Bug 1783353

Summary:	kcm doesn't work on IPv6
Product:	OpenShift Container Platform	Reporter:	Maciej Szulik <maszulik>
Component:	kube-controller-manager	Assignee:	Maciej Szulik <maszulik>
Status:	CLOSED ERRATA	QA Contact:	zhou ying <yinzhou>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	4.3.0	CC:	aos-bugs, mfojtik, yinzhou
Target Milestone:	---
Target Release:	4.3.0
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1783352	Environment:
Last Closed:	2020-01-23 11:19:25 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1783352
Bug Blocks:

Description Maciej Szulik 2019-12-13 15:48:26 UTC

+++ This bug was initially created as a clone of Bug #1783352 +++

Description of problem:
If you say net.Listen("tcp", "0.0.0.0:10357"), golang will actually create a dual-stack IPv4/IPv6 listening socket. But for historical reasons (having to do with bad IPv6 compat in older kube I think), we default to passing "tcp4" (the default value of configv1.ServingInfo.BindNetwork) instead of "tcp", forcing IPv4-only.

There is no reason these days for servers on the pod network to enforce IPv4-only, so this overrides the default for kube-controller-manager.

--- Additional comment from Maciej Szulik on 2019-12-13 16:47:59 CET ---

This was fixed in https://github.com/openshift/cluster-kube-controller-manager-operator/pull/320

Comment 2 zhou ying 2019-12-19 01:54:03 UTC

Checked with payload: 4.3.0-0.nightly-2019-12-18-215416 , the issue has fixed:

[root@dhcp-140-138 ~]# oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.3.0-0.nightly-2019-12-18-215416   True        False         8m20s   Cluster version is 4.3.0-0.nightly-2019-12-18-215416

sh-4.4# netstat -pan |grep 10357
tcp6       0      0 :::10357                :::*                    LISTEN      36344/cluster-polic

Comment 4 errata-xmlrpc 2020-01-23 11:19:25 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.

https://access.redhat.com/errata/RHBA-2020:0062