man/nss-mymachines.xml

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  10   Copyright 2014 Lennart Poettering
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  25
  26 <refentry id="nss-mymachines" conditional='ENABLE_MACHINED'>
  27
  28   <refentryinfo>
  29     <title>nss-mymachines</title>
  30     <productname>systemd</productname>
  31
  32     <authorgroup>
  33       <author>
  34         <contrib>Developer</contrib>
  35         <firstname>Lennart</firstname>
  36         <surname>Poettering</surname>
  37         <email>lennart@poettering.net</email>
  38       </author>
  39     </authorgroup>
  40   </refentryinfo>
  41
  42   <refmeta>
  43     <refentrytitle>nss-mymachines</refentrytitle>
  44     <manvolnum>8</manvolnum>
  45   </refmeta>
  46
  47   <refnamediv>
  48     <refname>nss-mymachines</refname>
  49     <refname>libnss_mymachines.so.2</refname>
  50     <refpurpose>Provide hostname resolution for local
  51     container instances.</refpurpose>
  52   </refnamediv>
  53
  54   <refsynopsisdiv>
  55     <para><filename>libnss_mymachines.so.2</filename></para>
  56   </refsynopsisdiv>
  57
  58   <refsect1>
  59     <title>Description</title>
  60
  61     <para><command>nss-mymachines</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of
  62     the GNU C Library (<command>glibc</command>), providing hostname resolution for the names of containers running
  63     locally that are registered with
  64     <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.  The
  65     container names are resolved to the IP addresses of the specific container, ordered by their scope. This
  66     functionality only applies to containers using network namespacing.</para>
  67
  68     <para>The module also resolves user and group IDs used by containers to user and group names indicating the
  69     container name, and back. This functionality only applies to containers using user namespacing.</para>
  70
  71     <para>To activate the NSS module, add <literal>mymachines</literal> to the lines starting with
  72     <literal>hosts:</literal>, <literal>passwd:</literal> and <literal>group:</literal> in
  73     <filename>/etc/nsswitch.conf</filename>.</para>
  74
  75     <para>It is recommended to place <literal>mymachines</literal> after the <literal>files</literal> or
  76     <literal>compat</literal> entry of the <filename>/etc/nsswitch.conf</filename> lines to make sure that its mappings
  77     are preferred over other resolvers such as DNS, but so that <filename>/etc/hosts</filename>,
  78     <filename>/etc/passwd</filename> and <filename>/etc/group</filename> based mappings take precedence.</para>
  79   </refsect1>
  80
  81   <refsect1>
  82     <title>Example</title>
  83
  84     <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables
  85     <command>nss-mymachines</command> correctly:</para>
  86
  87     <programlisting>passwd:         compat <command>mymachines</command> systemd
  88 group:          compat <command>mymachines</command> systemd
  89 shadow:         compat
  90
  91 hosts:          files <command>mymachines</command> resolve [!UNAVAIL=return] dns myhostname
  92 networks:       files
  93
  94 protocols:      db files
  95 services:       db files
  96 ethers:         db files
  97 rpc:            db files
  98
  99 netgroup:       nis</programlisting>
 100
 101   </refsect1>
 102
 103   <refsect1>
 104     <title>See Also</title>
 105     <para>
 106       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 107       <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 108       <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 109       <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 110       <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 111       <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 112       <citerefentry project='man-pages'><refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 113     </para>
 114   </refsect1>
 115
 116 </refentry>