man/nss-mymachines.xml

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  23
  24 <refentry id="nss-mymachines" conditional='ENABLE_MACHINED'>
  25
  26   <refentryinfo>
  27     <title>nss-mymachines</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>Developer</contrib>
  33         <firstname>Lennart</firstname>
  34         <surname>Poettering</surname>
  35         <email>lennart@poettering.net</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>nss-mymachines</refentrytitle>
  42     <manvolnum>8</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>nss-mymachines</refname>
  47     <refname>libnss_mymachines.so.2</refname>
  48     <refpurpose>Provide hostname resolution for local
  49     container instances.</refpurpose>
  50   </refnamediv>
  51
  52   <refsynopsisdiv>
  53     <para><filename>libnss_mymachines.so.2</filename></para>
  54   </refsynopsisdiv>
  55
  56   <refsect1>
  57     <title>Description</title>
  58
  59     <para><command>nss-mymachines</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of
  60     the GNU C Library (<command>glibc</command>), providing hostname resolution for the names of containers running
  61     locally that are registered with
  62     <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.  The
  63     container names are resolved to the IP addresses of the specific container, ordered by their scope. This
  64     functionality only applies to containers using network namespacing.</para>
  65
  66     <para>The module also resolves user and group IDs used by containers to user and group names indicating the
  67     container name, and back. This functionality only applies to containers using user namespacing.</para>
  68
  69     <para>To activate the NSS module, add <literal>mymachines</literal> to the lines starting with
  70     <literal>hosts:</literal>, <literal>passwd:</literal> and <literal>group:</literal> in
  71     <filename>/etc/nsswitch.conf</filename>.</para>
  72
  73     <para>It is recommended to place <literal>mymachines</literal> after the <literal>files</literal> or
  74     <literal>compat</literal> entry of the <filename>/etc/nsswitch.conf</filename> lines to make sure that its mappings
  75     are preferred over other resolvers such as DNS, but so that <filename>/etc/hosts</filename>,
  76     <filename>/etc/passwd</filename> and <filename>/etc/group</filename> based mappings take precedence.</para>
  77   </refsect1>
  78
  79   <refsect1>
  80     <title>Example</title>
  81
  82     <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables
  83     <command>nss-mymachines</command> correctly:</para>
  84
  85     <programlisting>passwd:         compat <command>mymachines</command>
  86 group:          compat <command>mymachines</command>
  87 shadow:         compat
  88
  89 hosts:          files <command>mymachines</command> resolve myhostname
  90 networks:       files
  91
  92 protocols:      db files
  93 services:       db files
  94 ethers:         db files
  95 rpc:            db files
  96
  97 netgroup:       nis</programlisting>
  98
  99   </refsect1>
 100
 101   <refsect1>
 102     <title>See Also</title>
 103     <para>
 104       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 105       <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 106       <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 107       <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 108       <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 109       <citerefentry project='man-pages'><refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 110     </para>
 111   </refsect1>
 112
 113 </refentry>