Files
virtual-kubelet/node/pod.go
Sargun Dhillon 4202b03cda Remove sync provider support
This removes the legacy sync provider interface. All new providers
are expected to implement the async NotifyPods interface.

The legacy sync provider interface creates complexities around
how the deletion flow works, and the mixed sync and async APIs
block us from evolving functionality.

This collapses in the NotifyPods interface into the PodLifecycleHandler
interface.
2019-10-02 09:28:09 -07:00

279 lines
9.2 KiB
Go

// Copyright © 2017 The virtual-kubelet authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package node
import (
"context"
"github.com/google/go-cmp/cmp"
pkgerrors "github.com/pkg/errors"
"github.com/virtual-kubelet/virtual-kubelet/errdefs"
"github.com/virtual-kubelet/virtual-kubelet/log"
"github.com/virtual-kubelet/virtual-kubelet/trace"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
)
const (
podStatusReasonProviderFailed = "ProviderFailed"
)
func addPodAttributes(ctx context.Context, span trace.Span, pod *corev1.Pod) context.Context {
return span.WithFields(ctx, log.Fields{
"uid": string(pod.GetUID()),
"namespace": pod.GetNamespace(),
"name": pod.GetName(),
"phase": string(pod.Status.Phase),
"reason": pod.Status.Reason,
})
}
func (pc *PodController) createOrUpdatePod(ctx context.Context, pod *corev1.Pod) error {
ctx, span := trace.StartSpan(ctx, "createOrUpdatePod")
defer span.End()
addPodAttributes(ctx, span, pod)
ctx = span.WithFields(ctx, log.Fields{
"pod": pod.GetName(),
"namespace": pod.GetNamespace(),
})
// We do this so we don't mutate the pod from the informer cache
pod = pod.DeepCopy()
if err := populateEnvironmentVariables(ctx, pod, pc.resourceManager, pc.recorder); err != nil {
span.SetStatus(err)
return err
}
// We have to use a different pod that we pass to the provider than the one that gets used in handleProviderError
// because the provider may manipulate the pod in a separate goroutine while we were doing work
podForProvider := pod.DeepCopy()
// Check if the pod is already known by the provider.
// NOTE: Some providers return a non-nil error in their GetPod implementation when the pod is not found while some other don't.
// Hence, we ignore the error and just act upon the pod if it is non-nil (meaning that the provider still knows about the pod).
if podFromProvider, _ := pc.provider.GetPod(ctx, pod.Namespace, pod.Name); podFromProvider != nil {
if !podsEqual(podFromProvider, podForProvider) {
log.G(ctx).Debugf("Pod %s exists, updating pod in provider", podFromProvider.Name)
if origErr := pc.provider.UpdatePod(ctx, podForProvider); origErr != nil {
pc.handleProviderError(ctx, span, origErr, pod)
return origErr
}
log.G(ctx).Info("Updated pod in provider")
}
} else {
if origErr := pc.provider.CreatePod(ctx, podForProvider); origErr != nil {
pc.handleProviderError(ctx, span, origErr, pod)
return origErr
}
log.G(ctx).Info("Created pod in provider")
}
return nil
}
// podsEqual checks if two pods are equal according to the fields we know that are allowed
// to be modified after startup time.
func podsEqual(pod1, pod2 *corev1.Pod) bool {
// Pod Update Only Permits update of:
// - `spec.containers[*].image`
// - `spec.initContainers[*].image`
// - `spec.activeDeadlineSeconds`
// - `spec.tolerations` (only additions to existing tolerations)
// - `objectmeta.labels`
// - `objectmeta.annotations`
// compare the values of the pods to see if the values actually changed
return cmp.Equal(pod1.Spec.Containers, pod2.Spec.Containers) &&
cmp.Equal(pod1.Spec.InitContainers, pod2.Spec.InitContainers) &&
cmp.Equal(pod1.Spec.ActiveDeadlineSeconds, pod2.Spec.ActiveDeadlineSeconds) &&
cmp.Equal(pod1.Spec.Tolerations, pod2.Spec.Tolerations) &&
cmp.Equal(pod1.ObjectMeta.Labels, pod2.Labels) &&
cmp.Equal(pod1.ObjectMeta.Annotations, pod2.Annotations)
}
func (pc *PodController) handleProviderError(ctx context.Context, span trace.Span, origErr error, pod *corev1.Pod) {
podPhase := corev1.PodPending
if pod.Spec.RestartPolicy == corev1.RestartPolicyNever {
podPhase = corev1.PodFailed
}
pod.ResourceVersion = "" // Blank out resource version to prevent object has been modified error
pod.Status.Phase = podPhase
pod.Status.Reason = podStatusReasonProviderFailed
pod.Status.Message = origErr.Error()
logger := log.G(ctx).WithFields(log.Fields{
"podPhase": podPhase,
"reason": pod.Status.Reason,
})
_, err := pc.client.Pods(pod.Namespace).UpdateStatus(pod)
if err != nil {
logger.WithError(err).Warn("Failed to update pod status")
} else {
logger.Info("Updated k8s pod status")
}
span.SetStatus(origErr)
}
func (pc *PodController) deletePod(ctx context.Context, namespace, name string) error {
ctx, span := trace.StartSpan(ctx, "deletePod")
defer span.End()
pod, err := pc.provider.GetPod(ctx, namespace, name)
if err != nil {
if errdefs.IsNotFound(err) {
// The provider is not aware of the pod, but we must still delete the Kubernetes API resource.
return pc.forceDeletePodResource(ctx, namespace, name)
}
return err
}
// NOTE: Some providers return a non-nil error in their GetPod implementation when the pod is not found while some other don't.
if pod == nil {
// The provider is not aware of the pod, but we must still delete the Kubernetes API resource.
return pc.forceDeletePodResource(ctx, namespace, name)
}
ctx = addPodAttributes(ctx, span, pod)
var delErr error
if delErr = pc.provider.DeletePod(ctx, pod.DeepCopy()); delErr != nil && !errdefs.IsNotFound(delErr) {
span.SetStatus(delErr)
return delErr
}
log.G(ctx).Debug("Deleted pod from provider")
if err := pc.forceDeletePodResource(ctx, namespace, name); err != nil {
span.SetStatus(err)
return err
}
log.G(ctx).Info("Deleted pod from Kubernetes")
return nil
}
func (pc *PodController) forceDeletePodResource(ctx context.Context, namespace, name string) error {
ctx, span := trace.StartSpan(ctx, "forceDeletePodResource")
defer span.End()
ctx = span.WithFields(ctx, log.Fields{
"namespace": namespace,
"name": name,
})
var grace int64
if err := pc.client.Pods(namespace).Delete(name, &metav1.DeleteOptions{GracePeriodSeconds: &grace}); err != nil {
if errors.IsNotFound(err) {
log.G(ctx).Debug("Pod does not exist in Kubernetes, nothing to delete")
return nil
}
span.SetStatus(err)
return pkgerrors.Wrap(err, "Failed to delete Kubernetes pod")
}
return nil
}
func shouldSkipPodStatusUpdate(pod *corev1.Pod) bool {
return pod.Status.Phase == corev1.PodSucceeded ||
pod.Status.Phase == corev1.PodFailed ||
pod.Status.Reason == podStatusReasonProviderFailed
}
func (pc *PodController) updatePodStatus(ctx context.Context, podFromKubernetes *corev1.Pod, key string) error {
if shouldSkipPodStatusUpdate(podFromKubernetes) {
return nil
}
ctx, span := trace.StartSpan(ctx, "updatePodStatus")
defer span.End()
ctx = addPodAttributes(ctx, span, podFromKubernetes)
obj, ok := pc.knownPods.Load(key)
if !ok {
// This means there was a race and the pod has been deleted from K8s
return nil
}
kPod := obj.(*knownPod)
kPod.Lock()
podFromProvider := kPod.lastPodStatusReceivedFromProvider
kPod.Unlock()
if _, err := pc.client.Pods(podFromKubernetes.Namespace).UpdateStatus(podFromProvider); err != nil {
span.SetStatus(err)
return pkgerrors.Wrap(err, "error while updating pod status in kubernetes")
}
log.G(ctx).WithFields(log.Fields{
"new phase": string(podFromProvider.Status.Phase),
"new reason": podFromProvider.Status.Reason,
"old phase": string(podFromKubernetes.Status.Phase),
"old reason": podFromKubernetes.Status.Reason,
}).Debug("Updated pod status in kubernetes")
return nil
}
// enqueuePodStatusUpdate updates our pod status map, and marks the pod as dirty in the workqueue. The pod must be DeepCopy'd
// prior to enqueuePodStatusUpdate.
func (pc *PodController) enqueuePodStatusUpdate(ctx context.Context, q workqueue.RateLimitingInterface, pod *corev1.Pod) {
if key, err := cache.MetaNamespaceKeyFunc(pod); err != nil {
log.G(ctx).WithError(err).WithField("method", "enqueuePodStatusUpdate").Error("Error getting pod meta namespace key")
} else {
if obj, ok := pc.knownPods.Load(key); ok {
kpod := obj.(*knownPod)
kpod.Lock()
kpod.lastPodStatusReceivedFromProvider = pod
kpod.Unlock()
q.AddRateLimited(key)
}
}
}
func (pc *PodController) podStatusHandler(ctx context.Context, key string) (retErr error) {
ctx, span := trace.StartSpan(ctx, "podStatusHandler")
defer span.End()
ctx = span.WithField(ctx, "key", key)
log.G(ctx).Debug("processing pod status update")
defer func() {
span.SetStatus(retErr)
if retErr != nil {
log.G(ctx).WithError(retErr).Error("Error processing pod status update")
}
}()
namespace, name, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return pkgerrors.Wrap(err, "error splitting cache key")
}
pod, err := pc.podsLister.Pods(namespace).Get(name)
if err != nil {
if errors.IsNotFound(err) {
log.G(ctx).WithError(err).Debug("Skipping pod status update for pod missing in Kubernetes")
return nil
}
return pkgerrors.Wrap(err, "error looking up pod")
}
return pc.updatePodStatus(ctx, pod, key)
}