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://uapi-group.org/specifications/specs/discoverable_partitions_specification

        2. Users, Groups, UIDs and GIDs on systemd systems
           https://systemd.io/UIDS-GIDS