I have customized Ubuntu using OEM install but I would like to customize the user that is created when the end user creates an account. The user by default is an administrator but I would like them to only be a standard user. Is there a way to achieve this?
I believe oem-config just resets the debconf values for a couple of modules, the interesting one here being
d-i passwd, which creates a user account during installation. Since this might be the only account which can login (the root account might be disabled),
d-i passwd automatically adds the account to the
sudo group, and there isn't an option to override this.
It does look like
oem-config provides a
late-command key which gets ran at the very end of the process, so I believe you could use that to remove any/all users from the
sudo group. I haven't tried this myself (I use preseed/kickseed for all my setup), but assuming it works the same as the preseed late_command, you can add a single (logical) line of shell code to be executed. Something like this ran from the terminal before reboot should do the trick:
echo "set oem-config/late-command sed -i '/^(sudo:x:[0-9]+:).*$/\1/' /etc/group" | debconf-communicate