Bug 1882140

Summary:	No description for spec.kubeletConfig
Product:	OpenShift Container Platform	Reporter:	Jason Boxman <jboxman>
Component:	Node	Assignee:	Harshal Patil <harpatil>
Node sub component:	Kubelet	QA Contact:	MinLi <minmli>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	low
Priority:	low	CC:	aos-bugs, harpatil, jerzhang, mkrejci
Version:	4.6	Keywords:	Reopened
Target Milestone:	---
Target Release:	4.7.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-02-24 15:19:20 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jason Boxman 2020-09-23 21:42:42 UTC

Description of problem:

I'm unfamiliar with the MCO, and when looking at the spec, there is no description for what the `spec.kubeletConfig` field expects. (`machineConfigPoolSelector` does have a description, for example.)

How reproducible:

Always.

Steps to Reproduce:

`oc explain KubeletConfig --recursive=true`

Comment 1 Yu Qi Zhang 2020-12-08 21:02:23 UTC

Hi, sorry for the delay in response.

The kubeletConfig field by design comes from upstream, e.g. https://github.com/kubernetes/kubernetes/blob/release-1.19/staging/src/k8s.io/kubelet/config/v1beta1/types.go#L75 once we rebase on 1.19.

As for description, I agree that our CRD definition isn't very clear, but there should be some documentation around how to use this. Moving over to the node team to see whether they feel there is a need to add a reference, etc. If not feel free to close.

Comment 2 Harshal Patil 2021-01-05 02:51:34 UTC

https://github.com/openshift/machine-config-operator/blob/master/docs/KubeletConfigDesign.md describes the usage of KubeletConfig. 

As mentioned in https://bugzilla.redhat.com/show_bug.cgi?id=1882140#c1, the kubeletConfig field by design comes from upstream. So you will have to refer to the upstream 'types.go' to see what values you want to put in the KubeletConfig. 

e.g. if you want to bump up systemReserve to 2G, you will have to declare the KubeleConfig in the following way,


kind: KubeletConfig
metadata:
  name: worker-kubeconfig-fix
spec:
  machineConfigPoolSelector:
    matchLabels:
      custom-kubelet: small-pods 
  kubeletConfig:
    systemReserved:
      memory: 2000Mi

Comment 3 Jason Boxman 2021-01-05 15:04:30 UTC

But this presents an _empty_ description field to the user. So it isn't clear how a user knows what you stated is what is required, particularly someone new to OCP and k8s.

So while this isn't an implementation bug, it is a bad user experience.

Because this description originates with MCO, maybe someone from MCO can include a description for this field in the CRD?

Even: "A kubelet config object" would be an improvement. Otherwise it renders as an empty field as shown here:

https://docs.openshift.com/container-platform/4.6/rest_api/machine_apis/kubeletconfig-machineconfiguration-openshift-io-v1.html

Thanks.

Comment 5 MinLi 2021-01-18 08:05:57 UTC

verified on version : 4.7.0-0.nightly-2021-01-17-211555

$ oc explain KubeletConfig.spec.kubeletConfig --recursive=true
KIND:     KubeletConfig
VERSION:  machineconfiguration.openshift.io/v1

DESCRIPTION:
     The fields of the kubelet configuration are defined in kubernetes upstream.
     Please refer to the types defined in the version/commit used by OpenShift
     of the upstream kubernetes.

Comment 8 errata-xmlrpc 2021-02-24 15:19:20 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: OpenShift Container Platform 4.7.0 security, bug fix, and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2020:5633