systemd/man/nss-mymachines.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

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<refentry id="nss-mymachines" conditional='ENABLE_MACHINED'>

  <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>
    <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 plugin for the GNU
    Name Service Switch (NSS) functionality of the GNU C Library
    (<command>glibc</command>) providing hostname resolution for
    container 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.</para>

    <para>The module also resolves user IDs used by containers to user
    names indicating the container name, and back.</para>

    <para>To activate the NSS modules, <literal>mymachines</literal>
    has to be added 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>
    near the end of the <filename>nsswitch.conf</filename> lines to
    make sure that its mappings are only used as fallback, and any
    other mappings, such as DNS or <filename>/etc/hosts</filename>
    based mappings take precedence.</para>
  </refsect1>

  <refsect1>
    <title>Example</title>

    <para>Here's an example <filename>/etc/nsswitch.conf</filename>
    file, that enables <command>mymachines</command> correctly:</para>

    <programlisting>passwd:         compat <command>mymachines</command>
group:          compat <command>mymachines</command>
shadow:         compat

hosts:          files dns <command>mymachines</command> 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-machined.service</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>