I'd like to create a user and a group both called subversion on a RHEL 5 system. I looked at the man page for useradd and I guess the command would be just be...
useradd subversion
However, not sure how to avoid creating a home dir. Also, I don't want it to be a user that can log in to the system.
The main purpose is just to provide an owner for a SVN repository.
You can use the following command:
useradd -r subversion
For more info, check manual pages with this command:
man useradd
You will find in this documentation the following flag that can be used for your purpose.
-r, --system create a system account
The -r flag will create a system user - one which does not have a password, a home dir and is unable to login.
You can use the -M switch (make sure it's a capital) to ensure no home directory will be created:
useradd -M subversion
then lock the account to prevent logging in:
usermod -L subversion
Another solution to create a system user, using adduser :
adduser --system --no-create-home --group yourusername
You can remove --group if you don't need group yourusername, and --no-create-home if you do need a home for this user.
As mentionned by py4on in comments, on some systems one may need to use the --disabled-login option in order to, well, disable login for this user. It seems to be the default behaviour under Debian, though.
Beware that the numeric ID of the user will be of a system account. You can fix the uid using the --uid option, though.
Finally, note that on some systems (e.g. Fedora) adduser is a symlink to useradd, in which case this answer is not valid.
The cleanest answer to the original question is to run the command:
adduser subversion --shell=/bin/false
And if you don't want the home directory either:
adduser subversion --shell=/bin/false --no-create-home
or, if you want an even more locked down system user (Normally this won't create a home directory - it has been reported that it will still create a home directory in linux mint as per comment below)
adduser subversion --system --group
All these commands will create a group with the same name as the user
The safest form of doing this would be to use adduser like so:
$ adduser -r -s /bin/nologin subversion
NOTE: Be sure to include -s /sbin/nologin to disable any login shell from being made available to the account.
$ grep subversion /etc/passwd /etc/shadow
/etc/passwd:subversion:x:496:496::/home/subversion:/bin/nologin
/etc/shadow:subversion:!!:17232::::::
However there's no directory:
$ ll /home | grep subversion
$
Confirm that the account is otherwise usable:
$ sudo -u subversion whoami
subversion
$ sudo -u subversion date
Tue Mar 7 08:58:57 EST 2017
If you need to remove this account:
$ userdel subversion -r
userdel: subversion mail spool (/var/spool/mail/subversion) not found
userdel: subversion home directory (/home/subversion) not found
$
And confirm:
$ grep rtim-hc-user /etc/passwd /etc/shadow
$
In Debian, you could create a system user (without home directory) and login shell:
useradd --system --shell=/usr/sbin/nologin <username>
If your nologin program is in /sbin/nologin, please change accordingly.
On a CentOS 7 machine you can use the following commands:
If the user does not exist:
useradd testuser --shell=/sbin/nologin
if you want to modify an existing user:
usermod testuser --shell=/sbin/nologin
Start by generating an encrypted password for the user with a maximum of 8 characters long by doing:
openssl passwd -crypt new_password_less_than_eight_chars_long
Then you do:
useradd -m -g groupname -G otherGroupsSeperatedByComma -p encryptedPassword username
useradd -s /sbin/nologin -M subversion
-s, set shell as /sbin/nologin - which will set user nologin accesss
-M, do not create users home directory
