[question] Can we use different AMI images for different instance arch in mixed IGs?

There's a scalar field to specify the image AMI for an instance group: `.spec.image`

However, it is sometimes desirable to run instances of different architectures (arm64 + amd64) in the same instance group, using, for example, the spot mixedInstancesPolicy configuration.

Obviously, this will fail, since all the instance types must match the specified AMI architecture.

Part of the documentation at https://kops.sigs.k8s.io/instance_groups/#spotinstancepools suggests that there might be something of interest:

> The Spot pools are determined from the different instance types in the Overrides array of LaunchTemplate. Default if not set is 2.

However I found no further mention of how to configure this Overrides array, which apparently can be used to set AMIs for each specific instance type (as described in https://aws.amazon.com/blogs/compute/supporting-aws-graviton2-and-x86-instance-types-in-the-same-auto-scaling-group/).

Is there any workaround?

Start with the kOps instance groups documentation, especially the Spot instance pools section and its LaunchTemplate Overrides reference, then compare it with the AWS mixed-architecture Auto Scaling Group example. Determine whether kOps supports architecture-specific AMIs in one instance group; done should be a confirmed workaround or a clearly scoped implementation and documentation change.

Written by the indexing model from the issue text.