1 <?xml version='
1.0'
?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
9 <refentry id=
"nss-systemd" conditional='ENABLE_NSS_SYSTEMD'
>
12 <title>nss-systemd
</title>
13 <productname>systemd
</productname>
17 <refentrytitle>nss-systemd
</refentrytitle>
18 <manvolnum>8</manvolnum>
22 <refname>nss-systemd
</refname>
23 <refname>libnss_systemd.so
.2</refname>
24 <refpurpose>Provide UNIX user and group name resolution for dynamic users and groups.
</refpurpose>
28 <para><filename>libnss_systemd.so
.2</filename></para>
32 <title>Description
</title>
34 <para><command>nss-systemd
</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the
35 GNU C Library (
<command>glibc
</command>), providing UNIX user and group name resolution for dynamic users and
36 groups allocated through the
<varname>DynamicUser=
</varname> option in systemd unit files. See
37 <citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details on
40 <para>This module also ensures that the root and nobody users and groups (i.e. the users/groups with the UIDs/GIDs
41 0 and
65534) remain resolvable at all times, even if they aren't listed in
<filename>/etc/passwd
</filename> or
42 <filename>/etc/group
</filename>, or if these files are missing.
</para>
44 <para>To activate the NSS module, add
<literal>systemd
</literal> to the lines starting with
45 <literal>passwd:
</literal> and
<literal>group:
</literal> in
<filename>/etc/nsswitch.conf
</filename>.
</para>
47 <para>It is recommended to place
<literal>systemd
</literal> after the
<literal>files
</literal> or
48 <literal>compat
</literal> entry of the
<filename>/etc/nsswitch.conf
</filename> lines so that
49 <filename>/etc/passwd
</filename> and
<filename>/etc/group
</filename> based mappings take precedence.
</para>
53 <title>Example
</title>
55 <para>Here is an example
<filename>/etc/nsswitch.conf
</filename> file that enables
56 <command>nss-systemd
</command> correctly:
</para>
58 <!-- synchronize with other nss-* man pages and factory/etc/nsswitch.conf -->
59 <programlisting>passwd: compat mymachines
<command>systemd
</command>
60 group: compat mymachines
<command>systemd
</command>
63 hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
71 netgroup: nis
</programlisting>
76 <title>See Also
</title>
78 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
79 <citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
80 <citerefentry><refentrytitle>nss-resolve
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
81 <citerefentry><refentrytitle>nss-myhostname
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
82 <citerefentry><refentrytitle>nss-mymachines
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
83 <citerefentry project='man-pages'
><refentrytitle>nsswitch.conf
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
84 <citerefentry project='man-pages'
><refentrytitle>getent
</refentrytitle><manvolnum>1</manvolnum></citerefentry>