For(&wildflyv1alpha1.WildFlyServer{})

	builder.Owns(&corev1.Service{})

	if hasServiceMonitor() {
		builder.Owns(&monitoringv1.ServiceMonitor{})
	}

	//watch for Route only on OpenShift
	if r.IsOpenShift {
		builder.Owns(&routev1.Route{})
	}

	builder.Watches(&source.Kind{Type: &appsv1.StatefulSet{}}, &handler.EnqueueRequestForOwner{OwnerType: &wildflyv1alpha1.WildFlyServer{}, IsController: false})
	return builder.Complete(r)
}

// checkStatefulSet checks if the statefulset is up to date with the current WildFlyServerSpec.
// it returns true if a reconcile result must be returned.
// A non-nil error if an error happens while updating/deleting the statefulset.
func (r *WildFlyServerReconciler) checkStatefulSet(wildflyServer *wildflyv1alpha1.WildFlyServer, foundStatefulSet *appsv1.StatefulSet,
	podList *corev1.PodList) (mustReconcile int, err error) {

	var update bool
	var requeue = requeueOff
	// Ensure the statefulset replicas is up to date (driven by scaledown processing)
	wildflyServerSpecSize := wildflyServer.Spec.Replicas
	desiredStatefulSetReplicaSize := wildflyServerSpecSize
	// - for scale up
	if wildflyServerSpecSize > *foundStatefulSet.Spec.Replicas {
		r.Log.Info("Scaling up and updating replica size to "+strconv.Itoa(int(wildflyServerSpecSize)),
			"StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
		foundStatefulSet.Spec.Replicas = &desiredStatefulSetReplicaSize
		update = true
	}
	// - for scale down
	if wildflyServerSpecSize < *foundStatefulSet.Spec.Replicas {
		r.Log.Info("For statefulset scaling down need to verify if pods were cleaned by recovery",
			"StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
		// Change the number of replicas in statefulset, changing based on the pod state
		nameToPodState := make(map[string]string)
		for _, v := range wildflyServer.Status.Pods {
			nameToPodState[v.Name] = v.State
		}
		numberOfPods := len(podList.Items)
		numberOfPodsToShutdown := 0
		// Searching the array of deployed pods from top to down, if the pod with the highest number is clean
		//   then the statefulset replica size can be decreased by 1
		for index := numberOfPods - 1; index >= 0; index-- {
			podItem := podList.Items[index]
			if podStatus, exist := nameToPodState[podItem.Name]; exist {
				if podStatus == wildflyv1alpha1.PodStateScalingDownClean {
					// the pod with the highest number is clean to go
					numberOfPodsToShutdown++
				} else {
					// the pod with the highest number can't be removed, waiting for the next reconcile loop
					break
				}
			}
		}
		// Scaling down statefulset to number of pods that were cleaned by recovery
		calculatedStatefulSetReplicaSize := int32(numberOfPods - numberOfPodsToShutdown)
		desiredStatefulSetReplicaSize = calculatedStatefulSetReplicaSize
		if wildflyServerSpecSize <= calculatedStatefulSetReplicaSize && *foundStatefulSet.Spec.Replicas > calculatedStatefulSetReplicaSize {
			r.Log.Info("Scaling down and updating replica size to "+strconv.Itoa(int(calculatedStatefulSetReplicaSize)),
				"StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
			foundStatefulSet.Spec.Replicas = &desiredStatefulSetReplicaSize
			update = true
		}
		// There are some unclean pods which can't be scaled down
		if wildflyServerSpecSize < calculatedStatefulSetReplicaSize {
			r.Log.Info("Statefulset was not scaled to the desired replica size "+strconv.Itoa(int(wildflyServerSpecSize))+
				" (current StatefulSet size: "+strconv.Itoa(int(calculatedStatefulSetReplicaSize))+
				"). Transaction recovery scaledown process has not cleaned all pods. Please, check status of the WildflyServer "+wildflyServer.Name,
				"StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
			r.Recorder.Event(wildflyServer, corev1.EventTypeWarning, "WildFlyServerScaledown",
				"Transaction recovery slowed down the scaledown.")
			requeue = requeueLater
		}
	}

	if !resources.IsCurrentGeneration(wildflyServer, foundStatefulSet) {
		statefulSet := statefulsets.NewStatefulSet(wildflyServer, LabelsForWildFly(wildflyServer), desiredStatefulSetReplicaSize, r.IsOpenShift)
		delete := false
		// changes to VolumeClaimTemplates can not be updated and requires a delete/create of the statefulset
		if len(statefulSet.Spec.VolumeClaimTemplates) > 0 {
			if len(foundStatefulSet.Spec.VolumeClaimTemplates) == 0 {
				// existing stateful set does not have a VCT
				delete = true
			} else {
				foundVCT := foundStatefulSet.Spec.VolumeClaimTemplates[0]
				vct := statefulSet.Spec.VolumeClaimTemplates[0]

				if foundVCT.Name != vct.Name ||
					!reflect.DeepEqual(foundVCT.Spec.AccessModes, vct.Spec.AccessModes) ||
					!reflect.DeepEqual(foundVCT.Spec.Resources, vct.Spec.Resources) {
					delete = true
				}
			}
		} else {
			if len(foundStatefulSet.Spec.VolumeClaimTemplates) != 0 {
				// existing stateful set has a VCT while updated statefulset does not
				delete = true
			}
		}

		if delete {
			// VolumeClaimTemplates has changed, the statefulset can not be updated and must be deleted
			if err = resources.Delete(wildflyServer, r.Client, foundStatefulSet); err != nil {
				r.Log.Error(err, "Failed to Delete StatefulSet.", "StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
				return requeueNow, err
			}
			r.Log.Info("Deleting StatefulSet that is not up to date with the WildFlyServer StorageSpec", "StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
			return requeueNow, nil
		}

		// all other changes are in the spec Template or Replicas and the statefulset can be updated
		foundStatefulSet.Spec.Template = statefulSet.Spec.Template
		foundStatefulSet.Spec.Replicas = &desiredStatefulSetReplicaSize
		foundStatefulSet.Annotations[resources.MarkerServerGeneration] = strconv.FormatInt(wildflyServer.Generation, 10)
		if err = resources.Update(wildflyServer, r.Client, foundStatefulSet); err != nil {
			r.Log.Error(err, "Failed to Update StatefulSet.", "StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
			return requeueNow, err
		}
		r.Log.Info("Updating StatefulSet to be up to date with the WildFlyServer Spec", "StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
		return requeueNow, nil
	}

	if update {
		r.Log.Info("Updating statefulset", "StatefulSet.Replicas", foundStatefulSet.Spec.Replicas)
		if err = resources.Update(wildflyServer, r.Client, foundStatefulSet); err != nil {
			r.Log.Error(err, "Failed to update StatefulSet.", "StatefulSet.Namespace", foundStatefulSet.Namespace, "StatefulSet.Name", foundStatefulSet.Name)
			return requeueNow, err
		}
		return requeueNow, nil
	}

	return requeue, nil
}

func (r *WildFlyServerReconciler) manageError(w *wildflyv1alpha1.WildFlyServer, err error) (reconcile.Result, error) {
	if err == nil {
		r.Recorder.Event(w, corev1.EventTypeWarning, "WildFlyProcessingError", "Unknown Error")
		return reconcile.Result{}, err
	}

	r.Recorder.Event(w, corev1.EventTypeWarning, "WildFlyProcessingError", err.Error())
	return reconcile.Result{}, err
}

func validate(w *wildflyv1alpha1.WildFlyServer) (bool, error) {
	if w.Spec.BootableJar && w.Spec.StandaloneConfigMap != nil {
		return false, errors.New("Bootable JAR server does not support custom server configuration file via config map.")
	}
	return true, nil
}

// matches checks if the envVar from the WildFlyServerSpec matches the same env var from the container.
// If it does not match, it updates the container EnvVar with the fields from the WildFlyServerSpec and return false.
func matches(container *corev1.Container, envVar corev1.EnvVar) bool {
	for index, e := range container.Env {
		if envVar.Name == e.Name {
			if !reflect.DeepEqual(envVar, e) {
				container.Env[index] = envVar
				return false
			}
			return true
		}
	}
	//append new spec env to container's env var
	container.Env = append(container.Env, envVar)
	return false
}

// GetPodsForWildFly lists pods which belongs to the WildFly server
//
//	the pods are differentiated based on the selectors
func GetPodsForWildFly(r *WildFlyServerReconciler, w *wildflyv1alpha1.WildFlyServer) (*corev1.PodList, error) {
	podList := &corev1.PodList{}

	listOpts := []client.ListOption{
		client.InNamespace(w.Namespace),
		client.MatchingLabels(LabelsForWildFly(w)),
	}
	err := r.Client.List(context.TODO(), podList, listOpts...)

	if err == nil {
		// sorting pods by number in the name
		wildflyutil.SortPodListByName(podList)
	}
	return podList, err
}

func getWildflyServerPodStatusByName(w *wildflyv1alpha1.WildFlyServer, podName string) *wildflyv1alpha1.PodStatus {
	for index, podStatus := range w.Status.Pods {
		if podName == podStatus.Name {
			return &w.Status.Pods[index]
		}
	}
	return nil
}

// getPodStatus returns the pod names of the array of pods passed in
func getPodStatus(pods []corev1.Pod, originalPodStatuses []wildflyv1alpha1.PodStatus) (bool, []wildflyv1alpha1.PodStatus) {
	var requeue = false
	var podStatuses []wildflyv1alpha1.PodStatus
	podStatusesOriginalMap := make(map[string]wildflyv1alpha1.PodStatus)
	for _, v := range originalPodStatuses {
		podStatusesOriginalMap[v.Name] = v
	}
	for _, pod := range pods {
		podState := wildflyv1alpha1.PodStateActive
		if value, exists := podStatusesOriginalMap[pod.Name]; exists {
			podState = value.State
		}
		podStatuses = append(podStatuses, wildflyv1alpha1.PodStatus{
			Name:  pod.Name,
			PodIP: pod.Status.PodIP,
			State: podState,
		})
		if pod.Status.PodIP == "" {
			requeue = true
		}
	}
	return requeue, podStatuses
}

// LabelsForWildFly return a map of labels that are used for identification
//
//	of objects belonging to the particular WildflyServer instance
func LabelsForWildFly(w *wildflyv1alpha1.WildFlyServer) map[string]string {
	labels := make(map[string]string)
	labels["app.kubernetes.io/name"] = w.Name
	labels["app.kubernetes.io/managed-by"] = os.Getenv("LABEL_APP_MANAGED_BY")
	labels["app.openshift.io/runtime"] = os.Getenv("LABEL_APP_RUNTIME")
	if w.Labels != nil {
		for labelKey, labelValue := range w.Labels {
			labels[labelKey] = labelValue
		}
	}
	return labels
}

// errorIsMatchesForKind return true if the error is that there is no matches for the kind & version
func errorIsNoMatchesForKind(err error, kind string, version string) bool {
	return strings.HasPrefix(err.Error(), fmt.Sprintf("no matches for kind \"%s\" in version \"%s\"", kind, version))
}

//// hasServiceMonitor checks if ServiceMonitor is registered in the cluster.
//func hasServiceMonitor(config *rest.Config) (bool, error) {
//	dc := discovery.NewDiscoveryClientForConfigOrDie(config)
//	apiVersion := "monitoring.coreos.com/v1"
//	kind := "ServiceMonitor"
//
//	return k8sutil.ResourceExists(dc, apiVersion, kind)
//}

// hasServiceMonitor checks if ServiceMonitor kind is registered in the cluster.
func hasServiceMonitor() bool {
	return resources.CustomResourceDefinitionExists(schema.GroupVersionKind{
		Group:   "monitoring.coreos.com",
		Version: monitoringv1.Version,
		Kind:    monitoringv1.ServiceMonitorsKind,
	})
}

// cleanUpPodStatus clean up the pod status for pods that have been scaled down to be consistent with the current list of pods read from the cluster
func (r *WildFlyServerReconciler) cleanUpPodStatus(w *wildflyv1alpha1.WildFlyServer, podList *corev1.PodList) (bool, error) {
	var result []wildflyv1alpha1.PodStatus
Outer:
	for _, v := range w.Status.Pods {
		if v.State == wildflyv1alpha1.PodStateScalingDownClean {
			for _, pv := range podList.Items {
				if pv.Name == v.Name {
					result = append(result, v)
					continue Outer
				}
			}
		} else {
			result = append(result, v)
		}
	}
	totalOld := len(w.Status.Pods)
	totalNew := len(result)
	if totalOld != totalNew {
		patch := client.MergeFrom(w.DeepCopy())
		w.Status.Pods = result
		delta := totalOld - totalNew
		w.Status.Replicas = Max(w.Status.Replicas-int32(delta), 0)
		w.Status.ScalingdownPods = Max(w.Status.ScalingdownPods-int32(delta), 0)
		if err := r.Client.Status().Patch(context.Background(), w, patch); err != nil {
			return false, err
		}
		return true, nil
	}
	return false, nil
}

func Max(x, y int32) int32 {
	if x < y {
		return y
	}
	return x
}