printf-style format is also available in terraform:
`format("vm%d-disk%d", 0, 3)` produces `vm0-disk3`
You can test it in the terraform "repl":
```
$ terraform console
> format("vm%d-disk%d", 0, 3)
"vm0-disk3"
> format("%02d", 1)
"01"
```
https://developer.hashicorp.com/terraform/language/functions/format
