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.
```
- Changes the following KubeletConfiguration fields from `string` to
`map[string]string`:
- `EvictionHard`
- `EvictionSoft`
- `EvictionSoftGracePeriod`
- `EvictionMinimumReclaim`
- Adds flag parsing shims to maintain Kubelet's public flags API, while
enabling structured input in the file API.
- Also removes `kubeletconfig.ConfigurationMap`, which was an ad-hoc flag
parsing shim living in the kubeletconfig API group, and replaces it
with the `MapStringString` shim introduced in this PR. Flag parsing
shims belong in a common place, not in the kubeletconfig API.
I manually audited these to ensure that this wouldn't cause errors
parsing the command line for syntax that would have previously been
error free (`kubeletconfig.ConfigurationMap` was unique in that it
allowed keys to be provided on the CLI without values. I believe this was
done in `flags.ConfigurationMap` to facilitate the `--node-labels` flag,
which rightfully accepts value-free keys, and that this shim was then
just copied to `kubeletconfig`). Fortunately, the affected fields
(`ExperimentalQOSReserved`, `SystemReserved`, and `KubeReserved`) expect
non-empty strings in the values of the map, and as a result passing the
empty string is already an error. Thus requiring keys shouldn't break
anyone's scripts.
- Updates code and tests accordingly.
Regarding eviction operators, directionality is already implicit in the
signal type (for a given signal, the decision to evict will be made when
crossing the threshold from either above or below, never both). There is
no need to expose an operator, such as `<`, in the API. By changing
`EvictionHard` and `EvictionSoft` to `map[string]string`, this PR
simplifies the experience of working with these fields via the
`KubeletConfiguration` type. Again, flags stay the same.
Other things:
- There is another flag parsing shim, `flags.ConfigurationMap`, from the
shared flag utility. The `NodeLabels` field still uses
`flags.ConfigurationMap`. This PR moves the allocation of the
`map[string]string` for the `NodeLabels` field from
`AddKubeletConfigFlags` to the defaulter for the external
`KubeletConfiguration` type. Flags are layered on top of an internal
object that has undergone conversion from a defaulted external object,
which means that previously the mere registration of flags would have
overwritten any previously-defined defaults for `NodeLabels` (fortunately
there were none).
Revert "Merge pull request #51857 from kubernetes/revert-51307-kc-type-refactor"
This reverts commit 9d27d92420, reversing
changes made to 2e69d4e625.
See original: #51307
We punted this from 1.8 so it could go through an API review. The point
of this PR is that we are trying to stabilize the kubeletconfig API so
that we can move it out of alpha, and unblock features like Dynamic
Kubelet Config, Kubelet loading its initial config from a file instead
of flags, kubeadm and other install tools having a versioned API to rely
on, etc.
We shouldn't rev the version without both removing all the deprecated
junk from the KubeletConfiguration struct, and without (at least
temporarily) removing all of the fields that have "Experimental" in
their names. It wouldn't make sense to lock in to deprecated fields.
"Experimental" fields can be audited on a 1-by-1 basis after this PR,
and if found to be stable (or sufficiently alpha-gated), can be restored
to the KubeletConfiguration without the "Experimental" prefix.
Command line flag API remains the same. This allows ComponentConfig
structures (e.g. KubeletConfiguration) to express the map structure
behind feature gates in a natural way when written as JSON or YAML.
For example:
KubeletConfiguration Before:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates: "DynamicKubeletConfig=true,Accelerators=true"
```
KubeletConfiguration After:
```
apiVersion: kubeletconfig/v1alpha1
kind: KubeletConfiguration
featureGates:
DynamicKubeletConfig: true
Accelerators: true
```
As we work towards providing a stable (v1) kubeletconfig API,
we cannot afford to have deprecated or "experimental" (alpha) fields
living in the KubeletConfiguration struct. This removes all existing
experimental or deprecated fields, and places them in KubeletFlags
instead.
I'm going to send another PR after this one that organizes the remaining
fields into substructures for readability. Then, we should try to move
to v1 ASAP.
It makes far more sense to focus on a clean API in kubeletconfig v2,
than to try and further clean up the existing "API" that everyone
already depends on.
The subfeature was a cool idea, but in the end it is very complex to
separate Kubelet restarts into crash-loops caused by config vs.
crash-loops caused by other phenomena, like admin-triggered node restarts,
kernel panics, and and process babysitter behavior. Dynamic kubelet config
will be better off without the potential for false positives here.
Removing this subfeature also simplifies dynamic configuration by
reducing persistent state:
- we no longer need to track bad config in a file
- we no longer need to track kubelet startups in a file
