Bug 1794376 - Remove feature gate IPv6DualStack from default since doesn't work
Summary: Remove feature gate IPv6DualStack from default since doesn't work
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: kube-apiserver
Version: 4.4
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
: 4.4.0
Assignee: Clayton Coleman
QA Contact: Ke Wang
Depends On:
TreeView+ depends on / blocked
Reported: 2020-01-23 12:41 UTC by David Eads
Modified: 2020-05-04 11:27 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2020-05-04 11:26:35 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Github openshift api pull 585 0 None closed Bug 1794376: config: disable IPv6DualStack feature flag 2020-12-24 08:50:41 UTC
Github openshift cluster-kube-apiserver-operator pull 758 0 None closed Bug 1794376: Remove IPv6 dualstack feature gate 2020-12-24 08:50:41 UTC
Red Hat Product Errata RHBA-2020:0581 0 None None None 2020-05-04 11:27:08 UTC

Description David Eads 2020-01-23 12:41:32 UTC
After enabling the IPv6DualStack feature gate on the the kube-apiserver, services cannot be created as normal. This blocks the Monitoring operator in particular.

We added the ability to strip feature gates to avoid reverting the api change.

Comment 2 Michal Fojtik 2020-02-10 10:45:32 UTC
This is POST until we merge the KAS-O bump;

Comment 4 Xingxing Xia 2020-02-24 01:58:38 UTC
Ke Wang, this is easy to verify, just check: under KAS pod's kube-apiserver process's configuration file, the field apiServerArguments.feature-gates does not include the one in bug title, and / or check KAS pod logs about feature gates exclude the one in bug title.
More knowledge about feature gates for you: from the PR's file config/v1/types_feature.go, feature gate sets include Default, CustomNoUpgrade, TechPreviewNoUpgrade and LatencySensitive. Each one defines what feature gates is Enabled and Disabled. "Default" is used when `oc get FeatureGate cluster -o yaml` spec.featureSet is empty. CustomNoUpgrade or TechPreviewNoUpgrade is used like bug 1731228#c17. For the one in bug title, per PR comment, it would not be supported currently

Comment 5 Ke Wang 2020-02-24 08:24:53 UTC
Verified with OCP build as below,

$ oc version
Client Version: v4.4.0
Server Version: 4.4.0-0.nightly-2020-02-24-020331
Kubernetes Version: v1.17.1

- Steps, 
Selected on KAS pod and check the configuration file, check the  default apiServerArguments of feature-gates, 

$ kubeapiserver_pod=$(oc get pod -n openshift-kube-apiserver | grep kube-apiserver | head -1 | awk '{print $1}')

$ oc rsh -n openshift-kube-apiserver  $kubeapiserver_pod

sh-4.2# cat /etc/kubernetes/static-pod-resources/configmaps/config/config.yaml| python -m json.tool
"feature-gates": [

We can see the IPv6DualStack feature gate was removed.

Comment 7 errata-xmlrpc 2020-05-04 11:26:35 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, and where to find the updated
files, follow the link below.

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


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