Bug 1994859

Summary:	Windows Containers on Windows Nodes get assigned the DNS Server IP “172.30.0.10”, which is wrong, if the default kubernetes subnet is not used
Product:	OpenShift Container Platform	Reporter:	Swapnil Dalela <sdalela>
Component:	Windows Containers	Assignee:	jvaldes
Status:	CLOSED ERRATA	QA Contact:	Ronnie Rasouli <rrasouli>
Severity:	high	Docs Contact:
Priority:	high
Version:	4.8	CC:	aliryan, aos-bugs, jvaldes, mohashai, rrasouli
Target Milestone:	---
Target Release:	4.10.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Cause: Hard-coded Cluster DNS (172.30.0.10) in kubelet configuration template. Consequence: Windows Containers on Windows Nodes get assigned a wrong DNS Server IP, hence DNS resolution does not work. Fix: Remove the hard-coded Cluster DNS information and parametrize the value as a command-line argument. Result: Windows Containers on Windows Nodes get assigned a valid DNS Server IP and DNS resolution works for Windows workloads.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-03-28 09:36:25 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:
Bug Depends On:
Bug Blocks:	2020350

Description Swapnil Dalela 2021-08-18 02:48:57 UTC

Description of problem:

When a cluster is created with a different cidr and service network, The ClusterDNS IP in kubelet.conf should change accordingly. However on a windows node, it is still 172.30.0.10.


How reproducible:

Always


Steps to Reproduce:

Check the kubelet.conf on any windows node.

Actual results:

The clusterDNS is 172.30.0.10 even when the serviceNetwork is 100.123.0.0./16.


Expected results:

The cluster DNS should be a IP in 100.123.0.0/16 which is the serviceNetwork for the cluster.

Comment 2 Mohammad Saif Shaikh 2021-08-18 15:35:09 UTC

*** Bug 1992228 has been marked as a duplicate of this bug. ***

Comment 4 Ronnie Rasouli 2021-12-01 06:07:11 UTC

oc get network cluster -oyaml
apiVersion: config.openshift.io/v1
kind: Network
metadata:
  creationTimestamp: "2021-11-30T11:43:26Z"
  generation: 2
  name: cluster
  resourceVersion: "3110"
  uid: 9198cca0-4dcc-468c-b9fb-15f9e7465f91
spec:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  externalIP:
    policy: {}
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16
status:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  clusterNetworkMTU: 8901
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16


"clusterDNS":["172.30.0.10"]


verified on version "5.0.0+69a4fee"

Comment 7 errata-xmlrpc 2022-03-28 09:36:25 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 (Moderate: Windows Container Support for Red Hat OpenShift 5.0.0 [security 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-2022:0577