to allow the user to be able to execute linux command

add the <user_name> to the 

/etc/sudoers 

e.g line add

support ALL=(ALL) NOPASSWD:ALL

Because the file is a readonly file, you first need to change the file permission to allow write to the file by root user

chmod g+rw /etc/sudoers

and you have to change it back to readonly file

chmod g-r /etc/sudoers