man
8 SYSTEMD-SYSUSERS
SYSTEMD-SYSUSERS(8) systemd-sysusers SYSTEMD-SYSUSERS(8)
NAME
systemd-sysusers, systemd-sysusers.service - Allocate system users and
groups
SYNOPSIS
systemd-sysusers [OPTIONS...] [CONFIGFILE...]
systemd-sysusers.service
DESCRIPTION
systemd-sysusers creates system users and groups, based on files in the
format described in sysusers.d(5).
If invoked with no arguments, it applies all directives from all files
found in the directories specified by sysusers.d(5). When invoked with
positional arguments, if option --replace=PATH is specified, arguments
specified on the command line are used instead of the configuration
file PATH. Otherwise, just the configuration specified by the command
line arguments is executed. The string "-" may be specified instead of
a filename to instruct systemd-sysusers to read the configuration from
standard input. If the argument is a relative path, all configuration
directories are searched for a matching file and the file found that
has the highest priority is executed. If the argument is an absolute
path, that file is used directly without searching of the configuration
directories.
OPTIONS
The following options are understood:
--root=root
Takes a directory path as an argument. All paths will be prefixed
with the given alternate root path, including config search paths.
--image=image
Takes a path to a disk image file or block device node. If
specified all operations are applied to file system in the
indicated disk image. This is similar to --root= but operates on
file systems stored in disk images or block devices. The disk image
should either contain just a file system or a set of file systems
within a GPT partition table, following the Discoverable Partitions
Specification[1]. For further information on supported disk images,
see systemd-nspawn(1)'s switch of the same name.
--replace=PATH
When this option is given, one or more positional arguments must be
specified. All configuration files found in the directories listed
in sysusers.d(5) will be read, and the configuration given on the
command line will be handled instead of and with the same priority
as the configuration file PATH.
This option is intended to be used when package installation
scripts are running and files belonging to that package are not yet
available on disk, so their contents must be given on the command
line, but the admin configuration might already exist and should be
given higher priority.
Example 1. RPM installation script for radvd
echo 'u radvd - "radvd daemon"' | \
systemd-sysusers --replace=/usr/lib/sysusers.d/radvd.conf -
This will create the radvd user as if
/usr/lib/sysusers.d/radvd.conf was already on disk. An admin might
override the configuration specified on the command line by placing
/etc/sysusers.d/radvd.conf or even
/etc/sysusers.d/00-overrides.conf.
Note that this is the expanded form, and when used in a package,
this would be written using a macro with "radvd" and a file
containing the configuration line as arguments.
--dry-run
Process the configuration and figure out what entries would be
created, but don't actually write anything.
--inline
Treat each positional argument as a separate configuration line
instead of a file name.
--cat-config
Copy the contents of config files to standard output. Before each
file, the filename is printed as a comment.
--no-pager
Do not pipe output into a pager.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
CREDENTIALS
systemd-sysusers supports the service credentials logic as implemented
by LoadCredential=/SetCredential= (see systemd.exec(1) for details).
The following credentials are used when passed in:
"passwd.hashed-password.user"
A UNIX hashed password string to use for the specified user, when
creating an entry for it. This is particularly useful for the
"root" user as it allows provisioning the default root password to
use via a unit file drop-in or from a container manager passing in
this credential. Note that setting this credential has no effect if
the specified user account already exists. This credential is hence
primarily useful in first boot scenarios or systems that are fully
stateless and come up with an empty /etc/ on every boot.
"passwd.plaintext-password.user"
Similar to "passwd.hashed-password.user" but expect a literal,
plaintext password, which is then automatically hashed before used
for the user account. If both the hashed and the plaintext
credential are specified for the same user the former takes
precedence. It's generally recommended to specify the hashed
version; however in test environments with weaker requirements on
security it might be easier to pass passwords in plaintext instead.
"passwd.shell.user"
Specifies the shell binary to use for the specified account when
creating it.
"sysusers.extra"
The contents of this credential may contain additional lines to
operate on. The credential contents should follow the same format
as any other sysusers.d/ drop-in. If this credential is passed it
is processed after all of the drop-in files read from the file
system.
Note that by default the systemd-sysusers.service unit file is set up
to inherit the "passwd.hashed-password.root",
"passwd.plaintext-password.root", "passwd.shell.root" and
"sysusers.extra" credentials from the service manager. Thus, when
invoking a container with an unpopulated /etc/ for the first time it is
possible to configure the root user's password to be "systemd" like
this:
# systemd-nspawn --image=... --set-credential=passwd.hashed-password.root:'$y$j9T$yAuRJu1o5HioZAGDYPU5d.$F64ni6J2y2nNQve90M/p0ZP0ECP/qqzipNyaY9fjGpC' ...
Note again that the data specified in this credential is consulted only
when creating an account for the first time, it may not be used for
changing the password or shell of an account that already exists.
Use mkpasswd(1) for generating UNIX password hashes from the command
line.
EXIT STATUS
On success, 0 is returned, a non-zero failure code otherwise.
SEE ALSO
systemd(1), sysusers.d(5), Users, Groups, UIDs and GIDs on systemd
systems[2], systemd.exec(1), mkpasswd(1)
NOTES
1. Discoverable Partitions Specification
https://systemd.io/DISCOVERABLE_PARTITIONS
2. Users, Groups, UIDs and GIDs on systemd systems
https://systemd.io/UIDS-GIDS
systemd 252 SYSTEMD-SYSUSERS(8)