Ivan Levchenko

keys derived from resource attributres that cannot be determined until apply

1

when accessing outputs such as private_subnet_attributes_by_az, terraform throws an error like "... includes keys derived from resource attributes that cannot be determined until apply". this then requires a targeted apply...

determanistic subnet cidr calculation

3

when updating the `az_count`, i noticed that not all subnet cidr range calculations are deterministic. after changing the value from 1 to 2, for one of the subnets terraform triggered...

Expanding the work that [Bill Beesley](https://github.com/bbeesley) has done earlier by adding a feature flag that sets the old behavior as default + examples and tests. please see the original [MR](https://github.com/aws-ia/terraform-aws-vpc/pull/130)...