Feature Overview (aka. Goal Summary)  

This feature tracks the ability for customers to perform a Day-2 operation to upgrade their node pools to a specific x.y.z version.

Similar to XCMSTRAT-1016, node pool versions have two restrictions based on the control plane version. With a control plane version of 4.15.10:

1. Its version must be less than or equal to the control plane version (i.e. any 4.13.z or 4.15.[0-10]-(ec/rc))
2. Its y-stream version must not have more than 2 versions of skew with the control plane (i.e. 4.13.z is ok, but 4.12.z would not be ok)

Goals (aka. expected user outcomes)

• As a customer, I can view available upgrade versions for my existing node pools
• As a customer, I can initiate an upgrade for a node pool to another version

Out of Scope

• Scheduling node pool upgrades could be out of scope depending on whether XCMSTRAT-1015 is complete or not. If not complete, we should create a follow up feature for scheduling node pool upgrades.