Support for multiple resources of the same GVR in the ManagedClusterAddOn resource about addon-framework

[qiujian16]

/assign @qiujian16

@zhujian7 @haoqing0110 we have to discuss about it on whether it is feasible. The major concern, is if the user select specify multiple configurations with the same gvk, do we merge them or use the one with the highest order or it is purely addon's decision.

[JoaoBraveCoding]

The major concern, is if the user select specify multiple configurations with the same gvk, do we merge them or use the one with the highest order or it is purely addon's decision.

Maybe it's because I'm not familiar with all the inner workings of the addon-framework but what about taking all the resources with the same GVK and hashing them all to compute the specHash? The "only" concerning part I see is the "default" behaviour that you can set on ClusterManagedAddon... 🤔 A way out I see is if we add to ConfigMeta a bool value (e.g singleton) which would enable the default behaviour. So when singleton is true the addon framework will merge the default config with the ManagedClusterAddon config, otherwise it will require users to provide that config