Linux Add user in sudo/wheel, Enable root user login

usermod.md

Add user to group and make sudoer/nopassword-access

Ubuntu

• adduser username
• usermod -aG groupname username or gpasswd -a user_name group_name
  • usermod -aG sudo username
• visudo
  • username ALL=(ALL) NOPASSWD:ALL
• Remove a user from a group
  • deluser user_name group_name or gpasswd -d user_name group_name

Centos

• passwd username
• usermod -aG wheel username
• Adding user to group wheel
  • gpasswd -a username wheel
• Check User wheel
  • sudo lid -g wheel

Enable Root User to Login

• passwd root
• Edit the file /etc/gdm3/custom.conf and put under [daemon] section AllowRoot=true
• Commented the following line from the file /etc/pam.d/gdm-password
• auth required pam_succeed_if.so user != root quiet_success

Change User and User dir, User group -> from user Y to user X

• groupadd X
• usermod -d /home/X -m -g X -l X Y