Add a user that can gain root privileges in Ubuntu
You have created a user, and now you want to make this user (e.g. peter as an example) can gain root privileges.
Firstly, check your /etc/sudoers file
# sudo cat /etc/sudoers
You might found the following lines
# Members of the admin group may gain root privileges %admin ALL=(ALL) ALL john ALL=(ALL) ALL
If you have the line %admin ALL=(ALL) ALL, then you can add the user (e.g peter) to the admin group using the command:
# sudo usermod -g admin peter
Or you can edit the file /etc/sudoers to add your account manually
# sudo visudo
Append peter ALL=(ALL) ALL at the end..
%admin ALL=(ALL) ALL john ALL=(ALL) ALL peter ALL=(ALL) ALL