Setting blocker+ because this breaks the install for SNO+private.  

The issue probably lies in the generation of the default ingresscontroller manifest that the installer uses when the install-config specifies that a private cluster is desired.

Is this a regression from 4.9, or is this also broken on 4.9 (and probably earlier releases too)?

The issue can be reproduced in 4.9.0-0.nightly-2022-01-20-172411

1.
% oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.9.0-0.nightly-2022-01-20-172411   True        False         59m     Error while reconciling 4.9.0-0.nightly-2022-01-20-172411: the cluster operator ingress is degraded
% 

2.
% oc get node
NAME                                        STATUS   ROLES           AGE   VERSION
ip-10-0-62-116.us-east-2.compute.internal   Ready    master,worker   70m   v1.22.3+e790d7f
%

3.
% oc get co/ingress
NAME      VERSION                             AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
ingress   4.9.0-0.nightly-2022-01-20-172411   True        False         True       65m     The "default" ingress controller reports Degraded=True: DegradedConditions: One or more other status conditions indicate a degraded state: PodsScheduled=False (PodsNotScheduled: Some pods are not scheduled: Pod "router-default-6b6fbf7f7f-qfkzs" cannot be scheduled: 0/1 nodes are available: 1 node(s) didn't match pod anti-affinity rules. Make sure you have sufficient worker nodes.), DeploymentReplicasAllAvailable=False (DeploymentReplicasNotAvailable: 1/2 of replicas are available)
%

Thanks!  Because this is not a regression, I am clearing the blocker flag.  However, I have already posted a fix for review anyway.

After discussing with the installer team, we've decided that the appropriate way to resolve the issue is to change the operator's defaulting behavior when spec.replicas is omitted on an IngressController.

Blocked on getting a reviewer for <https://github.com/openshift/api/pull/1103>.  Moving this BZ off of 4.10.0; we'll get it in a later release.

This BZ is somewhat related to this proposed enhancement: <https://github.com/openshift/enhancements/pull/1041>.  I'll keep this BZ on the backlog for now.

https://github.com/openshift/cluster-ingress-operator/pull/728/commits/d52a837623d29d8b265bf3fa9e395a37be778f78 for https://issues.redhat.com/browse/MGMT-9797 should have fixed the issue.  Please verify and let me know if there is still an issue.

Verified it with 4.11.0-0.nightly-2022-10-26-170309 on a sno cluster
1.
% oc get clusterversion
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.11.0-0.nightly-2022-10-26-170309   True        False         12m     Cluster version is 4.11.0-0.nightly-2022-10-26-170309
%

2.
% oc get infrastructures.config.openshift.io cluster -oyaml
status:
  apiServerInternalURI: https://api-int.shudi-411snop12.qe.devcluster.openshift.com:6443
  apiServerURL: https://api.shudi-411snop12.qe.devcluster.openshift.com:6443
  controlPlaneTopology: SingleReplica
  etcdDiscoveryDomain: ""
  infrastructureName: shudi-411snop12-2tc8f
  infrastructureTopology: SingleReplica       <---
  platform: AWS
  platformStatus:
    aws:
      region: us-east-2
    type: AWS
% 

3
% oc get node
NAME                                        STATUS   ROLES           AGE   VERSION
ip-10-0-54-255.us-east-2.compute.internal   Ready    master,worker   31m   v1.24.6+5157800
% 

4. check the router-pod, only one pod as expected
shudi@Shudis-MacBook-Pro ~ % oc -n openshift-ingress get pods
NAME                             READY   STATUS    RESTARTS      AGE
router-default-c86b8754f-jkj8m   1/1     Running   3 (22m ago)   29m
% 

5.
% oc get co/ingress
NAME      VERSION                              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
ingress   4.11.0-0.nightly-2022-10-26-170309   True        False         False      21m     
%

The change mentioned in comment 11 shipped in the 4.11.0 GA release, so I am changing the resolution of this BZ to "CURRENTRELEASE".