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package podset
import (
"context"
"reflect"
appv1alpha1 "github.com/xcoulon/podset-operator/pkg/apis/app/v1alpha1"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
"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_podset")
/**
* USER ACTION REQUIRED: This is a scaffold file intended for the user to modify with their own Controller
* business logic. Delete these comments after modifying this file.*
*/
// Add creates a new PodSet 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 {
return &ReconcilePodSet{client: mgr.GetClient(), scheme: mgr.GetScheme()}
}
// 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("podset-controller", mgr, controller.Options{Reconciler: r})
if err != nil {
return err
}
// Watch for changes to primary resource PodSet
err = c.Watch(&source.Kind{Type: &appv1alpha1.PodSet{}}, &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 PodSet
err = c.Watch(&source.Kind{Type: &corev1.Pod{}}, &handler.EnqueueRequestForOwner{
IsController: true,
OwnerType: &appv1alpha1.PodSet{},
})
if err != nil {
return err
}
return nil
}
var _ reconcile.Reconciler = &ReconcilePodSet{}
// ReconcilePodSet reconciles a PodSet object
type ReconcilePodSet struct {
// 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
}
// Reconcile reads that state of the cluster for a PodSet object and makes changes based on the state read
// and what is in the PodSet.Spec
// TODO(user): Modify this Reconcile function to implement your Controller logic. This example creates
// a Pod as an example
// 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 *ReconcilePodSet) Reconcile(request reconcile.Request) (reconcile.Result, error) {
reqLogger := log.WithValues("Request.Namespace", request.Namespace, "Request.Name", request.Name)
reqLogger.Info("Reconciling PodSet")
// Fetch the PodSet instance
podSet := &appv1alpha1.PodSet{}
err := r.client.Get(context.TODO(), request.NamespacedName, podSet)
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
return reconcile.Result{}, nil
}
// Error reading the object - requeue the request.
return reconcile.Result{}, err
}
// List all pods owned by this PodSet instance
lbls := labels.Set{
"app": podSet.Name,
"version": "v0.1",
}
existingPods := &corev1.PodList{}
err = r.client.List(context.TODO(),
&client.ListOptions{
Namespace: request.Namespace,
LabelSelector: labels.SelectorFromSet(lbls),
},
existingPods)
if err != nil {
reqLogger.Error(err, "failed to list existing pods in the podSet")
return reconcile.Result{}, err
}
existingPodNames := []string{}
// Count the pods that are pending or running as available
for _, pod := range existingPods.Items {
if pod.GetObjectMeta().GetDeletionTimestamp() != nil {
continue
}
if pod.Status.Phase == corev1.PodPending || pod.Status.Phase == corev1.PodRunning {
existingPodNames = append(existingPodNames, pod.GetObjectMeta().GetName())
}
}
reqLogger.Info("Checking podset", "expected replicas", podSet.Spec.Replicas, "Pod.Names", existingPodNames)
// Update the status if necessary
status := appv1alpha1.PodSetStatus{
PodNames: existingPodNames,
}
if !reflect.DeepEqual(podSet.Status, status) {
podSet.Status = status
err := r.client.Update(context.TODO(), podSet)
if err != nil {
reqLogger.Error(err, "failed to update the podSet")
return reconcile.Result{}, err
}
}
// Scale Down Pods
if int32(len(existingPodNames)) > podSet.Spec.Replicas {
// delete a pod. Just one at a time (this reconciler will be called again afterwards)
reqLogger.Info("Deleting a pod in the podset", "expected replicas", podSet.Spec.Replicas, "Pod.Names", existingPodNames)
pod := existingPods.Items[0]
err = r.client.Delete(context.TODO(), &pod)
if err != nil {
reqLogger.Error(err, "failed to delete a pod")
return reconcile.Result{}, err
}
}
// Scale Up Pods
if int32(len(existingPodNames)) < podSet.Spec.Replicas {
// create a new pod. Just one at a time (this reconciler will be called again afterwards)
reqLogger.Info("Adding a pod in the podset", "expected replicas", podSet.Spec.Replicas, "Pod.Names", existingPodNames)
pod := newPodForCR(podSet)
if err := controllerutil.SetControllerReference(podSet, pod, r.scheme); err != nil {
reqLogger.Error(err, "unable to set owner reference on new pod")
return reconcile.Result{}, err
}
err = r.client.Create(context.TODO(), pod)
if err != nil {
reqLogger.Error(err, "failed to create a pod")
return reconcile.Result{}, err
}
}
return reconcile.Result{Requeue: true}, nil
}
// newPodForCR returns a busybox pod with the same name/namespace as the cr
func newPodForCR(cr *appv1alpha1.PodSet) *corev1.Pod {
labels := map[string]string{
"app": cr.Name,
"version": "v0.1",
}
return &corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
GenerateName: cr.Name + "-pod",
Namespace: cr.Namespace,
Labels: labels,
},
Spec: corev1.PodSpec{
Containers: []corev1.Container{
{
Name: "busybox",
Image: "busybox",
Command: []string{"sleep", "3600"},
},
},
},
}
}
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