Sudo without password

How to run sudo command without prompting password:

  1. Create backup of /etc/sudoers:

     $ sudo cp /etc/sudoers /etc/sudoers.bak
  2. Then, using nano/vi to edit the /etc/sudoers file.

     $ sudo visudo

    By default visudo using vi editor, but if you want to use nano (for example).

    It will show similar like this and enter your preferred editor.

     $ sudo update-alternatives --config editor
     There are 4 choices for the alternative editor (providing /usr/bin/editor).
     Selection    Path                Priority   Status
     * 0          /bin/nano            40        auto mode
     1            /bin/ed             -100       manual mode
     2            /bin/nano            40        manual mode
     3            /usr/bin/vim.basic   30        manual mode
     4            /usr/bin/vim.tiny    15        manual mode
     Press <enter> to keep the current choice[*], or type selection number:
  3. Add or Edit your user to add the NO PASSWD privilege. It will show similar like this.

     # This file MUST be edited with the 'visudo' command as root.
     # Please consider adding local content in /etc/sudoers.d/ instead of
     # directly modifying this file.
     # See the man page for details on how to write a sudoers file.
     Defaults    env_reset
     Defaults    mail_badpass
     Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"
     # Host alias specification
     # User alias specification
     # Cmnd alias specification
     # User privilege specification
     root    ALL=(ALL:ALL) ALL
     # Members of the admin group may gain root privileges
     %admin ALL=(ALL) ALL
     # Allow members of group sudo to execute any command
     %sudo   ALL=(ALL:ALL) ALL
     # See sudoers(5) for more information on "#include" directives:
     #includedir /etc/sudoers.d
     $USER ALL=(ALL) NOPASSWD: ALL # $USER is your user in Unix/Linux host.
  4. To give it a try, you can save the new /etc/sudoers file and do:

     $ sudo su