Add support for mixed node pools in EKS

We have added support for mixed node pools on AWS.

Previously our EKS solution supported only a single type of spot instances in a pool. This caused problems when a certain type is out of capacity or when there’s lower prices for another instance type with similar requirements.

Mixed node pools allows us to make spot-backed node pools more robust by adding other instance types as options. When a certain instance type is not available the autoscaling group will fall back to one of the other types to fill the need.

If you want more information about this or you want this configured on your cluster(s) please let us know.

# example:
        - type: t3a.large
          weight: 1
        - type: t3.large
          weight: 1
        - type: t3.xlarge
          weight: 2
        - type: t3a.xlarge
          weight: 2

mixed node pool