### SIG-cluster-lifecycle

In 1.12, SIG Cluster lifecycle has focused on improving the user experience in kubeadm, by fixing a number of bugs and adding some new important features.

Here is a list of some of the changes that have been made to kubeadm:

- Kubeadm internal config has been promoted to `v1alpha3`:
  - `v1alpha1` has been removed.

  - [Changelog since v1.20.5](#changelog-since-v1205)
  - [Important Security Information](#important-security-information-1)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-9)
    - [API Change](#api-change-2)
    - [Feature](#feature-5)
    - [Bug or Regression](#bug-or-regression-9)

- In some cases, a Flex volume resize may leave a PVC with erroneous Resizing condition even after volume has been successfully expanded. Users may choose to delete the condition, but it is not required. ([#71470](https://github.com/kubernetes/kubernetes/issues/71470))

* kubeadm: Fixes a small bug where `--config` and `--skip-*` flags couldn't be passed at the same time in validation. ([#49498](https://github.com/kubernetes/kubernetes/pull/49498), [@luxas](https://github.com/luxas))

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334),...

  - [Changelog since v1.18.17](#changelog-since-v11817)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-2)
    - [API Change](#api-change-1)
    - [Feature](#feature)
    - [Bug or Regression](#bug-or-regression-2)

- Using `--log-file` is known to be problematic in 1.15. This presents as things being logged multiple times to the same file. The behaviour and details of this issue, as well as some preliminary attempts at fixing it are documented [here](https://github.com/kubernetes/kubernetes/issues/78734#issuecomment-501372131)

- `oc describe quota` used has the same unit format as hard ([#102177](https://github.com/kubernetes/kubernetes/pull/102177),...

* The validated docker versions are the same as for v1.10: 1.11.2 to 1.13.1 and 17.03.x (ref)
* The Go version is go1.10.2, as compared to go1.9.3 in v1.10. ([#63412](https://github.com/kubernetes/kubernetes/pull/63412))
* The minimum supported go is the same as for v1.10: go1.9.1. ([#55301](https://github.com/kubernetes/kubernetes/pull/55301))

* Azure cloudprovider: Reduce the polling delay for all azure clients to 5 seconds. This should speed up some operations at the cost of some additional quota. ([#43699](https://github.com/kubernetes/kubernetes/pull/43699), [@colemickens](https://github.com/colemickens))