chrismytton
commented
9 years ago It appears that despite me saying that this should work in IRC I forgot to take into account the restriction that MongoDB places on the database name length:
Database names cannot be empty and must have fewer than 64 characters
So actually the instance slug needs to take into account the length of config.MongoDB.popit_prefix for the current environment.
Increase the maximum label length to 63, allow labels to start with a number, but don't allow them to end with a hyphen. Explain that hyphens are allowed in the validation text.