Bug 1994859 - 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
Summary: Windows Containers on Windows Nodes get assigned the DNS Server IP “172.30.0....
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: Windows Containers
Version: 4.8
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
: 4.10.0
Assignee: jvaldes
QA Contact: Ronnie Rasouli
URL:
Whiteboard:
: 1992228 (view as bug list)
Depends On:
Blocks: 2020350
TreeView+ depends on / blocked
 
Reported: 2021-08-18 02:48 UTC by Swapnil Dalela
Modified: 2024-12-20 20:44 UTC (History)
5 users (show)

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.
Clone Of:
Environment:
Last Closed: 2022-03-28 09:36:25 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Github openshift windows-machine-config-bootstrapper pull 306 0 None Merged Bug 1994859: Parametrize Cluster DNS 2022-02-23 20:16:19 UTC
Github openshift windows-machine-config-operator pull 777 0 None Merged Bug 1994859: Get and pass Cluster DNS to wmcb.exe 2022-02-23 20:16:16 UTC

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


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