Declarative primitive for referencing AWS Instance resources.
Supported anchor items: VpcId, State (defaults to pending and running, pass "*" for all states except shutting-down and terminated, pass null for all states), InstanceId, ImageId (required for creation), KeyName, SubnetId, InstanceType, PublicIpAddress (Bool), PrivateIpAddresses, UserData
Supported properties: Tags, SecurityGroups, State (running/stopped), SourceDestCheck.