ResourceReference should support Alias

[verysonglaa]

Current State

The ResourceReference (e.g., in PrivateLinkServiceConnection) currently allows referencing existing resources using group/kind/name or armId. However, our use case requires referencing resources by an alias, as demonstrated in this example. Unfortunately, using an alias as the armId is blocked by the current regex validation.

Proposed Improvement

Add support for using an alias in ResourceReference.
Alternatively, rename armId to id and allow it to accept both armId and aliases.

##Additional Context
A practical example of this requirement is configuring Elastic Cloud with Azure Private Link when accessed from AKS. This scenario is detailed in Elastic’s blog: Secure your deployments on Elastic Cloud with Azure Private Link.

[theunrepentantgeek]

Is alias something that's generally supported by all ARM references? From what I can tell, it is a peculiarity of the PrivateLink API.

We may need to introduce a custom version of ResourceReference that gets used specifically (and only) where aliases are permitted.

[theunrepentantgeek]

Alternatively, rename armId to id and allow it to accept both armId and aliases.

This would break all existing ASO resources using the armID property; we'll need to find a different solution.

[verysonglaa]

Understood, from a quick research it looks like alias is somewhat unique to Private Link Services as a global identifier. Seeing that I can think of 2 ways of handling it:

• having a custom version of ResourceReference as a type of the property privateLinkServiceReference in PrivateLinkServiceConnection like you proposed or
• having a second property e.g. named privateLinkServiceAlias with type string which is mutally exclusive to privateLinkServiceReference in PrivateLinkServiceConnection

Is alias something that's generally supported by all ARM references? From what I can tell, it is a peculiarity of the PrivateLink API.

We may need to introduce a custom version of ResourceReference that gets used specifically (and only) where aliases are permitted.