SUDO-centos7

 This article describes the process of granting sudo access to a new or existing user on CentOS®.

Create a new user

1. Create a new user by using the adduser command followed by the new user's <username> as shown in the following example:

   [root@server-01 ~]# adduser newuser
   

2. Use the passwd command followed by the new user's <username> to set up a password for newuser. Enter the new password in the verification prompt twice.

   [root@server-01 ~]# passwd newuser
   Changing password for user newuser.
   New password:
   Retype new password:
   passwd: all authentication tokens updated successfully
   

Grant root permissions to a new or existing user

1. Edit the sudoers file by using the following command:

   [root@server-01 ~]# visudo
   

2. You then see a version similar to following text:

   ## Next comes the main part: which users can run what software on
   ## which machines (the sudoers file can be shared between multiple
   ## systems).
   ## Syntax:
   ##
   ##      user    MACHINE=COMMANDS
   ##
   ## The COMMANDS section may have other options added to it.
   ##
   ## Allow root to run any commands anywhere
   root    ALL=(ALL)       ALL
   
   ## Allows members of the 'sys' group to run networking, software,
   ## service management apps and more.
   # %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS
   
   ## Allows people in group wheel to run all commands
   %wheel  ALL=(ALL)       ALL
   
   ## Same thing without a password
   # %wheel        ALL=(ALL)       NOPASSWD: ALL
   
   ## Allows members of the users group to mount and unmount the
   ## cdrom as root
   # %users  ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom
   
   ## Allows members of the users group to shutdown this system
   # %users  localhost=/sbin/shutdown -h now
   
   ## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)
   #includedir /etc/sudoers.d
   

3. Press the i key on your keyboard to enter insert mode. Next press the j key to move the cursor down and the k key to move it up to the following section:

   ## Allow root to run any commands anywhere
   root    ALL=(ALL)       ALL
   

4. Add the newly created user by inserting <username> ALL=(ALL) ALL on a new line as show in the following example:

   ## Allow root to run any commands anywhere
   root    ALL=(ALL)       ALL
   newuser ALL=(ALL)       ALL
   

5. Press the i key to exit insert mode, followed by typing :wq to save and exit.

Verify permission change

1. Use the su command followed by - <username> to access the new user account.

   [root@server-01 ~]# su - newuser
   [newuser@server-01 ~]$ 
   

2. Use the sudo -i command to test if the new user account can elevate permissions. Enter the new user's password. Verify these steps by using the following example:

   [newuser@server-01 ~]$ sudo -i
   
   We trust you have received the usual lecture from the local System
   Administrator. It usually boils down to these three things:
   
    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.
   
   [sudo] password for newuser:
   [root@server-01 ~]# 
   

3. Use the whoami command to verify you are currently the root user.

   [root@server-01 ~]# whoami
   root