At the moment in RHOAM the customer can specify a wildcard domain to be used in 3scale via an addon parameter in OCM. 

After 3scale is installed in RHOAM this addon parameter becomes redundant. SRE must follow an SOP to modify the wildcard domain. SOP here

This creates toil for SRE. 

The request is to expose this feature in 3scale / 3scale operator to allow RHOAM to update this dynamically. 

This is a long requested feature, see related jira THREESCALE-1096

Master admin can see the provider accounts admin portal (Admin domain) domains (see screenshot), however they can't change these domains.

There should be a way to change these domains using UI and API.

Things that need to generate error message:

– domain is already being used
– [developers add more info to this list please]

Let's document this here (see also this doc):
Who is this for - who will use it? Who should be able to use it? For RHOAM too?
What problem does it solve? For on-prem folks?
Limitation? (For example, only for SaaS, only for certain customers, etc.)
Do we provide it as a service? a support tool?
What could this break? for SaaS? for on-prem? for RHOAM?

This issue is for RHOAM customers. However, we should do our best to avoid splitting things into RHOAM versus on-prem versus SaaS. Let's make sure we have this defined for SaaS and on-prem folks as well. amasferr, we will need you for that...