How do I grant sudo privileges to an existing user?

Question

I want to grant a newly created user sudo privileges in Ubuntu.

I tried

sudo adduser hduser admin

but it says no admin group exists. How can I do it?

Solution 1

You need to add the user hduser to the sudo group (which is the "administrators" group in Ubuntu).

If you have already created the user, you can add the user to the sudo group by running the following command in a Terminal:

sudo usermod -a -G sudo hduser

Solution 2

Instead you can try,

sudo adduser hduser sudo

In Ubuntu you need to add the user only to the group sudo.

Solution 3

1) Become root. You can do this using sudo -i or becoming root the old fashioned way su -

2) Run visudo

3) I changed this portion of the sudoers file to have my chosen users become sudo users, and you can add users similarly (blank lines introduce to format cleanly):

## User Aliases
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname
## rather than USERALIAS
# User_Alias ADMINS = jsmith, mikem dbadmin 
ALL=(ALL) ALL
ics ALL=(ALL) ALL 
csm ALL=(ALL) ALL 
coa ALL=(ALL) ALL

4) Press : and x to write the changes to sudoers and exit vi.

Solution 4

Edit the sudoers file: sudo visudo

and add:

user    ALL=(ALL:ALL) ALL

View more solutions

Comments

[Mitch]

What is the output of sudo visudo?

[Adrian]

This was changed recently, which is the reason for the confusion.

[Jamess]

sudo adduser <username> sudo - did the trick for me. Second sudo is the group name instead of sudo

[Jacob Foshee]

Note that the user must log off, then back on again for this change to take effect.

[Dan Dascalescu]

Why bother editing /etc/sudoers when the adduser command will work?

[Dan Dascalescu]

This seems needlessly complicated. Why bother running visudo when the adduser command will do what you want?

[JBB]

@dan-dascalescu - $ sudo adduser username sudo won't work if the 'sudo' group does not exist. So adding the user manually is certainly an option. However, it's certainly more elegant to create a sudo group, add it to the sudoers file (e.g. via visudo), then add the appropriate user(s) to that user group.

[Ashish Ratan]

not working ubuntu 14

[Ashish Ratan]

Usage: usermod [options] LOGIN Options: -c, --comment COMMENT new value of the GECOS field -d, --home HOME_DIR new home directory for the user account -e, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE -f, --inactive INACTIVE set password inactive after expiration to INACTIVE -g, --gid GROUP force use GROUP as new primary group -G, --groups GROUPS new list of supplementary GROUPS -a, --append append the user to the supplemental GROUPS

[Marcel]

@JarrettBarnett That was the case for me. Thank you for your answer.

[vivekyad4v]

Yes , @JacobFoshee is right - "user must log off, then back on again for this change to take effect."

[Jalal Sordo]

still if i use visudo on the user i just added to sudo I will get permission denied, why is that ?

[d a i s y]

@Zanna You have edited sudo visudo /etc/sudoers Is it correct? AFAIK, it is either sudo visudo or sudo nano /etc/sudoers

[Zanna]

ah @Lnux you're right, but you should always use visudo to edit /etc/sudoers because it stops you from making a fatal syntax error. I corrected

[MrSmith42]

No problem here using ubuntu 16.

[Nullpointer]

How do i remove sudo access from existing user ?

[jeffmcneill]

FYI, In RHEL/CentOS it is: sudo usermod -aG wheel hduser

[The Fool]

@DanDascalescu maybe because for some people it doesnt work?