I use apache2-mpm-itk to run one of my web applications with a custom uid and gid, both for audit and security reasons. This works nicely, however I am not sure what kind of privileges this user would need. I am currently doing something like
useradd mywebapp -U -d/tmp -c"Custom webapp User" but that creates pretty much a regular user.
So first a newbie question: how do I add a 'system' user that can that cannot be used for e.g. ssh'in or does not appear in the login screen on Ubuntu Desktop?
And what kind of privileges would I need to give this user? E.g. I assume that www-data can write to the Apache log files, so it needs something more than a regular user. But at the same time I don't want to give it more privileges than necessary to run my webapp, definitely not root.