@Alexsandra I've made you QA Contact on this BZ since you were able to verify the parent BZ.
OCP 4.5: 4.5.0-0.nightly-2020-10-05-204452 Steps to reproduce: 1. Change resolv.conf file on one of the masters (I addede the line "nameserver 127.0.0.1") [core@master-0-0 ~]$ sudo vi /etc/resolv.conf 2. Verify that the haproxy-monitor pod was restarted: [core@master-0-0 ~]$ sudo crictl ps | grep haproxy-monitor f5f09a971e61f 9fae0d9500dcd3c705e17d6c9c7afc41adb7713de390ae7cc751e5408201798e 3 seconds ago Running haproxy-monitor 4 4c9f0b437e7c9 3. Be sure that the haproxy-monitor pod was restarted because the "failed liveness probe": [core@master-0-0 ~]$ journalctl -u kubelet | grep "liveness probe" Oct 06 14:24:55 master-0-0 hyperkube[2343]: I1006 14:24:55.565294 2343 event.go:278] Event(v1.ObjectReference{Kind:"Pod", Namespace:"openshift-kni-infra", Name:"haproxy-master-0-0", UID:"ccda7847ab5cefa71f1f91518c07131c", APIVersion:"v1", ResourceVersion:"", FieldPath:"spec.containers{haproxy-monitor}"}): type: 'Normal' reason: 'Killing' Container haproxy-monitor failed liveness probe, will be restarted 4. Verify that container resolv.conf file is the same as on the master node (first line was added on the step 1): [core@master-0-0 ~]$ sudo crictl exec -it 2a94810301fa6 /bin/sh sh-4.2# cat /etc/resolv.conf # Generated by KNI resolv prepender NM dispatcher script search ocp-edge-cluster-0.qe.lab.redhat.com nameserver 192.168.123.112 nameserver 127.0.0.1 nameserver 192.168.123.1 5. The pod was restarted and in the Running state: [kni@provisionhost-0-0 ~]$ oc get pods -n openshift-kni-infra | grep haproxy-master-0-0 haproxy-master-0-0 2/2 Running 5 78m Before backport: When resolv.conf file changed on one of the masters (step 1) nothing happens.
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 4.5.15 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. https://access.redhat.com/errata/RHBA-2020:4228