constellation/operators/constellation-node-operator/controllers/pendingnode_controller.go
2023-01-05 14:52:09 +01:00

256 lines
9.2 KiB
Go

/*
Copyright (c) Edgeless Systems GmbH
SPDX-License-Identifier: AGPL-3.0-only
*/
package controllers
import (
"context"
"time"
node "github.com/edgelesssys/constellation/v2/operators/constellation-node-operator/v2/internal/node"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/types"
"k8s.io/client-go/util/retry"
"k8s.io/utils/clock"
ctrl "sigs.k8s.io/controller-runtime"
"sigs.k8s.io/controller-runtime/pkg/builder"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/event"
"sigs.k8s.io/controller-runtime/pkg/handler"
"sigs.k8s.io/controller-runtime/pkg/log"
"sigs.k8s.io/controller-runtime/pkg/predicate"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
"sigs.k8s.io/controller-runtime/pkg/source"
updatev1alpha1 "github.com/edgelesssys/constellation/v2/operators/constellation-node-operator/v2/api/v1alpha1"
)
const (
nodeNameKey = ".spec.nodeName"
defaultCheckInterval = 30 * time.Second
)
// PendingNodeReconciler reconciles a PendingNode object.
type PendingNodeReconciler struct {
nodeStateGetter
client.Client
Scheme *runtime.Scheme
clock.Clock
}
// NewPendingNodeReconciler creates a new PendingNodeReconciler.
func NewPendingNodeReconciler(nodeStateGetter nodeStateGetter, client client.Client, scheme *runtime.Scheme) *PendingNodeReconciler {
return &PendingNodeReconciler{
nodeStateGetter: nodeStateGetter,
Client: client,
Scheme: scheme,
Clock: clock.RealClock{},
}
}
//+kubebuilder:rbac:groups=update.edgeless.systems,resources=pendingnodes,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=update.edgeless.systems,resources=pendingnodes/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=update.edgeless.systems,resources=pendingnodes/finalizers,verbs=update
//+kubebuilder:rbac:groups="",resources=nodes,verbs=get;list;watch
//+kubebuilder:rbac:groups="",resources=nodes/status,verbs=get
// Reconcile observes the state of a pending node that is either trying to join the cluster or is leaving the cluster (waiting to be destroyed).
// If the node is trying to join the cluster and fails to join within the deadline referenced in the PendingNode spec, the node is deleted.
func (r *PendingNodeReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
logr := log.FromContext(ctx)
var pendingNode updatev1alpha1.PendingNode
if err := r.Get(ctx, req.NamespacedName, &pendingNode); err != nil {
if !errors.IsNotFound(err) {
logr.Error(err, "Unable to fetch PendingNode")
}
return ctrl.Result{}, client.IgnoreNotFound(err)
}
nodeState, err := r.GetNodeState(ctx, pendingNode.Spec.ProviderID)
if err != nil {
logr.Error(err, "Unable to get node state")
return ctrl.Result{Requeue: true}, err
}
done, err := r.reachedGoal(ctx, pendingNode, nodeState)
if err != nil {
logr.Error(err, "Unable to check if node reached goal")
return ctrl.Result{}, err
}
status := updatev1alpha1.PendingNodeStatus{
CSPNodeState: nodeState,
ReachedGoal: done,
}
if err := r.tryUpdateStatus(ctx, req.NamespacedName, &pendingNode, status); err != nil {
return ctrl.Result{}, client.IgnoreNotFound(err)
}
if done {
logr.Info("Reached goal", "pendingNodeGoal", pendingNode.Spec.Goal, "cspNodeState", nodeState)
if pendingNode.Spec.Goal == updatev1alpha1.NodeGoalLeave {
// delete self after pending node has been terminated successfully
if err := r.deletePendingNode(ctx, req.NamespacedName); err != nil {
return ctrl.Result{}, err
}
logr.Info("Deleted pending node resource for terminated node", "pendingNode", req.Name)
}
return ctrl.Result{}, nil
}
// check if the deadline has been reached
// requeue if not
if pendingNode.Spec.Deadline == nil || r.Now().Before(pendingNode.Spec.Deadline.Time) {
var requeueAfter time.Duration
if pendingNode.Spec.Deadline == nil {
requeueAfter = defaultCheckInterval
} else {
requeueAfter = pendingNode.Spec.Deadline.Time.Sub(r.Now())
}
return ctrl.Result{
RequeueAfter: requeueAfter,
}, nil
}
// deadline has been reached
switch pendingNode.Spec.Goal {
case updatev1alpha1.NodeGoalJoin:
logr.Info("Node did not get ready in time or failed to join", "pendingNode", pendingNode.Spec.NodeName, "pendingNodeGoal", pendingNode.Spec.Goal, "cspNodeState", nodeState)
if err := r.DeleteNode(ctx, pendingNode.Spec.ProviderID); err != nil {
logr.Error(err, "Unable to delete node")
return ctrl.Result{}, err
}
pendingNode.Spec.Goal = updatev1alpha1.NodeGoalLeave
pendingNode.Spec.Deadline = nil
if err := r.Update(ctx, &pendingNode); err != nil {
logr.Error(err, "Unable to update PendingNode")
return ctrl.Result{}, err
}
return ctrl.Result{Requeue: true}, nil
case updatev1alpha1.NodeGoalLeave:
logr.Info("Node was not terminated on time", "pendingNodeGoal", pendingNode.Spec.Goal, "cspNodeState", nodeState)
// TODO: decide if other actions should be taken here (e.g. send another request to delete node)
return ctrl.Result{RequeueAfter: defaultCheckInterval}, nil
}
return ctrl.Result{}, nil
}
// SetupWithManager sets up the controller with the Manager.
func (r *PendingNodeReconciler) SetupWithManager(mgr ctrl.Manager) error {
// index pending nodes by nodename.
if err := mgr.GetFieldIndexer().IndexField(context.Background(), &updatev1alpha1.PendingNode{}, nodeNameKey, func(rawObj client.Object) []string {
pendingNode := rawObj.(*updatev1alpha1.PendingNode)
return []string{pendingNode.Spec.NodeName}
}); err != nil {
return err
}
return ctrl.NewControllerManagedBy(mgr).
For(&updatev1alpha1.PendingNode{}).
Watches(
&source.Kind{Type: &corev1.Node{}},
handler.EnqueueRequestsFromMapFunc(r.findObjectsForNode),
builder.WithPredicates(nodeStateChangePredicate()),
).
Complete(r)
}
// nodeStateChangePredicate filters events on Node resources to those that indicate
// joining, leaving, node becoming ready or node receiving a provider id.
func nodeStateChangePredicate() predicate.Predicate {
return predicate.Funcs{
CreateFunc: func(e event.CreateEvent) bool {
return true
},
UpdateFunc: func(e event.UpdateEvent) bool {
oldNode, ok := e.ObjectOld.(*corev1.Node)
if !ok {
return false
}
newNode, ok := e.ObjectNew.(*corev1.Node)
if !ok {
return false
}
becameReady := !node.Ready(oldNode) && node.Ready(newNode)
receivedProviderID := len(oldNode.Spec.ProviderID) == 0 && len(newNode.Spec.ProviderID) != 0
return becameReady || receivedProviderID
},
DeleteFunc: func(e event.DeleteEvent) bool {
return true
},
GenericFunc: func(e event.GenericEvent) bool {
return false
},
}
}
// findObjectsForNode requests reconciliation for PendingNode whenever the corresponding Node state changes.
func (r *PendingNodeReconciler) findObjectsForNode(rawNode client.Object) []reconcile.Request {
var pendingNodesList updatev1alpha1.PendingNodeList
err := r.List(context.Background(), &pendingNodesList, client.MatchingFields{nodeNameKey: rawNode.GetName()})
if err != nil {
return []reconcile.Request{}
}
requests := make([]reconcile.Request, len(pendingNodesList.Items))
for i, item := range pendingNodesList.Items {
requests[i] = reconcile.Request{
NamespacedName: types.NamespacedName{
Name: item.GetName(),
},
}
}
return requests
}
// reachedGoal checks if a pending node has reached its goal (joining or leaving the cluster).
// - joining node: CSP reports the node instance as running and node has joined kubernetes cluster.
// - leaving node: CSP reports node instance as terminated.
func (r *PendingNodeReconciler) reachedGoal(ctx context.Context, pendingNode updatev1alpha1.PendingNode, nodeState updatev1alpha1.CSPNodeState) (bool, error) {
if pendingNode.Spec.Goal == updatev1alpha1.NodeGoalJoin {
if err := r.Get(ctx, types.NamespacedName{Name: pendingNode.Spec.NodeName}, &corev1.Node{}); err != nil {
return false, client.IgnoreNotFound(err)
}
return nodeState == updatev1alpha1.NodeStateReady, nil
}
return nodeState == updatev1alpha1.NodeStateTerminated, nil
}
// deletePendingNode deletes a PendingNode resource.
func (r *PendingNodeReconciler) deletePendingNode(ctx context.Context, name types.NamespacedName) error {
return retry.RetryOnConflict(retry.DefaultRetry, func() error {
var pendingNode updatev1alpha1.PendingNode
if err := r.Get(ctx, name, &pendingNode); err != nil {
return err
}
return r.Delete(ctx, &pendingNode)
})
}
// tryUpdateStatus attempts to update the PendingNode status field in a retry loop.
func (r *PendingNodeReconciler) tryUpdateStatus(ctx context.Context, name types.NamespacedName, pendingNode *updatev1alpha1.PendingNode, status updatev1alpha1.PendingNodeStatus) error {
return retry.RetryOnConflict(retry.DefaultRetry, func() error {
if err := r.Get(ctx, name, pendingNode); err != nil {
return err
}
pendingNode.Status = *status.DeepCopy()
if err := r.Status().Update(ctx, pendingNode); err != nil {
return err
}
return nil
})
}
type nodeStateGetter interface {
// GetNodeState retrieves the state of a pending node from a CSP.
GetNodeState(ctx context.Context, providerID string) (updatev1alpha1.CSPNodeState, error)
// DeleteNode starts the termination of the node at the CSP.
DeleteNode(ctx context.Context, providerID string) error
}