This extends the Kubelet to create and periodically update leases in a
new kube-node-lease namespace. Based on [KEP-0009](https://github.com/kubernetes/community/blob/master/keps/sig-node/0009-node-heartbeat.md),
these leases can be used as a node health signal, and will allow us to
reduce the load caused by over-frequent node status reporting.
- add NodeLease feature gate
- add kube-node-lease system namespace for node leases
- add Kubelet option for lease duration
- add Kubelet-internal lease controller to create and update lease
- add e2e test for NodeLease feature
- modify node authorizer and node restriction admission controller
to allow Kubelets access to corresponding leases
Automatic merge from submit-queue (batch tested with PRs 66850, 66902, 66779, 66864, 66912). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
add methods to apimachinery to easy unit testing
When unit testing, you often want a selective scheme and codec factory. Rather than writing the vars and the init function and the error handling, you can simply do
`scheme, codecs := testing.SchemeForInstallOrDie(install.Install)`
@kubernetes/sig-api-machinery-misc
@sttts
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 65730, 66615, 66684, 66519, 66510). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubelet: add image-gc low/high validation check
Currently, there is no protection against setting the high watermark <= the low watermark for image GC
This PR adds a validation rule for that.
@smarterclayton
Automatic merge from submit-queue (batch tested with PRs 65187, 65206, 65223, 64752, 65238). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Kubelet watches necessary secrets/configmaps instead of periodic polling
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Validate cgroups-per-qos for Windows
**What this PR does / why we need it**:
cgroups-per-qos and enforce-node-allocatable is not supported on Windows, but kubelet allows it on Windows. And then Pods may stuck in terminating state because of it. Refer #61716.
This PR adds validation for them and make kubelet refusing to start in this case.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#61716
**Special notes for your reviewer**:
**Release note**:
```release-note
Fail fast if cgroups-per-qos is set on Windows
```
This fixes an issue with KubeletConfiguration validation, where the
feature gates set by the new config were not taken into account.
Also fixes a validation issue with dynamic Kubelet config, where flag
precedence was not enforced prior to dynamic config validation in the
controller; this prevented rejection of dynamic configs that don't merge
well with values set via legacy flags.
This makes the Kubelet config key in the ConfigMap an explicit part of
the API, so we can stop using magic key names.
As part of this change, we are retiring ConfigMapRef for ConfigMap.
The API conventions specify that json keys should start with a lowercase
character, and if the key starts with an initialism, all characters in
the initialism should be lowercase. See `tlsCipherSuites` as an example.
API Conventions:
https://github.com/kubernetes/community/blob/master/contributors/devel/api-conventions.md
>All letters in the acronym should have the same case, using the
>appropriate case for the situation. For example, at the beginning
>of a field name, the acronym should be all lowercase, such as "httpGet".
Automatic merge from submit-queue (batch tested with PRs 61962, 58972, 62509, 62606). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubelet: move QOSReserved from experimental to alpha feature gate
Fixes https://github.com/kubernetes/kubernetes/issues/61665
**Release note**:
```release-note
The --experimental-qos-reserve kubelet flags is replaced by the alpha level --qos-reserved flag or QOSReserved field in the kubeletconfig and requires the QOSReserved feature gate to be enabled.
```
/sig node
/assign @derekwaynecarr
/cc @mtaufen
right now if the RotateKubeletServerCertificate feature is enabled,
kubelet will bootstrap server tls. this is undesirable if the deployment
is not or cannot run an approver to handle these certificate signing
requests.
The word 'manifest' technically refers to a container-group specification
that predated the Pod abstraction. We should avoid using this legacy
terminology where possible. Fortunately, the Kubelet's config API will
be beta in 1.10 for the first time, so we still had the chance to make
this change.
I left the flags alone, since they're deprecated anyway.
I changed a few var names in files I touched too, but this PR is the
just the first shot, not the whole campaign
(`git grep -i manifest | wc -l -> 1248`).
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Secure Kubelet's componentconfig defaults while maintaining CLI compatibility
This updates the Kubelet's componentconfig defaults, while applying the legacy defaults to values from options.NewKubeletConfiguration(). This keeps defaults the same for the command line and improves the security of defaults when you load config from a file.
See: https://github.com/kubernetes/kubernetes/issues/53618
See: https://github.com/kubernetes/kubernetes/pull/53833#discussion_r166669931
Also moves EnableServer to KubeletFlags, per @tallclair's comments on #53833.
We should find way of generating documentation for config file defaults, so that people can easily look up what's different from flags.
```release-note
Action required: Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's command line. Be sure to review the default values when migrating to using a config file.
```
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Ignore 0% and 100% eviction thresholds
Primarily, this gives a way to explicitly disable eviction, which is
necessary to use omitempty on EvictionHard.
See: https://github.com/kubernetes/kubernetes/pull/53833#discussion_r166672137
As justification for this approach, neither 0% nor 100% make sense as
eviction thresholds; in the "less-than" case, you can't have less than
0% of a resource and 100% perpetually evicts; in the
"greater-than" case (assuming we ever add a resource with this
semantic), the reasoning is the reverse (not more than 100%, 0%
perpetually evicts).
```release-note
Eviction thresholds set to 0% or 100% are now ignored.
```
Primarily, this gives a way to explicitly disable eviction, which is
necessary to use omitempty on EvictionHard.
See: https://github.com/kubernetes/kubernetes/pull/53833#discussion_r166672137
As justification for this approach, neither 0% nor 100% make sense as
eviction thresholds; in the "less-than" case, you can't have less than
0% of a resource and 100% perpetually evicts; in the
"greater-than" case (assuming we ever add a resource with this
semantic), the reasoning is the reverse (not more than 100%, 0%
perpetually evicts).
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
fix all the typos across the project
**What this PR does / why we need it**:
There are lots of typos across the project. We should avoid small PRs on fixing those annoying typos, which is time-consuming and low efficient.
This PR does fix all the typos across the project currently. And with #59463, typos could be avoided when a new PR gets merged.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
/sig testing
/area test-infra
/sig release
/cc @ixdy
/assign @fejta
**Release note**:
```release-note
None
```
They should both follow the convention of not being a pointer on the
internal type. This required adding a conversion function between
`int64` and `*int64`.
A side effect is this removes a warning in the generated code for the
apps API group.
Automatic merge from submit-queue (batch tested with PRs 57973, 57990). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Set pids limit at pod level
**What this PR does / why we need it**:
Add a new Alpha Feature to set a maximum number of pids per Pod.
This is to allow the use case where cluster administrators wish
to limit the pids consumed per pod (example when running a CI system).
By default, we do not set any maximum limit, If an administrator wants
to enable this, they should enable `SupportPodPidsLimit=true` in the
`--feature-gates=` parameter to kubelet and specify the limit using the
`--pod-max-pids` parameter.
The limit set is the total count of all processes running in all
containers in the pod.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#43783
**Special notes for your reviewer**:
**Release note**:
```release-note
New alpha feature to limit the number of processes running in a pod. Cluster administrators will be able to place limits by using the new kubelet command line parameter --pod-max-pids. Note that since this is a alpha feature they will need to enable the "SupportPodPidsLimit" feature.
```
Add a new Alpha Feature to set a maximum number of pids per Pod.
This is to allow the use case where cluster administrators wish
to limit the pids consumed per pod (example when running a CI system).
By default, we do not set any maximum limit, If an administrator wants
to enable this, they should enable `SupportPodPidsLimit=true` in the
`--feature-gates=` parameter to kubelet and specify the limit using the
`--pod-max-pids` parameter.
The limit set is the total count of all processes running in all
containers in the pod.
