Background:

A recent PR (#246) introduced the sre-ingress-config-validation validating webhook configuration in ROSA. This change prevents customers from modifying the ingress.config, specifically in terms of setting a custom appsDomain for their applications.

[1]https://docs.openshift.com/container-platform/4.12/rest_api/config_apis/ingress-config-openshift-io-v1.html#:~:text=Description-,appsDomain,-string

Issue:

Since the implementation of this webhook, customers have lost the ability to declare a custom domain as the default for their applications via the appsDomain field in the ingress.config. This field, which can be modified post-installation, is crucial for customers needing to set up a custom default host for Routes.

Attempted Alternatives:

We explored using Ingress Controller sharding as an alternative, as detailed in the OpenShift Ingress Shard Documentation. However, this method did not effectively change the default hostname, leading to issues with route creation and necessitating manual hostname specification.

Expected Outcome: The implementation of this RFE would allow customers to easily set and modify their appsDomain to use custom domains for their applications

Current behavior , with second ingress controller enabled on the ROSA/OSD on 4.14+

While create the Route, it will need --hostname flag for the custom domain . e.g.

oc create route edge --service=hello-openshift testroute --hostname hello.$DOMAIN -n testapp 

Customer hope it could possible to use appsDomain field in the ingress.config as default domain for the applications and skip  the --hostname flag