operator-sdk-memcached-operator-implement-controller-4-update-status-with-pod-name.go

import (
    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/types"
    "reflect" //added

    "context"

    cachev1alpha1 "github.com/example/memcached-operator/api/v1alpha1"
    "github.com/go-logr/logr"
    "k8s.io/apimachinery/pkg/runtime"
    ctrl "sigs.k8s.io/controller-runtime"
    "sigs.k8s.io/controller-runtime/pkg/client"
)
...

func (r *MemcachedReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
    log := r.Log.WithValues("memcached", req.NamespacedName)

    // 1. Fetch the Memcached instance
        // implemented
    // 2. Check if the deployment already exists, if not create a new one
        // implemented
    // 3. Ensure the deployment size is the same as the spec
        // implemented

    // 4. 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)),
    }
    if err = r.List(ctx, podList, listOpts...); err != nil {
        log.Error(err, "4. Update the Memcached status with the pod names. Failed to list pods", "Memcached.Namespace", memcached.Namespace, "Memcached.Name", memcached.Name)
        return ctrl.Result{}, err
    }
    podNames := getPodNames(podList.Items)
    log.Info("4. Update the Memcached status with the pod names. Pod list", "podNames", podNames)

    // Update status.Nodes if needed
    if !reflect.DeepEqual(podNames, memcached.Status.Nodes) {
        memcached.Status.Nodes = podNames
        err := r.Status().Update(ctx, memcached)
        if err != nil {
            log.Error(err, "4. Update the Memcached status with the pod names. Failed to update Memcached status")
            return ctrl.Result{}, err
        }
    }
    log.Info("4. Update the Memcached status with the pod names. Update memcached.Status", "memcached.Status.Nodes", memcached.Status.Nodes)

    return ctrl.Result{}, nil
}

...

// 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
}