Command Line – How to Add a User as a New Sudoer

command linesudouser-management

After I add a user using adduser, I can't see it via System > Administration > Users and Groups unless I log out and then log in again. Is that normal?

Also, can I set a newly added user as a sudoer or do I have to change that only after adding it? How can I do that via the shell?

Finally, can I delete the original user that was created upon initial installation of Ubuntu, or is this user somehow 'special'?

Best Answer

Just add the user to the sudo group:

sudo adduser <username> sudo

The change will take effect the next time the user logs in.

This works because /etc/sudoers is pre-configured to grant permissions to all members of this group (You should not have to make any changes to this):

# Allow members of group sudo to execute any command
%sudo   ALL=(ALL:ALL) ALL

As long as you have access to a user that is in the same groups as your "original" user, you can delete the old one.

Realistically, there are also other groups your new user should be a member of. If you set the Account type of a user to Administrator in Users Settings, it will be placed in at least all of these groups:

adm sudo lpadmin sambashare

Because your system configuration may vary, I suggest taking a look at the output of groups <username> to see what groups are normally in use.

Related Solutions

Ubuntu – What can a user do without sudo

In principle, a user created in that way cannot do any damage outside his/her own home directory. As you noticed, a regular user does have access to various directories (e.g. in /, /usr/, /tmp). This is a necessity, because most user-accessible programs are located in /usr/bin and /bin. If the user didn't have (read-only) access to these directories, he/she wouldn't be able to run any programs. However, a regular user doesn't have accesss to home directories of other users.

You can use the ls -l command to see permissions on a file or directory. See https://help.ubuntu.com/community/FilePermissions for more information on file permissions.

It is possible to limit an ssh user to only a few programs. See for http://www.pizzashack.org/rssh/ and http://www.cyberciti.biz/tips/linux-unix-restrict-shell-access-with-rssh.html for the rssh tool, which limits the user to only run copying tools like scp and rsync. Such users won't be able to log in normally to get a shell and run other commands.

Another option is to create a 'chroot' or 'jail' environment. See this AskUbuntu question.

Ubuntu – Ubuntu 14.04: New user created from command line has missing features

First notice that it's better to use adduser and not useradd.

Now back to your command:

You should run the command in the following manner:

sudo useradd -m -c "Samwise the Brave" sam  -s /bin/bash

man useradd

  -s, --shell SHELL
           The name of the user's login shell. The default is to leave this
           field blank, which causes the system to select the default login
           shell specified by the SHELL variable in /etc/default/useradd, or
           an empty string by default.

 -m, --create-home
           Create the user's home directory if it does not exist. The files
           and directories contained in the skeleton directory (which can be
           defined with the -k option) will be copied to the home directory.

           By default, if this option is not specified and CREATE_HOME is not
           enabled, no home directories are created.

So you miss to use -s to add your login shell and the -m to create your home.

If you want to add multiple users in the same time, it's better to use the command `newusers`. It'll simplify your task.

man newusers

DESCRIPTION

   The newusers command reads a file of user name and clear-text password
   pairs and uses this information to update a group of existing users or
   to create new users. Each line is in the same format as the standard
   password file (see passwd(5)) with the exceptions explained below:

   pw_name:pw_passwd:pw_uid:pw_gid:pw_gecos:pw_dir:pw_shell

Here some tutorial about newusers command:

Best Answer

Related Solutions

Ubuntu – What can a user do without sudo

Ubuntu – Ubuntu 14.04: New user created from command line has missing features

If you want to add multiple users in the same time, it's better to use the command newusers. It'll simplify your task.

Related Question

If you want to add multiple users in the same time, it's better to use the command `newusers`. It'll simplify your task.