What does the numeric prefix mean for the files located in `/etc/sudoers.d`?

Question

I go to /etc/sudoers folder to check users who have sudo permission and found each file has a numeric prefix.

[email protected]:/etc/sudoers.d# ls
80-deploy-user  90-cloud-init-users README

What are they used for?

Answer 1

The files are read in alphabetical order. The numeric prefix sets the order that way. - user10489

Answer 2

It's all explained in man run-parts. run-parts is a tool for orderly processing of a bunch o' files (data, rules, definitions, etc), when you don't know all the filenames in advance. This allows for easier configuration management. All the software tools that use run-parts follow the same configuration file ordering. run-parts is an alternative to the "one giant config file" approach. 1GCF makes it more difficult to be sure one has found (and fixed) all the config entries one needs to. With run-parts, all of the config entries dealing with a single topic can be stored in a single dedicated file. The order imposed by run-parts makes it possible to "do" one part before or after another, which is handy, sometimes.