introduce AppSet CRD

[cppforlife]

AppSet is meant to represent same App deployed in several variations (it's analogous to Pod to Deployment relation where each Pod gets a unique name):

• across a set of clusters (based on collection of kubeconfig secrets)
• across a set of namespaces (may be based on collection of service accounts?)
• with different data values (with different config maps)
• with different source configuration (e.g. different git branches)

[cppforlife]

idea: each AppSet could be implemented as a App CR itself that is build from ytt templates that creates App CR based on a list of values.

[iancoffey]

I would love to help out with this one, thanks :) I could create a proposal if appropriate.

[ewrenn8]

Hey @iancoffey @cppforlife, do the in progress packaging APIs satisfy the ask of this issue, or is there a different use case that still necessitates the need for an AppSet?

[neil-hickey]

@cppforlife still want an AppSet? :)