<?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2016 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="nss-systemd"> <refentryinfo> <title>nss-systemd</title> <productname>systemd</productname> <authorgroup> <author> <contrib>Developer</contrib> <firstname>Lennart</firstname> <surname>Poettering</surname> <email>lennart@poettering.net</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>nss-systemd</refentrytitle> <manvolnum>8</manvolnum> </refmeta> <refnamediv> <refname>nss-systemd</refname> <refname>libnss_systemd.so.2</refname> <refpurpose>Provide UNIX user and group name resolution for dynamic users and groups.</refpurpose> </refnamediv> <refsynopsisdiv> <para><filename>libnss_systemd.so.2</filename></para> </refsynopsisdiv> <refsect1> <title>Description</title> <para><command>nss-systemd</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the GNU C Library (<command>glibc</command>), providing UNIX user and group name resolution for dynamic users and groups allocated through the <varname>DynamicUser=</varname> option in systemd unit files. See <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details on this option.</para> <para>This module also ensures that the root and nobody users and groups (i.e. the users/groups with the UIDs/GIDs 0 and 65534) remain resolvable at all times, even if they aren't listed in <filename>/etc/passwd</filename> or <filename>/etc/group</filename>, or if these files are missing.</para> <para>To activate the NSS module, add <literal>systemd</literal> to the lines starting with <literal>passwd:</literal> and <literal>group:</literal> in <filename>/etc/nsswitch.conf</filename>.</para> <para>It is recommended to place <literal>systemd</literal> after the <literal>files</literal> or <literal>compat</literal> entry of the <filename>/etc/nsswitch.conf</filename> lines so that <filename>/etc/passwd</filename> and <filename>/etc/group</filename> based mappings take precedence.</para> </refsect1> <refsect1> <title>Example</title> <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables <command>nss-systemd</command> correctly:</para> <programlisting>passwd: compat mymachines <command>systemd</command> group: compat mymachines <command>systemd</command> shadow: compat hosts: files mymachines resolve myhostname networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis</programlisting> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum></citerefentry> </para> </refsect1> </refentry>