* 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
* 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
* Changes to worker launch configurations start an autoscaling group instance
refresh to replace instances
* Instance refresh creates surge instances, waits for a warm-up period, then
deletes old instances
* Changing worker_type, disk_*, worker_price, worker_target_groups, or Butane
worker_snippets on existing worker nodes will replace instances
* New AMIs or changing `os_stream` will be ignored, to allow Fedora CoreOS or
Flatcar Linux to keep themselves updated
* Previously, new launch configurations were made in the same way, but not
applied to instances unless manually replaced
* Rename launch configuration to use a name_prefix named after the
cluster and worker to improve identifiability
* Shorten AWS autoscaling group name to not include the launch config
id. Years ago this used to be needed to update the ASG but the AWS
provider detects changes to the launch configuration just fine
* 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)
* Add `arch` variable to Flatcar Linux AWS `kubernetes` and
`workers` modules. Accept `amd64` (default) or `arm64` to support
native arm64/aarch64 clusters or mixed/hybrid clusters with arm64
workers
* Requires `flannel` or `cilium` CNI
Similar to https://github.com/poseidon/typhoon/pull/875
* Both Flatcar Linux and Fedora CoreOS use systemd-resolved,
but they setup /etc/resolv.conf symlinks differently
* Prefer using /run/systemd/resolve/resolv.conf directly, which
also updates to reflect runtime changes (e.g. resolvectl)
* Update `null` provider to allow use of v3.1.x releases,
instead of being stuck on v2.1.2
* Update min versions in terraform-render-boostrap
https://github.com/poseidon/terraform-render-bootstrap/pull/287
* Document the recommended versions of Terraform cloud providers
* Remove `/sys/fs/cgroup/systemd` mount since Flatcar Linux
uses cgroups v2
* Flatcar Linux's `docker` switched from the `cgroupfs` to
`systemd` driver without notice
* Add `node_taints` variable to worker modules to set custom
initial node taints on cloud platforms that support auto-scaling
worker pools of heterogeneous nodes (i.e. AWS, Azure, GCP)
* Worker pools could use custom `node_labels` to allowed workloads
to select among differentiated nodes, while custom `node_taints`
allows a worker pool's nodes to be tainted as special to prevent
scheduling, except by workloads that explicitly tolerate the
taint
* Expose `daemonset_tolerations` in AWS, Azure, and GCP kubernetes
cluster modules, to determine whether `kube-system` components
should tolerate the custom taint (advanced use covered in docs)
Rel: #550, #663Closes#429
* Set the Kubelet `--provider-id` on AWS based on metadata from
Fedora CoreOS afterburn or Flatcar Linux coreos-metadata
* Based on https://github.com/poseidon/typhoon/pull/951
* Flatcar Linux has not published an Edge channel image since
April 2020 and recently removed mention of the channel from
their documentation https://github.com/kinvolk/Flatcar/pull/345
* Users of Flatcar Linux Edge should move to the stable, beta, or
alpha channel, barring any alternate advice from upstream Flatcar
Linux
Dalton Hubble
Anshul Sirur