We are attempting to filter a set of AWS subnets for creating an ASG.
In a VPC, we have some subnets tagged as “Network=private”. When creating an ASG for worker instances, we need to set the ASG’s AZs and subnets to the AZs and subnets of all private subnets in the VPC. So, being able to with_items over the subnets and filtering on tags “Network=private” is useful.
For AWS work, filtering AWS entities (hosts, IAM roles, subnets, VPC’, etc…) on one or more tags seems like it would be common.