Commit Graph

13 Commits

Author SHA1 Message Date
Dalton Hubble
937acc4b5a Re-enable Graceful Node Shutdown feature
* Kubelet GracefulNodeShutdown works, but only partially handles
gracefully stopping the Kubelet. The most noticeable drawback
is that Completed Pods are left around
* Use a project like poseidon/scuttle or a similar systemd unit
as a snippet to add drain and/or delete behaviors if desired
* This reverts commit 1786e34f33.

Rel:

* https://www.psdn.io/posts/kubelet-graceful-shutdown/
* https://github.com/poseidon/scuttle
2022-11-02 20:49:01 -07:00
Dalton Hubble
651151805d Update Kubernetes v1.25.2 to v1.25.3
* https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.25.md#v1253
2022-10-13 21:02:39 -07:00
Dalton Hubble
3ee462a24c Update Kubernetes from v1.25.1 to v1.25.2
* https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.25.md#v1252
2022-09-22 08:15:30 -07:00
Dalton Hubble
74d4d56dbd Remove workaround for v1.25.0 ConfigMap rendering issue
* LocalStorageCapacityIsolationFSQuotaMonitoring was reverted back to
alpha in v1.25.1, so we don't need to explicitly disable it anymore

Rel: https://github.com/kubernetes/kubernetes/issues/112081
2022-09-19 09:10:24 -07:00
Dalton Hubble
5abe84b520 Update etcd from v3.5.4 to v3.5.5
* https://github.com/etcd-io/etcd/blob/main/CHANGELOG/CHANGELOG-3.5.md#v355
2022-09-15 09:01:45 -07:00
Dalton Hubble
09751cc0e8 Update Kubernetes from v1.25.0 to v1.25.1
* https://github.com/kubernetes/kubernetes/releases/tag/v1.25.1
2022-09-15 08:23:22 -07:00
Dalton Hubble
1786e34f33 Revert Graceful Node Shutdown feature
* Disable Kubelet Graceful Node Shutdown on worker nodes (enabled in
Kubernetes v1.25.0 https://github.com/poseidon/typhoon/pull/1222)
* Graceful node shutdown shutdown allows 30s for critical pods to
shutdown and 15s for regular pods to shutdown before releasing the
inhibitor lock to allow the host to shutdown
* Unfortunately, both pods and the node are shutdown at the same
time at the end of the 45s period without further configuration
options. As a result, regular pods and the node are shutdown at the
same time. In practice, enabling this feature leaves Error or Completed
pods in kube-apiserver state until manually cleaned up. This feature
is not ready for general use
* Fix issue where Error/Completed pods are accumulating whenever any
node restarts (or auto-updates), visible in kubectl get pods
* This issue wasn't apparent in initial testing and seems to only
affect non-critical pods (due to critical pods being killed earlier)
But its very apparent on our real clusters

Rel: https://github.com/kubernetes/kubernetes/issues/110755
2022-09-10 14:58:44 -07:00
Dalton Hubble
393a38deff Configure Graceful Node Shutdown and lengthen max inhibitor delay
* Configure Kubelet Graceful Node Shutdown to detect system shutdown
events and stop running containers gracefully when possible
* Allow up to 30s for critical pods to gracefully shutdown
* Allow up to 15s for regular pods to gracefully shutdown
* Node will be marked as NotReady promptly, instead of having to
wait for health checks
* Kubelet uses systemd inhibitor locks to delay shutdown for a limited
number of seconds
* Raise the default max inhibitor time from 5s to 45s

Verify systemd inhibitor locks are present:

```
sudo systemd-inhibit --list
WHO     UID USER PID  COMM    WHAT     WHY                                        MODE
kubelet 0   root 4581 kubelet shutdown Kubelet needs time to handle node shutdown delay
```

Tail journal logs and then shutdown a node via systemctl reboot
or via the cloud console to watch container shutdown

Rel:

* https://kubernetes.io/blog/2021/04/21/graceful-node-shutdown-beta/
* https://kubernetes.io/docs/reference/config-api/kubelet-config.v1beta1/
* https://github.com/kubernetes/kubernetes/issues/107043
* https://github.com/coreos/fedora-coreos-tracker/issues/821
* https://www.freedesktop.org/software/systemd/man/systemd-inhibit.html
* https://github.com/kubernetes/kubernetes/blob/release-1.24/pkg/kubelet/nodeshutdown/nodeshutdown_manager_linux.go
* https://github.com/godbus/dbus/blob/master/conn.go
2022-08-28 10:37:33 -07:00
Dalton Hubble
275fc0f9e8 Disable LocalStorageCapacityIsolationFSQuotaMonitoring feature
* Kubernetes v1.25.0 moved the LocalStorageCapacityIsolationFSQuotaMonitoring
feature from alpha to beta, but it breaks Kubelet updating ConfigMaps in
Pods, as shown by conformance tests
* Kubernetes is rolling LocalStorageCapacityIsolationFSQuotaMonitoring back
to alpha so its not enabled by default, but that will require a release
* Disable the feature gate directly as a workaround for now to make
Kubernetes v1.25.0 usable

```
FailedMount: MountVolume.SetUp failed for volume "configmap-volume" : requesting quota on existing directory /var/lib/kubelet/pods/f09fae17-ff16-4a05-aab3-7b897cb5b732/volumes/kubernetes.io~configmap/configmap-volume but different pod 673ad247-abf0-434e-99eb-1c3f57d7fdaa a4568e94-2b2d-438f-a4bd-c9edc814e478
```

Rel:

* https://github.com/kubernetes/kubernetes/pull/112076
* https://github.com/kubernetes/kubernetes/pull/107329
2022-08-27 09:49:35 -07:00
Dalton Hubble
3fb59a3289 Migrate most Kubelet flags to KubeletConfiguration file
* Add a KubeletConfiguration file to replace most Kubelet
flags, to prepare for upcoming changes
* Pass Kubelet the --config flag to specify the location of
the KubeletConfiguration
* Remove flsgs / configuration where it matches the defaults
  * Remove --cgroups-per-qos, defaults to true
  * Remove --container-runtime, defaults to remote
  * Remove enforce-node-allocatable=pods, defaults to pods

Rel:

* https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/
* https://kubernetes.io/docs/reference/config-api/kubelet-config.v1beta1/
2022-08-27 09:28:15 -07:00
Dalton Hubble
a31dbceac6 Update Kubernetes from v1.24.4 to v1.25.0
* https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.25.md
2022-08-25 09:18:14 -07:00
Dalton Hubble
760b4cd5ee Update Kubernetes from v1.24.3 to v1.24.4
* https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.24.md#v1244
2022-08-17 20:09:30 -07:00
Dalton Hubble
4a469513dd Migrate Flatcar Linux from Ignition spec v2.3.0 to v3.3.0
* Requires poseidon v0.11+ and Flatcar Linux 3185.0.0+ (action required)
* Previously, Flatcar Linux configs have been parsed as Container
Linux Configs to Ignition v2.2.0 specs by poseidon/ct
* Flatcar Linux starting in 3185.0.0 now supports Ignition v3.x specs
(which are rendered from Butane Configs, like Fedora CoreOS)
* poseidon/ct v0.11.0 adds support for the flatcar Butane Config
variant so that Flatcar Linux can use Ignition v3.x

Rel:

* [Flatcar Support](https://flatcar-linux.org/docs/latest/provisioning/ignition/specification/#ignition-v3)
* [poseidon/ct support](https://github.com/poseidon/terraform-provider-ct/pull/131)
2022-08-03 08:32:52 -07:00