Implement shutdown manager in kubelet

Implements KEP 2000, Graceful Node Shutdown:
https://github.com/kubernetes/enhancements/tree/master/keps/sig-node/2000-graceful-node-shutdown

* Add new FeatureGate `GracefulNodeShutdown` to control
enabling/disabling the feature
* Add two new KubeletConfiguration options
  * `ShutdownGracePeriod` and `ShutdownGracePeriodCriticalPods`
* Add new package, `nodeshutdown` that implements the Node shutdown
manager
  * The node shutdown manager uses the systemd inhibit package, to
  create an system inhibitor, monitor for node shutdown events, and
  gracefully terminate pods upon a node shutdown.
This commit is contained in:
David Porter
2020-11-02 23:18:36 +00:00
parent 2343689ce7
commit 16f71c6d47
20 changed files with 896 additions and 124 deletions

View File

@@ -140,6 +140,21 @@ func ValidateKubeletConfiguration(kc *kubeletconfig.KubeletConfiguration) error
allErrors = append(allErrors, fmt.Errorf("invalid configuration: topologyManagerScope non-allowable value: %v", kc.TopologyManagerScope))
}
if localFeatureGate.Enabled(features.GracefulNodeShutdown) {
if kc.ShutdownGracePeriod.Duration < 0 || kc.ShutdownGracePeriodCriticalPods.Duration < 0 || kc.ShutdownGracePeriodCriticalPods.Duration > kc.ShutdownGracePeriod.Duration {
allErrors = append(allErrors, fmt.Errorf("invalid configuration: ShutdownGracePeriod %v must be >= 0, ShutdownGracePeriodCriticalPods %v must be >= 0, and ShutdownGracePeriodCriticalPods %v must be <= ShutdownGracePeriod %v", kc.ShutdownGracePeriod, kc.ShutdownGracePeriodCriticalPods, kc.ShutdownGracePeriodCriticalPods, kc.ShutdownGracePeriod))
}
if kc.ShutdownGracePeriod.Duration > 0 && kc.ShutdownGracePeriod.Duration < time.Duration(time.Second) {
allErrors = append(allErrors, fmt.Errorf("invalid configuration: ShutdownGracePeriod %v must be either zero or otherwise >= 1 sec", kc.ShutdownGracePeriod))
}
if kc.ShutdownGracePeriodCriticalPods.Duration > 0 && kc.ShutdownGracePeriodCriticalPods.Duration < time.Duration(time.Second) {
allErrors = append(allErrors, fmt.Errorf("invalid configuration: ShutdownGracePeriodCriticalPods %v must be either zero or otherwise >= 1 sec", kc.ShutdownGracePeriodCriticalPods))
}
}
if (kc.ShutdownGracePeriod.Duration > 0 || kc.ShutdownGracePeriodCriticalPods.Duration > 0) && !localFeatureGate.Enabled(features.GracefulNodeShutdown) {
allErrors = append(allErrors, fmt.Errorf("invalid configuration: Specifying ShutdownGracePeriod or ShutdownGracePeriodCriticalPods requires feature gate GracefulNodeShutdown"))
}
for _, val := range kc.EnforceNodeAllocatable {
switch val {
case kubetypes.NodeAllocatableEnforcementKey: