我正在跟进本教程 https://learn.openshift.com/operatorframework/go-operator-podset/创建我的第一个名为 PodSet 的自定义资源，目前处于第 6 步（共 7 步）来测试我的 CR。
这是我的 Operator SDK 控制器 Go 代码：
package controllers
import (
"context"
"reflect"
"github.com/go-logr/logr"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
ctrl "sigs.k8s.io/controller-runtime"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
appv1alpha1 "github.com/redhat/podset-operator/api/v1alpha1"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)
// PodSetReconciler reconciles a PodSet object
type PodSetReconciler struct {
client.Client
Log logr.Logger
Scheme *runtime.Scheme
}
// +kubebuilder:rbac:groups=app.example.com,resources=podsets,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=app.example.com,resources=podsets/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=v1,resources=pods,verbs=get;list;watch;create;update;patch;delete
// Reconcile is the core logic of controller
func (r *PodSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
_ = context.Background()
_ = r.Log.WithValues("podset", req.NamespacedName)
// Fetch the PodSet instance (the parent of the pods)
instance := &appv1alpha1.PodSet{}
err := r.Get(context.Background(), req.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{}
labelz := map[string]string{
"app": podSet.Name, // the metadata.name field from user's CR PodSet YAML file
"version": "v0.1",
}
labelSelector := labels.SelectorFromSet(labelz)
listOpts := &client.ListOptions{Namespace: podSet.Namespace, LabelSelector: labelSelector}
if err = r.List(context.Background(), podList, listOpts); err != nil {
return reconcile.Result{}, err
}
// Count the pods that are pending or running and add them to available array
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,
AvailableReplicas: numAvailable,
}
if !reflect.DeepEqual(podSet.Status, status) {
podSet.Status = status
err = r.Status().Update(context.Background(), podSet)
if err != nil {
r.Log.Error(err, "Failed to update PodSet status")
return reconcile.Result{}, err
}
}
// When the number of pods in the cluster is bigger that what we want, scale down
if numAvailable > podSet.Spec.Replicas {
r.Log.Info("Scaling down pods", "Currently available", numAvailable, "Required replicas", podSet.Spec.Replicas)
diff := numAvailable - podSet.Spec.Replicas
toDeletePods := available[:diff] // Syntax help: https://play.golang.org/p/SHAMCdd12sp
for _, toDeletePod := range toDeletePods {
err = r.Delete(context.Background(), &toDeletePod)
if err != nil {
r.Log.Error(err, "Failed to delete pod", "pod.name", toDeletePod.Name)
return reconcile.Result{}, err
}
}
return reconcile.Result{Requeue: true}, nil
}
// When the number of pods in the cluster is smaller that what we want, scale up
if numAvailable < podSet.Spec.Replicas {
r.Log.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 of the Pod
if err := controllerutil.SetControllerReference(podSet, pod, r.Scheme); err != nil {
return reconcile.Result{}, err
}
err = r.Create(context.Background(), pod)
if err != nil {
r.Log.Error(err, "Failed to create pod", "pod.name", pod.Name)
return reconcile.Result{}, err
}
return reconcile.Result{Requeue: true}, nil
}
return ctrl.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, // the metadata.name field from user's CR PodSet YAML file
"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"},
},
},
},
}
}
// SetupWithManager defines how the controller will watch for resources
func (r *PodSetReconciler) SetupWithManager(mgr ctrl.Manager) error {
return ctrl.NewControllerManagedBy(mgr).
For(&appv1alpha1.PodSet{}).
Owns(&corev1.Pod{}).
Complete(r)
}
当我应用下面的 YAML 文件时，我看到了 Pod 的奇怪行为。他们在最初的几秒钟里很挣扎——其中一些人站起来运行了一段时间，然后很快就进入了终止状态。当我再让它们保持不动几秒钟时，CR 就很好地达到了所需的状态。
apiVersion: app.example.com/v1alpha1
kind: PodSet
metadata:
name: podset-sample
spec:
replicas: 5
我捕获了上面的部署场景这个视频 https://youtu.be/bK5_2uiDuhE. And here https://pastebin.com/raw/md0QYx23我的本地终端运行的完整日志是WATCH_NAMESPACE=podset-operator make run命令（抱歉，我必须使用 Pastebin，因为 SO 不允许我在此处粘贴完整日志，因为它们太长了）。
所以，我的问题是：
- 什么是
Failed to update PodSet status {"error": "Operation cannot be fulfilled on podsets.app.example.com \"podset-sample\": the object has been modified; please apply your changes to the latest version and try again"}实际上意味着什么？
- 为什么会发生这样的事？
- 我该怎么做才能消除这些错误？
