<?xml version='1.0'?> <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
-<!--
- SPDX-License-Identifier: LGPL-2.1+
-
- 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/>.
--->
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="nss-systemd" conditional='ENABLE_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>
<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>
+ <refpurpose>UNIX user and group name resolution for user/group lookup via Varlink</refpurpose>
</refnamediv>
<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><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 services implementing the <ulink url="https://systemd.io/USER_GROUP_API">User/Group Record
+ Lookup API via Varlink</ulink>, such as the system and service manager
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> (for its
+ <varname>DynamicUser=</varname> feature, see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details),
+ <citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</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>This module preferably utilizes
+ <citerefentry><refentrytitle>systemd-userdbd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for resolving users and groups, but also works without the service running.</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>
</refsect1>
<refsect1>
- <title>Example</title>
+ <title>Configuration in <filename>/etc/nsswitch.conf</filename></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>
+ <!-- synchronize with other nss-* man pages and factory/etc/nsswitch.conf -->
+ <programlisting>passwd: compat <command>systemd</command>
+group: compat [SUCCESS=merge] <command>systemd</command>
shadow: compat
-hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
+hosts: mymachines resolve [!UNAVAIL=return] myhostname files dns
networks: files
protocols: db files
</refsect1>
+ <refsect1>
+ <title>Example: Mappings provided by <filename>systemd-machined.service</filename></title>
+
+ <para>The container <literal>rawhide</literal> is spawned using
+ <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>:
+ </para>
+
+ <programlisting># systemd-nspawn -M rawhide --boot --network-veth --private-users=pick
+Spawning container rawhide on /var/lib/machines/rawhide.
+Selected user namespace base 20119552 and range 65536.
+...
+
+$ machinectl --max-addresses=3
+MACHINE CLASS SERVICE OS VERSION ADDRESSES
+rawhide container systemd-nspawn fedora 30 169.254.40.164 fe80::94aa:3aff:fe7b:d4b9
+
+$ getent passwd vu-rawhide-0 vu-rawhide-81
+vu-rawhide-0:*:20119552:65534:vu-rawhide-0:/:/usr/sbin/nologin
+vu-rawhide-81:*:20119633:65534:vu-rawhide-81:/:/usr/sbin/nologin
+
+$ getent group vg-rawhide-0 vg-rawhide-81
+vg-rawhide-0:*:20119552:
+vg-rawhide-81:*:20119633:
+
+$ ps -o user:15,pid,tty,command -e|grep '^vu-rawhide'
+vu-rawhide-0 692 ? /usr/lib/systemd/systemd
+vu-rawhide-0 731 ? /usr/lib/systemd/systemd-journald
+vu-rawhide-192 734 ? /usr/lib/systemd/systemd-networkd
+vu-rawhide-193 738 ? /usr/lib/systemd/systemd-resolved
+vu-rawhide-0 742 ? /usr/lib/systemd/systemd-logind
+vu-rawhide-81 744 ? /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
+vu-rawhide-0 746 ? /usr/sbin/sshd -D ...
+vu-rawhide-0 752 ? /usr/lib/systemd/systemd --user
+vu-rawhide-0 753 ? (sd-pam)
+vu-rawhide-0 1628 ? login -- zbyszek
+vu-rawhide-1000 1630 ? /usr/lib/systemd/systemd --user
+vu-rawhide-1000 1631 ? (sd-pam)
+vu-rawhide-1000 1637 pts/8 -zsh
+</programlisting>
+ </refsect1>
+
<refsect1>
<title>See Also</title>
<para>
<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><refentrytitle>systemd-userdbd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-machined.service</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>
projects / thirdparty / systemd.git / blobdiff