Bug 2016275

Summary: github.com can not be resolved inside pods where cluster is running on openstack.
Product: OpenShift Container Platform Reporter: OpenShift BugZilla Robot <openshift-bugzilla-robot>
Component: NetworkingAssignee: Miheer Salunke <misalunk>
Networking sub component: DNS QA Contact: Shudi Li <shudili>
Status: CLOSED ERRATA Docs Contact:
Severity: high    
Priority: high CC: aos-bugs, dollierp, gouyang, hongli, misalunk, mjurc, mmasters, msimka, ppitonak, varadhya, xiuwang
Version: 4.8Keywords: Reopened
Target Milestone: ---   
Target Release: 4.8.z   
Hardware: Unspecified   
OS: Unspecified   
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-11-02 14:42:06 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 2009210    
Bug Blocks:    

Comment 1 Miciah Dashiel Butler Masters 2021-10-26 16:05:03 UTC
This is a severe issue but not a regression, so setting blocker-.

Comment 5 Shudi Li 2021-10-28 03:22:36 UTC
Verified it with 4.8.0-0.nightly-2021-10-27-154740 on IPI on OpenStack and passed.

% oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.8.0-0.nightly-2021-10-27-154740   True        False         13m     Cluster version is 4.8.0-0.nightly-2021-10-27-154740

2.check bufsize in all the nodes, which is 512 as expected.
% oc debug node/shudi-48-os1-lqhd9-master-0
Starting pod/shudi-48-os1-lqhd9-master-0-debug ...
To use host binaries, run `chroot /host`
Pod IP:
If you don't see a command prompt, try pressing enter.
sh-4.4# chroot /host
sh-4.4# cat /etc/coredns/Corefile
. {
    bufsize 512
    health :18080
    forward . {
        policy sequential
    cache 30

3. Can carry out dns query of github.com successfully in another pod
% oc rsh centos-pod
sh-4.4# dig  github.com

; <<>> DiG 9.11.13-RedHat-9.11.13-6.el8_2.1 <<>> github.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8444
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

; EDNS: version: 0, flags:; udp: 512
; COOKIE: 4a78c5694924aa22 (echoed)
;github.com.			IN	A

github.com.		30	IN	A

;; Query time: 5 msec
;; WHEN: Thu Oct 28 03:12:09 UTC 2021
;; MSG SIZE  rcvd: 77


4. check the log from all dns pods under openshift-openstack-infra NS(Without carrying the dns query in the dns pod)
% oc -n openshift-openstack-infra logs coredns-shudi-48-os1-lqhd9-master-0 -c coredns
[INFO] plugin/reload: Running configuration MD5 = f5121b6db390e887b6cc8ced3a7db15e
linux/amd64, go1.16.6, 
[INFO] Reloading
[INFO] plugin/reload: Running configuration MD5 = f339170bf4c691c6b5b5bd274dfd1fa3
[INFO] Reloading complete
[INFO] Reloading
[INFO] plugin/reload: Running configuration MD5 = d6f2c2274e669f419008077e91778234
[INFO] Reloading complete

Comment 7 errata-xmlrpc 2021-11-02 14:42:06 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 (OpenShift Container Platform 4.8.18 bug fix 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.