title: Provision EC2 Instance in an abitrary availability zone via cloudformation
body: <p>My AWS solution spans over 3 availability zones. In my backend the user is able to trigger a heavy compute job with beefy px instances. Therefore I wrote a CFN template, which provision all resorucess to execute the compute job (secret store, IAM Role, EC2 instance, log group). However when I try to create the template, it returns with a 500 and states that no capacity for my instance type is available for the availability zone i choose. My template provides a subnet for the EC2 instance and an availability zone for the attached volume. In the end I don't care in which availability zone the ec2 is provisioned as long it is in one of my subnets. Does someone know a way to provision an EC2 instance and it's volume (with cloudforamtion) by not specifically choosing one availability zone, but rather provide a range of subnets/availability zones ?</p>
  <p>TLDR:
  Does someone know a way to provision an EC2 instance and it's volume (with cloudforamtion) by not specifically choosing one availability zone, but rather provide a range of subnets/availability zones ?</p>