<?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+ -->
-<!--
- SPDX-License-Identifier: LGPL-2.1+
-
- This file is part of systemd.
-
- Copyright 2014 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-mymachines" conditional='ENABLE_MACHINED'>
+<refentry id="nss-mymachines" conditional='ENABLE_NSS_MYMACHINES'>
<refentryinfo>
<title>nss-mymachines</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-mymachines</refname>
<refname>libnss_mymachines.so.2</refname>
- <refpurpose>Provide hostname resolution for local
- container instances.</refpurpose>
+ <refpurpose>Hostname resolution for local container instances</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><command>nss-mymachines</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of
the GNU C Library (<command>glibc</command>), providing hostname resolution for the names of containers running
locally that are registered with
- <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. The
+ <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. The
container names are resolved to the IP addresses of the specific container, ordered by their scope. This
- functionality only applies to containers using network namespacing.</para>
+ functionality only applies to containers using network namespacing (see the description of
+ <option>--private-network</option> in
+ <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>).
+ Note that the name that is resolved is the one registered with <command>systemd-machined</command>, which
+ may be different than the hostname configured inside of the container.</para>
- <para>The module also resolves user and group IDs used by containers to user and group names indicating the
- container name, and back. This functionality only applies to containers using user namespacing.</para>
-
- <para>To activate the NSS module, add <literal>mymachines</literal> to the lines starting with
- <literal>hosts:</literal>, <literal>passwd:</literal> and <literal>group:</literal> in
- <filename>/etc/nsswitch.conf</filename>.</para>
+ <para>To activate the NSS module, add <literal>mymachines</literal> to the line starting with
+ <literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para>
<para>It is recommended to place <literal>mymachines</literal> after the <literal>files</literal> or
- <literal>compat</literal> entry of the <filename>/etc/nsswitch.conf</filename> lines to make sure that its mappings
- are preferred over other resolvers such as DNS, but so that <filename>/etc/hosts</filename>,
- <filename>/etc/passwd</filename> and <filename>/etc/group</filename> based mappings take precedence.</para>
+ <literal>compat</literal> entry of the <filename>/etc/nsswitch.conf</filename> line to make sure that its
+ mappings are preferred over other resolvers such as DNS, but so that <filename>/etc/hosts</filename>
+ based mappings take precedence.</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-mymachines</command> correctly:</para>
- <programlisting>passwd: compat <command>mymachines</command> systemd
-group: compat <command>mymachines</command> systemd
+ <!-- synchronize with other nss-* man pages and factory/etc/nsswitch.conf -->
+ <programlisting>passwd: compat systemd
+group: compat systemd
shadow: compat
-hosts: files <command>mymachines</command> resolve [!UNAVAIL=return] dns myhostname
+hosts: <command>mymachines</command> resolve [!UNAVAIL=return] myhostname files dns
networks: files
protocols: db files
</refsect1>
+ <refsect1>
+ <title>Example: Mappings provided by <filename>nss-mymachines</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
+
+$ ping -c1 rawhide
+PING rawhide(fe80::94aa:3aff:fe7b:d4b9%ve-rawhide (fe80::94aa:3aff:fe7b:d4b9%ve-rawhide)) 56 data bytes
+64 bytes from fe80::94aa:3aff:fe7b:d4b9%ve-rawhide (fe80::94aa:3aff:fe7b:d4b9%ve-rawhide): icmp_seq=1 ttl=64 time=0.045 ms
+...
+$ ping -c1 -4 rawhide
+PING rawhide (169.254.40.164) 56(84) bytes of data.
+64 bytes from 169.254.40.164 (169.254.40.164): icmp_seq=1 ttl=64 time=0.064 ms
+...
+
+# machinectl shell rawhide /sbin/ip a
+Connected to machine rawhide. Press ^] three times within 1s to exit session.
+1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
+ ...
+2: host0@if21: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
+ link/ether 96:aa:3a:7b:d4:b9 brd ff:ff:ff:ff:ff:ff link-netnsid 0
+ inet 169.254.40.164/16 brd 169.254.255.255 scope link host0
+ valid_lft forever preferred_lft forever
+ inet6 fe80::94aa:3aff:fe7b:d4b9/64 scope link
+ valid_lft forever preferred_lft forever
+Connection to machine rawhide terminated.
+</programlisting>
+ </refsect1>
+
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
projects / thirdparty / systemd.git / blobdiff