Modify the PodSet controller logic at go/src/github.com/redhat/podset-operator/pkg/controller/podset/podset_controller.go
package podset
import (
"context"
"reflect"
appv1alpha1 "github.com/redhat/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"
logf "sigs.k8s.io/controller-runtime/pkg/log"
"sigs.k8s.io/controller-runtime/pkg/manager"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
"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
}
// blank assignment to verify that ReconcilePodSet implements reconcile.Reconciler
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
instance := &appv1alpha1.PodSet{}
err := r.client.Get(context.TODO(), request.NamespacedName, instance)
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
podSet := instance
podList := &corev1.PodList{}
lbs := map[string]string{
"app": podSet.Name,
"version": "v0.1",
}
labelSelector := labels.SelectorFromSet(lbs)
listOps := &client.ListOptions{Namespace: podSet.Namespace, LabelSelector: labelSelector}
if err = r.client.List(context.TODO(), podList, listOps); err != nil {
return reconcile.Result{}, err
}
// Count the pods that are pending or running as available
var available []corev1.Pod
for _, pod := range podList.Items {
if pod.ObjectMeta.DeletionTimestamp != nil {
continue
}
if pod.Status.Phase == corev1.PodRunning || pod.Status.Phase == corev1.PodPending {
available = append(available, pod)
}
}
numAvailable := int32(len(available))
availableNames := []string{}
for _, pod := range available {
availableNames = append(availableNames, pod.ObjectMeta.Name)
}
// Update the status if necessary
status := appv1alpha1.PodSetStatus{
PodNames: availableNames,
}
if !reflect.DeepEqual(podSet.Status, status) {
podSet.Status = status
err = r.client.Status().Update(context.TODO(), podSet)
if err != nil {
reqLogger.Error(err, "Failed to update PodSet status")
return reconcile.Result{}, err
}
}
if numAvailable > podSet.Spec.Replicas {
reqLogger.Info("Scaling down pods", "Currently available", numAvailable, "Required replicas", podSet.Spec.Replicas)
diff := numAvailable - podSet.Spec.Replicas
dpods := available[:diff]
for _, dpod := range dpods {
err = r.client.Delete(context.TODO(), &dpod)
if err != nil {
reqLogger.Error(err, "Failed to delete pod", "pod.name", dpod.Name)
return reconcile.Result{}, err
}
}
return reconcile.Result{Requeue: true}, nil
}
if numAvailable < podSet.Spec.Replicas {
reqLogger.Info("Scaling up pods", "Currently available", numAvailable, "Required replicas", podSet.Spec.Replicas)
// Define a new Pod object
pod := newPodForCR(podSet)
// Set PodSet instance as the owner and controller
if err := controllerutil.SetControllerReference(podSet, pod, r.scheme); err != nil {
return reconcile.Result{}, err
}
err = r.client.Create(context.TODO(), pod)
if err != nil {
reqLogger.Error(err, "Failed to create pod", "pod.name", pod.Name)
return reconcile.Result{}, err
}
return reconcile.Result{Requeue: true}, nil
}
return reconcile.Result{}, 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"},
},
},
},
}
}
You can easily update this file by running the following command:
wget -q https://raw.githubusercontent.com/openshift-labs/learn-katacoda/master/operatorframework/go-operator-podset/assets/podset_controller.go -O pkg/controller/podset/podset_controller.go
