Create sudo.log on Ubuntu server

Create log file:

touch /var/log/sudo.log

Edit the file /etc/sudoers

visudo

Paste
Defaults logfile="/var/log/sudo.log"

Restart rsyslog
sudo systemctl restart rsyslog

View log
tail -f /var/log/sudo.log

Create New Sudo User in Ubuntu

Create a new user

sudo useradd -m -s /bin/bash -c "Administrative User" admin

Create a password for the admin user using the passwd utility

sudo passwd admin

To enable the user admin to invoke sudo to perform administrative tasks, you need to add the user to the sudo system group using the usermod command as follows, where the -a option means to append user to a supplementary group and -G specifies the group.
 
sudo usermod -aG sudo admin

Now test sudo access on a new user account by switching to admin’s account (enter admin’s account password when prompted).
 
su - admin

 

Make user change password in first login: 

sudo passwd -e username