Ubuntu Manpage: minsysusers - minimalistic sysusers.d conf files parser

NAME

       minsysusers - minimalistic sysusers.d conf files parser

SYNOPSIS

       /usr/sbin/minsysusers [--root=/path] file.conf [ file2.conf ... ]

DESCRIPTION

       minsysusers  takes  declaratives  conf  files  as  input  and creates system users and group according to
       sysusers.d(5) specifications. To create users and groups useradd, groupadd and usermod are used under the
       hood.
       Conf files are searched in /etc/sysusers.d/ and /usr/lib/sysusers.d/; files in /etc overrides files  with
       the same name in /usr.
       At  least  one  conf  file  must  be  given  on the command line and the file must exists in at least one
       searched path.

OPTIONS

       --root=/path/to/root
              takes a path to a root as argument; root must exists. Users and groups will be created  inside  of
              the  given  root; config files given on the command line will be searched inside root. This option
              can be specified only once for each minsysusers invocation.

DIFFERENCES WITH SYSTEMD-SYSUSERS

       conf files in /run/sysusers.d/ and /usr/local/lib/sysusers.d/  are  ignored,  only  /etc/sysusers.d/  and
       /usr/lib/sysusers.d/ are valid path for conf files.

       It's  not possible to have minsysusers parse all available conf files at once; even if more than one file
       is given on the command line, it processes each file and  calls  useradd,  groupadd  and  usermod  before
       processing the next one.

        Minsysusers supports a very small subset of command line options compared to systemd-sysusers; --root
        can  be  given  only  once,  all other options such as --image --replace --dry-run --inline --cat-config
       --tldr --no-pager --help --version are not supported.

SYSUSERS.D: IMPLEMENTATION DETAILS

Specifiers as described in sysusers.d(5) are not supported.

Types u, g, m, r are supported; conffile's lines are grouped by type and processed in the following
order: r, g, u and m. As a consequence, the order or lines in a conffile does not matter, except for r
type (see below).

Ranges in r lines are passed to useradd, usermod using -K thus overriding SYS_UID_ and SYS_GID_ key
values in /etc/login.defs. When multiple r lines are given, the range from the first one is used, ranges
from remaining r lines are discarded. When a UID is specified in ID field, and the UID is free, it takes
precedence over the range given with r line.

For u lines the default home is / and the default shell is /sbin/nologin . Both home and shell field
must start with / , be empty or set to - .
Gecos field value, if given, must be within double quotes; empty or - gecos is valid.
When u! is used, the account is locked with usermod -L .

For ID field, special values 65535 and 4294967295 are reserved and thus not valid. The ID field can be
specified in various form:
for u lines, the following entries are considered valid

500

500:600

500:groupname

-:groupname

-:600

/path/to/file

/path/to/dir

When a path is given if a system group for path's GID is not found, the system group is
automatically created. For all other ID entries where a groupname or a GID is specified, the
corresponding system group must already exists (it's ok to create it explicitly with a g line in
the same conf file).

for g lines, the following entries are considered valid

500

/path/to/file

/path/to/dir

when a path is given, the path's GID is used to create the system group; the UID of the path is
irrelevant.

for m lines it must be a groupname;

for r lines it must be either a single number or a min-max numeric range.

FILES

       /etc/sysusers.d/
       /usr/lib/sysusers.d/
       /etc/login.defs

AUTHOR

       Lorenzo Puliti <plorenzo@disroot.org>

                                                January 20, 2025                                  minsysusers(8)