My guidelines for default env var values are:
- A default must not injure production or, through omission, allow production to come to harm.
- A default must ease local development except where such a default would conflict with the First Law.
- A default must reflect the live environment as long as such reflection does not conflict with the First or Second Laws.
This format is inspired by Isaac Asimov’s Three Laws of Robotics.
Like Asimov’s Laws, I expect there are some odd cases when they’re pushed to their limits.