man/systemd-sysusers.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="systemd-sysusers"
   7     xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-sysusers</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-sysusers</refentrytitle>
  16     <manvolnum>8</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-sysusers</refname>
  21     <refname>systemd-sysusers.service</refname>
  22     <refpurpose>Allocate system users and groups</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <cmdsynopsis>
  27       <command>systemd-sysusers</command>
  28       <arg choice="opt" rep="repeat">OPTIONS</arg>
  29       <arg choice="opt" rep="repeat"><replaceable>CONFIGFILE</replaceable></arg>
  30     </cmdsynopsis>
  31
  32     <para><filename>systemd-sysusers.service</filename></para>
  33   </refsynopsisdiv>
  34
  35   <refsect1>
  36     <title>Description</title>
  37
  38     <para><command>systemd-sysusers</command> creates system users and groups, based on files in the format
  39     described in
  40     <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
  41     </para>
  42
  43     <para>If invoked with no arguments, it applies all directives from all files found in the directories
  44     specified by
  45     <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>. When
  46     invoked with positional arguments, if option <option>--replace=<replaceable>PATH</replaceable></option>
  47     is specified, arguments specified on the command line are used instead of the configuration file
  48     <replaceable>PATH</replaceable>. Otherwise, just the configuration specified by the command line
  49     arguments is executed. The string <literal>-</literal> may be specified instead of a filename to instruct
  50     <command>systemd-sysusers</command> to read the configuration from standard input. If the argument is a
  51     relative path, all configuration directories are searched for a matching file and the file found that has
  52     the highest priority is executed. If the argument is an absolute path, that file is used directly without
  53     searching of the configuration directories.</para>
  54   </refsect1>
  55
  56   <refsect1>
  57     <title>Options</title>
  58
  59     <para>The following options are understood:</para>
  60
  61     <variablelist>
  62       <varlistentry>
  63         <term><option>--root=<replaceable>root</replaceable></option></term>
  64         <listitem><para>Takes a directory path as an argument. All
  65         paths will be prefixed with the given alternate
  66         <replaceable>root</replaceable> path, including config search
  67         paths. </para>
  68
  69         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
  70       </varlistentry>
  71
  72       <varlistentry>
  73         <term><option>--image=<replaceable>image</replaceable></option></term>
  74
  75         <listitem><para>Takes a path to a disk image file or block device node. If specified all operations
  76         are applied to file system in the indicated disk image. This is similar to <option>--root=</option>
  77         but operates on file systems stored in disk images or block devices. The disk image should either
  78         contain just a file system or a set of file systems within a GPT partition table, following the
  79         <ulink url="https://uapi-group.org/specifications/specs/discoverable_partitions_specification">Discoverable Partitions
  80         Specification</ulink>. For further information on supported disk images, see
  81         <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
  82         switch of the same name.</para>
  83
  84         <xi:include href="version-info.xml" xpointer="v247"/></listitem>
  85       </varlistentry>
  86
  87       <xi:include href="standard-options.xml" xpointer="image-policy-open" />
  88
  89       <varlistentry>
  90         <term><option>--replace=<replaceable>PATH</replaceable></option></term>
  91         <listitem><para>When this option is given, one or more positional arguments
  92         must be specified. All configuration files found in the directories listed in
  93         <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  94         will be read, and the configuration given on the command line will be
  95         handled instead of and with the same priority as the configuration file
  96         <replaceable>PATH</replaceable>.</para>
  97
  98         <para>This option is intended to be used when package installation scripts
  99         are running and files belonging to that package are not yet available on
 100         disk, so their contents must be given on the command line, but the admin
 101         configuration might already exist and should be given higher priority.
 102         </para>
 103
 104         <example>
 105           <title>RPM installation script for radvd</title>
 106
 107           <programlisting>echo 'u radvd - "radvd daemon"' | \
 108           systemd-sysusers --replace=/usr/lib/sysusers.d/radvd.conf -</programlisting>
 109
 110           <para>This will create the radvd user as if
 111           <filename>/usr/lib/sysusers.d/radvd.conf</filename> was already on disk.
 112           An admin might override the configuration specified on the command line by
 113           placing <filename>/etc/sysusers.d/radvd.conf</filename> or even
 114           <filename>/etc/sysusers.d/00-overrides.conf</filename>.</para>
 115
 116           <para>Note that this is the expanded form, and when used in a package, this
 117           would be written using a macro with "radvd" and a file containing the
 118           configuration line as arguments.</para>
 119         </example>
 120
 121           <xi:include href="version-info.xml" xpointer="v238"/>
 122         </listitem>
 123       </varlistentry>
 124
 125       <varlistentry>
 126         <term><option>--dry-run</option></term>
 127         <listitem><para>Process the configuration and figure out what entries would be created, but don't
 128         actually write anything.</para>
 129
 130         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
 131       </varlistentry>
 132
 133       <varlistentry>
 134         <term><option>--inline</option></term>
 135         <listitem><para>Treat each positional argument as a separate configuration
 136         line instead of a file name.</para>
 137
 138         <xi:include href="version-info.xml" xpointer="v238"/></listitem>
 139       </varlistentry>
 140
 141       <xi:include href="standard-options.xml" xpointer="cat-config" />
 142       <xi:include href="standard-options.xml" xpointer="tldr" />
 143       <xi:include href="standard-options.xml" xpointer="no-pager" />
 144       <xi:include href="standard-options.xml" xpointer="help" />
 145       <xi:include href="standard-options.xml" xpointer="version" />
 146     </variablelist>
 147   </refsect1>
 148
 149   <refsect1>
 150     <title>Credentials</title>
 151
 152     <para><command>systemd-sysusers</command> supports the service credentials logic as implemented by
 153     <varname>ImportCredential=</varname>/<varname>LoadCredential=</varname>/<varname>SetCredential=</varname>
 154     (see <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
 155     details). The following credentials are used when passed in:</para>
 156
 157     <variablelist class='system-credentials'>
 158       <varlistentry>
 159         <term><varname>passwd.hashed-password.<replaceable>user</replaceable></varname></term>
 160         <listitem><para>A UNIX hashed password string to use for the specified user, when creating an entry
 161         for it. This is particularly useful for the <literal>root</literal> user as it allows provisioning
 162         the default root password to use via a unit file drop-in or from a container manager passing in this
 163         credential. Note that setting this credential has no effect if the specified user account already
 164         exists. This credential is hence primarily useful in first boot scenarios or systems that are fully
 165         stateless and come up with an empty <filename>/etc/</filename> on every boot.</para>
 166
 167         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 168       </varlistentry>
 169
 170       <varlistentry>
 171         <term><varname>passwd.plaintext-password.<replaceable>user</replaceable></varname></term>
 172
 173         <listitem><para>Similar to <literal>passwd.hashed-password.<replaceable>user</replaceable></literal>
 174         but expect a literal, plaintext password, which is then automatically hashed before used for the user
 175         account. If both the hashed and the plaintext credential are specified for the same user the
 176         former takes precedence. It's generally recommended to specify the hashed version; however in test
 177         environments with weaker requirements on security it might be easier to pass passwords in plaintext
 178         instead.</para>
 179
 180         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 181       </varlistentry>
 182
 183       <varlistentry>
 184         <term><varname>passwd.shell.<replaceable>user</replaceable></varname></term>
 185
 186         <listitem><para>Specifies the shell binary to use for the specified account when creating it.</para>
 187
 188         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 189       </varlistentry>
 190
 191       <varlistentry>
 192         <term><varname>sysusers.extra</varname></term>
 193
 194         <listitem><para>The contents of this credential may contain additional lines to operate on. The
 195         credential contents should follow the same format as any other <filename>sysusers.d/</filename>
 196         drop-in. If this credential is passed it is processed after all of the drop-in files read from the
 197         file system.</para>
 198
 199         <xi:include href="version-info.xml" xpointer="v252"/></listitem>
 200       </varlistentry>
 201     </variablelist>
 202
 203     <para>Note that by default the <filename>systemd-sysusers.service</filename> unit file is set up to
 204     inherit the <literal>passwd.hashed-password.root</literal>,
 205     <literal>passwd.plaintext-password.root</literal>, <literal>passwd.shell.root</literal> and
 206     <literal>sysusers.extra</literal> credentials from the service manager. Thus, when invoking a container
 207     with an unpopulated <filename>/etc/</filename> for the first time it is possible to configure the root
 208     user's password to be <literal>systemd</literal> like this:</para>
 209
 210     <para><programlisting># systemd-nspawn --image=… --set-credential=passwd.hashed-password.root:'$y$j9T$yAuRJu1o5HioZAGDYPU5d.$F64ni6J2y2nNQve90M/p0ZP0ECP/qqzipNyaY9fjGpC' …</programlisting></para>
 211
 212     <para>Note again that the data specified in this credential is consulted only when creating an account
 213     for the first time, it may not be used for changing the password or shell of an account that already
 214     exists.</para>
 215
 216     <para>Use <citerefentry project='man-pages'><refentrytitle>mkpasswd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 217     for generating UNIX password hashes from the command line.</para>
 218   </refsect1>
 219
 220   <refsect1>
 221     <title>Exit status</title>
 222
 223     <para>On success, 0 is returned, a non-zero failure code
 224     otherwise.</para>
 225   </refsect1>
 226
 227   <refsect1>
 228     <title>See Also</title>
 229     <para><simplelist type="inline">
 230       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 231       <member><citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
 232       <member><ulink url="https://systemd.io/UIDS-GIDS">Users, Groups, UIDs and GIDs on systemd systems</ulink></member>
 233       <member><citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
 234       <member><citerefentry project='man-pages'><refentrytitle>mkpasswd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 235     </simplelist></para>
 236   </refsect1>
 237
 238 </refentry>