man/sysusers.d.xml

   1 <?xml version="1.0"?>
   2 <!--*-nxml-*-->
   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!--
   5   This file is part of systemd.
   6
   7   Copyright 2014 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
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  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 -->
  22 <refentry id="sysusers.d">
  23
  24         <refentryinfo>
  25                 <title>sysusers.d</title>
  26                 <productname>systemd</productname>
  27
  28                 <authorgroup>
  29                         <author>
  30                                 <contrib>Developer</contrib>
  31                                 <firstname>Lennart</firstname>
  32                                 <surname>Poettering</surname>
  33                                 <email>lennart@poettering.net</email>
  34                         </author>
  35                 </authorgroup>
  36         </refentryinfo>
  37
  38         <refmeta>
  39                 <refentrytitle>sysusers.d</refentrytitle>
  40                 <manvolnum>5</manvolnum>
  41         </refmeta>
  42
  43         <refnamediv>
  44                 <refname>sysusers.d</refname>
  45                 <refpurpose>Declarative allocation of system users and groups</refpurpose>
  46         </refnamediv>
  47
  48         <refsynopsisdiv>
  49                 <para><filename>/usr/lib/sysusers.d/*.conf</filename></para>
  50         </refsynopsisdiv>
  51
  52         <refsect1>
  53                 <title>Description</title>
  54
  55                 <para><command>systemd-sysusers</command> uses the
  56                 files from <filename>/usr/lib/sysusers.d/</filename>
  57                 to create system users and groups at package
  58                 installation or boot time. This tool may be used for
  59                 allocating system users and groups only, it is not
  60                 useful for creating non-system users and groups, as it
  61                 accessed <filename>/etc/passwd</filename> and
  62                 <filename>/etc/group</filename> directly, bypassing
  63                 any more complex user database, for example any
  64                 database involving NIS or LDAP.</para>
  65
  66         </refsect1>
  67
  68         <refsect1>
  69                 <title>File Format</title>
  70
  71                 <para>Each file shall be named in the style of
  72                 <filename><replaceable>package</replaceable>.conf</filename>.</para>
  73
  74                 <para>All files are sorted by their filename in
  75                 lexicographic order, regardless of which of the
  76                 directories they reside in. If multiple files specify
  77                 the same user or group, the entry in the file with the
  78                 lexicographically earliest name will be applied, all
  79                 all other conflicting entries will be logged as
  80                 errors. Users and groups are
  81                 processed in the order they are listed.</para>
  82
  83                 <para>The file format is one line per user or group
  84                 containing name, ID and GECOS field description:</para>
  85
  86                 <programlisting># Type Name ID GECOS
  87 u httpd 440 "HTTP User"
  88 u authd /usr/bin/authd "Authorization user"
  89 g input - -</programlisting>
  90
  91                 <refsect2>
  92                         <title>Type</title>
  93
  94                         <para>The type consists of a single
  95                         letter. The following line types are
  96                         understood:</para>
  97
  98                         <variablelist>
  99                                 <varlistentry>
 100                                         <term><varname>u</varname></term>
 101                                         <listitem><para>Create a
 102                                         system user and group of the
 103                                         specified name should they not
 104                                         exist yet. The user's primary
 105                                         group will be set to the group
 106                                         bearing the same name. The
 107                                         user's shell will be set to
 108                                         <filename>/sbin/login</filename>,
 109                                         the home directory to
 110                                         <filename>/</filename>. The
 111                                         account will be created
 112                                         disabled, so that logins are
 113                                         not allowed.</para></listitem>
 114                                 </varlistentry>
 115
 116                                 <varlistentry>
 117                                         <term><varname>g</varname></term>
 118                                         <listitem><para>Create a
 119                                         system group of the specified
 120                                         name should it not exist
 121                                         yet. Note that
 122                                         <varname>u</varname>
 123                                         implicitly create a matching
 124                                         group. The group will be
 125                                         created with no password
 126                                         set.</para></listitem>
 127                                 </varlistentry>
 128                         </variablelist>
 129                 </refsect2>
 130
 131                 <refsect2>
 132                         <title>Name</title>
 133
 134                         <para>The name field specifies the user or
 135                         group name. It should be be shorter than 256
 136                         characters and avoid any non-ASCII characters,
 137                         and not begin with a numeric character. It is
 138                         strongly recommended to pick user and group
 139                         names that are unlikely to clash with normal
 140                         users created by the administrator. A good
 141                         scheme to guarantee this is by prefixing all
 142                         system and group names with the underscore,
 143                         and avoiding too generic names.</para>
 144                 </refsect2>
 145
 146                 <refsect2>
 147                         <title>ID</title>
 148
 149                         <para>The numeric 32bit UID or GID of the
 150                         user/group. Do not use IDs 65535 or
 151                         4294967295, as they have special placeholder
 152                         meanings. Specify "-" for automatic UID/GID
 153                         allocation for the user or
 154                         group. Alternatively, specify an absolute path
 155                         in the file system. In this case the UID/GID
 156                         is read from the path's owner/group. This is
 157                         useful to create users whose UID/GID match the
 158                         owners of pre-existing files (such as SUID or
 159                         SGID binaries).</para>
 160                 </refsect2>
 161
 162                 <refsect2>
 163                         <title>GECOS</title>
 164
 165                         <para>A short, descriptive string for users to
 166                         be created, enclosed in quotation marks. Note
 167                         that this field may not contain colons.</para>
 168                 </refsect2>
 169
 170         </refsect1>
 171
 172         <refsect1>
 173                 <title>See Also</title>
 174                 <para>
 175                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 176                         <citerefentry><refentrytitle>systemd-sysusers</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 177                 </para>
 178         </refsect1>
 179
 180 </refentry>