Function ordinal 

fn ordinal(resource_name: &str) -> &str

The trailing ordinal of a Materialize resource name, named environment-{org_uuid}-{ordinal}.

environment-controller derives the ordinal the same way, in ordinal() in the cloud repo (src/environment/src/util.rs). The two must agree, because the un-prefixed form of the name this module builds has to equal the one environment-controller registers.