package memcached
import (
"context"
"reflect"
cachev1alpha1 "github.com/operator-framework/operator-sdk-samples/memcached-operator/pkg/apis/cache/v1alpha1"
sdk "github.com/ibm/composable/sdk"
appsv1 "k8s.io/api/apps/v1"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/types"
discovery "k8s.io/client-go/discovery"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/controller"
"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
"sigs.k8s.io/controller-runtime/pkg/handler"
"sigs.k8s.io/controller-runtime/pkg/manager"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"
"sigs.k8s.io/controller-runtime/pkg/source"
)
var log = logf.Log.WithName("controller_memcached")
// Add creates a new Memcached Controller and adds it to the Manager. The Manager will set fields on the Controller
// and Start it when the Manager is Started.
func Add(mgr manager.Manager) error {
return add(mgr, newReconciler(mgr))
}
// newReconciler returns a new reconcile.Reconciler
func newReconciler(mgr manager.Manager) reconcile.Reconciler {
cfg := mgr.GetConfig()
return &ReconcileMemcached{client: mgr.GetClient(), scheme: mgr.GetScheme(),
resolver: sdk.KubernetesResourceResolver{
Client: mgr.GetClient(),
ResourcesClient: discovery.NewDiscoveryClientForConfigOrDie(cfg),
},
}
}
// add adds a new Controller to mgr with r as the reconcile.Reconciler
func add(mgr manager.Manager, r reconcile.Reconciler) error {
// Create a new controller
c, err := controller.New("memcached-controller", mgr, controller.Options{Reconciler: r})
if err != nil {
return err
}
// Watch for changes to primary resource Memcached
err = c.Watch(&source.Kind{Type: &cachev1alpha1.Memcached{}}, &handler.EnqueueRequestForObject{})
if err != nil {
return err
}
// TODO(user): Modify this to be the types you create that are owned by the primary resource
// Watch for changes to secondary resource Pods and requeue the owner Memcached
err = c.Watch(&source.Kind{Type: &appsv1.Deployment{}}, &handler.EnqueueRequestForOwner{
IsController: true,
OwnerType: &cachev1alpha1.Memcached{},
})
if err != nil {
return err
}
err = c.Watch(&source.Kind{Type: &corev1.Service{}}, &handler.EnqueueRequestForOwner{
IsController: true,
OwnerType: &cachev1alpha1.Memcached{},
})
if err != nil {
return err
}
return nil
}
var _ reconcile.Reconciler = &ReconcileMemcached{}
// ReconcileMemcached reconciles a Memcached object
type ReconcileMemcached struct {
// TODO: Clarify the split client
// This client, initialized using mgr.Client() above, is a split client
// that reads objects from the cache and writes to the apiserver
client client.Client
scheme *runtime.Scheme
resolver sdk.ResolveObject
}
// Reconcile reads that state of the cluster for a Memcached object and makes changes based on the state read
// and what is in the Memcached.Spec
// TODO(user): Modify this Reconcile function to implement your Controller logic. This example creates
// a Memcached Deployment for each Memcached CR
// Note:
// The Controller will requeue the Request to be processed again if the returned error is non-nil or
// Result.Requeue is true, otherwise upon completion it will remove the work from the queue.
func (r *ReconcileMemcached) Reconcile(request reconcile.Request) (reconcile.Result, error) {
reqLogger := log.WithValues("Request.Namespace", request.Namespace, "Request.Name", request.Name)
reqLogger.Info("Reconciling Memcached.")
// Fetch the Memcached instance
memcached := &cachev1alpha1.Memcached{}
err := r.client.Get(context.TODO(), request.NamespacedName, memcached)
if err != nil {
if errors.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
reqLogger.Info("Memcached resource not found. Ignoring since object must be deleted.")
return reconcile.Result{}, nil
}
// Error reading the object - requeue the request.
reqLogger.Error(err, "Failed to get Memcached.")
return reconcile.Result{}, err
}
// Resolve the memcached instance
resolved := &cachev1alpha1.MemcachedResolved{}
err = r.resolver.ResolveObject(context.TODO(), memcached, resolved)
// Fix this to have more info on the nature of the error
if err != nil {
if sdk.IsRefNotFound(err) {
return reconcile.Result{}, err
}
return reconcile.Result{}, nil
}
// Check if the Deployment already exists, if not create a new one
deployment := &appsv1.Deployment{}
err = r.client.Get(context.TODO(), types.NamespacedName{Name: memcached.Name, Namespace: memcached.Namespace}, deployment)
if err != nil && errors.IsNotFound(err) {
// Define a new Deployment
dep := r.deploymentForMemcached(resolved)
reqLogger.Info("Creating a new Deployment.", "Deployment.Namespace", dep.Namespace, "Deployment.Name", dep.Name)
err = r.client.Create(context.TODO(), dep)
if err != nil {
reqLogger.Error(err, "Failed to create new Deployment.", "Deployment.Namespace", dep.Namespace, "Deployment.Name", dep.Name)
return reconcile.Result{}, err
}
// Deployment created successfully - return and requeue
// NOTE: that the requeue is made with the purpose to provide the deployment object for the next step to ensure the deployment size is the same as the spec.
// Also, you could GET the deployment object again instead of requeue if you wish. See more over it here: https://godoc.org/sigs.k8s.io/controller-runtime/pkg/reconcile#Reconciler
return reconcile.Result{Requeue: true}, nil
} else if err != nil {
reqLogger.Error(err, "Failed to get Deployment.")
return reconcile.Result{}, err
}
// Ensure the deployment size is the same as the spec
size := resolved.Spec.Size
if *deployment.Spec.Replicas != size {
deployment.Spec.Replicas = &size
err = r.client.Update(context.TODO(), deployment)
if err != nil {
reqLogger.Error(err, "Failed to update Deployment.", "Deployment.Namespace", deployment.Namespace, "Deployment.Name", deployment.Name)
return reconcile.Result{}, err
}
}
// Check if the Service already exists, if not create a new one
// NOTE: The Service is used to expose the Deployment. However, the Service is not required at all for the memcached example to work. The purpose is to add more examples of what you can do in your operator project.
service := &corev1.Service{}
err = r.client.Get(context.TODO(), types.NamespacedName{Name: memcached.Name, Namespace: memcached.Namespace}, service)
if err != nil && errors.IsNotFound(err) {
// Define a new Service object
ser := r.serviceForMemcached(memcached)
reqLogger.Info("Creating a new Service.", "Service.Namespace", ser.Namespace, "Service.Name", ser.Name)
err = r.client.Create(context.TODO(), ser)
if err != nil {
reqLogger.Error(err, "Failed to create new Service.", "Service.Namespace", ser.Namespace, "Service.Name", ser.Name)
return reconcile.Result{}, err
}
} else if err != nil {
reqLogger.Error(err, "Failed to get Service.")
return reconcile.Result{}, err
}
// Update the Memcached status with the pod names
// List the pods for this memcached's deployment
podList := &corev1.PodList{}
listOpts := []client.ListOption{
client.InNamespace(memcached.Namespace),
client.MatchingLabels(labelsForMemcached(memcached.Name)),
}
err = r.client.List(context.TODO(), podList, listOpts...)
if err != nil {
reqLogger.Error(err, "Failed to list pods.", "Memcached.Namespace", memcached.Namespace, "Memcached.Name", memcached.Name)
return reconcile.Result{}, err
}
podNames := getPodNames(podList.Items)
// Update status.Nodes if needed
if !reflect.DeepEqual(podNames, memcached.Status.Nodes) {
memcached.Status.Nodes = podNames
err := r.client.Status().Update(context.TODO(), memcached)
if err != nil {
reqLogger.Error(err, "Failed to update Memcached status.")
return reconcile.Result{}, err
}
}
return reconcile.Result{}, nil
}
// deploymentForMemcached returns a memcached Deployment object
func (r *ReconcileMemcached) deploymentForMemcached(m *cachev1alpha1.MemcachedResolved) *appsv1.Deployment {
ls := labelsForMemcached(m.Name)
replicas := m.Spec.Size
dep := &appsv1.Deployment{
ObjectMeta: metav1.ObjectMeta{
Name: m.Name,
Namespace: m.Namespace,
},
Spec: appsv1.DeploymentSpec{
Replicas: &replicas,
Selector: &metav1.LabelSelector{
MatchLabels: ls,
},
Template: corev1.PodTemplateSpec{
ObjectMeta: metav1.ObjectMeta{
Labels: ls,
},
Spec: corev1.PodSpec{
Containers: []corev1.Container{{
Image: "memcached:1.4.36-alpine",
Name: "memcached",
Command: []string{"memcached", "-m=64", "-o", "modern", "-v"},
Ports: []corev1.ContainerPort{{
ContainerPort: 11211,
Name: "memcached",
}},
}},
},
},
},
}
// Set Memcached instance as the owner of the Deployment.
controllerutil.SetControllerReference(m, dep, r.scheme)
return dep
}
// serviceForMemcached function takes in a Memcached object and returns a Service for that object.
func (r *ReconcileMemcached) serviceForMemcached(m *cachev1alpha1.Memcached) *corev1.Service {
ls := labelsForMemcached(m.Name)
ser := &corev1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: m.Name,
Namespace: m.Namespace,
},
Spec: corev1.ServiceSpec{
Selector: ls,
Ports: []corev1.ServicePort{
{
Port: 11211,
Name: m.Name,
},
},
},
}
// Set Memcached instance as the owner of the Service.
controllerutil.SetControllerReference(m, ser, r.scheme)
return ser
}
// labelsForMemcached returns the labels for selecting the resources
// belonging to the given memcached CR name.
func labelsForMemcached(name string) map[string]string {
return map[string]string{"app": "memcached", "memcached_cr": name}
}
// getPodNames returns the pod names of the array of pods passed in
func getPodNames(pods []corev1.Pod) []string {
var podNames []string
for _, pod := range pods {
podNames = append(podNames, pod.Name)
}
return podNames
}