NAME¶

sysusers.d - Declarative allocation of system users and groups

SYNOPSIS¶

#Type Name       ID                  GECOS              Home directory Shell
u     user_name  uid                 "User Description" /home/dir      /path/to/shell
u     user_name  uid:gid             "User Description" /home/dir      /path/to/shell
u     user_name  /file/owned/by/user "User Description" /home/dir      /path/to/shell
g     group_name gid
g     group_name /file/owned/by/group
m     user_name  group_name
r     -          lowest-highest

DESCRIPTION¶

systemd-sysusers uses the files from sysusers.d directory to create system users and groups and to add users to groups, at package installation or boot time. This tool may be used to allocate system users and groups only, it is not useful for creating non-system (i.e. regular, "human") users and groups, as it accesses /etc/passwd and /etc/group directly, bypassing any more complex user databases, for example any database involving NIS or LDAP.

CONFIGURATION DIRECTORIES AND PRECEDENCE¶

Each configuration file shall be named in the style of package.conf or package-part.conf. The second variant should be used when it is desirable to make it easy to override just this part of configuration.

Files in /etc/sysusers.d override files with the same name in /usr/lib/sysusers.d and /run/sysusers.d. Files in /run/sysusers.d override files with the same name in /usr/lib/sysusers.d. Packages should install their configuration files in /usr/lib/sysusers.d. Files in /etc/sysusers.d are reserved for the local administrator, who may use this logic to override the configuration files installed by vendor packages. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same path, the entry in the file with the lexicographically earliest name will be applied. All later entries for the same user and group names will be logged as warnings.

If the administrator wants to disable a configuration file supplied by the vendor, the recommended way is to place a symlink to /dev/null in /etc/sysusers.d/ bearing the same filename.

CONFIGURATION FILE FORMAT¶

The file format is one line per user or group containing name, ID, GECOS field description, home directory, and login shell:

#Type Name     ID             GECOS                 Home directory Shell
u!    httpd    404            "HTTP User"
u!    _authd   /usr/bin/authd "Authorization user"
u!    postgres -              "Postgresql Database" /var/lib/pgsql /usr/libexec/postgresdb
g     input    -              -
m     _authd   input
u     root     0              "Superuser"           /root          /bin/zsh
r     -        500-900

Empty lines and lines beginning with the "#" character are ignored, and may be used for commenting.

SPECIFIERS¶

Specifiers can be used in the "Name", "ID", "GECOS", "Home directory", and "Shell" fields. An unknown or unresolvable specifier is treated as invalid configuration. The following expansions are understood:

Table 1. Specifiers available

IDEMPOTENCE¶

Note that
systemd-sysusers will do nothing if the specified users or groups already exist or the users are members of specified groups, so normally there is no reason to override sysusers.d vendor configuration, except to block certain users or groups from being created.

SEE ALSO¶

systemd(1), systemd-sysusers(8)

NOTES¶

1.

User/Group Name Syntax