mirror of
https://github.com/systemd/systemd.git
synced 2024-12-27 07:22:31 +03:00
f2cca38e46
The man page didn't really say what we are mapping and with what patterns. Let's fix that.
164 lines
7.6 KiB
XML
164 lines
7.6 KiB
XML
<?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">
|
|
|
|
<!--
|
|
SPDX-License-Identifier: LGPL-2.1+
|
|
-->
|
|
|
|
<refentry id="nss-mymachines" conditional='ENABLE_NSS_MYMACHINES'>
|
|
|
|
<refentryinfo>
|
|
<title>nss-mymachines</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>nss-mymachines</refentrytitle>
|
|
<manvolnum>8</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>nss-mymachines</refname>
|
|
<refname>libnss_mymachines.so.2</refname>
|
|
<refpurpose>Provide hostname resolution for local
|
|
container instances.</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<para><filename>libnss_mymachines.so.2</filename></para>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<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
|
|
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 (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 provides name resolution for user and group identifiers mapped to containers. All names from
|
|
the range allocated to a given container <replaceable>container</replaceable> are exposed on the host as
|
|
<literal>vu-<replaceable>container</replaceable>-<replaceable>uid</replaceable></literal> and
|
|
<literal>vg-<replaceable>container</replaceable>-<replaceable>gid</replaceable></literal> (see example below). This
|
|
functionality only applies to containers using user namespacing (see the description of
|
|
<option>--private-users</option> in
|
|
<citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>).</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>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>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<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>
|
|
|
|
<!-- synchronize with other nss-* man pages and factory/etc/nsswitch.conf -->
|
|
<programlisting>passwd: compat <command>mymachines</command> systemd
|
|
group: compat <command>mymachines</command> systemd
|
|
shadow: compat
|
|
|
|
hosts: files <command>mymachines</command> resolve [!UNAVAIL=return] dns myhostname
|
|
networks: files
|
|
|
|
protocols: db files
|
|
services: db files
|
|
ethers: db files
|
|
rpc: db files
|
|
|
|
netgroup: nis</programlisting>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>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
|
|
|
|
$ getent passwd vu-rawhide-0 vu-rawhide-81
|
|
vu-rawhide-0:*:20119552:65534:vu-rawhide-0:/:/sbin/nologin
|
|
vu-rawhide-81:*:20119633:65534:vu-rawhide-81:/:/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
|
|
|
|
$ 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>,
|
|
<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>
|