I am a new student about vagrant. I just found that I can change to root by "sudo su -" without entering a password when inside the box supervised by Vagrant. Curiously I checked the "/etc/sudoers" and found nothing about user vagrant. Can anyone kindly explain this?
/etc/sudoers include another file which contains the NOPASSWD line.
vagrant@ubuntu-12:~$ sudo cat /etc/sudoers.d/vagrant
%vagrant ALL=NOPASSWD:ALL