sudoers disaster

[Karl Hegbloom]

On Wed, 2005-09-28 at 21:27 +0100, Robbo wrote:
> login as the user your know that should have admin rights and type in
> groups and check if "admin" is listed.  If it isn't you'll need to add
> it using "usermod -G admin username".  

No, that's wrong.  Use:

 adduser username admin

The 'usermod' command above will remove that user from all groups but
'admin'.  That's not quite what you want.  You want them to stay in all
of the groups they are in, plus 'admin'.

See:  man adduser, adduser --help, man deluser, deluser --help, man
useradd, man groupadd, groupadd --help, man usermod, man groupadd, man
groupmod.

> To do this (I presume you can't log in as root), you need to go into
> single user mode. 
> 
> To boot in single mode...
> 
> 1. You might have to press <ESC> to see your boot menu (you will see a
> prompt)
> 2. Choose the kernel you want to boot using the arrow buttons on your
> keyboard
> 3. Press "e" for edit

You may need to use 'p' and type the access password first, if you've
secured Grub by enabling the password in /boot/grub/menu.lst.  That's a
good idea if the computer is in an environment where you cannot trust
everyone who has physical access to it.

> 4. Press the "end" button on your keyboard, type in a comma space ", "
> and then type "single"

No comma, but use a space.  Or you can simply pick the "recovery mode"
menu item.

> 5. Press <ENTER> and than "b" to boot that kernel, this will take you
> into single user mode.

Yes.  And will prompt for the root password iff one has been set.  You
can set a root password with the 'passwd' command if you like.  There's
no reason to if you've secured the Grub menu.

-- 
Karl Hegbloom <hegbloom at pdx.edu>