diff options
Diffstat (limited to 'man/nss-myhostname.xml')
| -rw-r--r-- | man/nss-myhostname.xml | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/man/nss-myhostname.xml b/man/nss-myhostname.xml new file mode 100644 index 0000000000..bd3f635692 --- /dev/null +++ b/man/nss-myhostname.xml @@ -0,0 +1,139 @@ +<?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"> + +<!-- + This file is part of systemd. + + Copyright 2011 Lennart Poettering + Copyright 2013 Tom Gundersen + + 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-myhostname"> + + <refentryinfo> + <title>nss-myhostname</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-myhostname</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>nss-myhostname</refname> + <refpurpose>Provide host name resolution for the locally + configured system hostname.</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>nss-myhostname.la</command> + </cmdsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>nss-myhostname</command> is a plugin for the GNU Name Service Switch + (NSS) functionality of the GNU C Library (<command>glibc</command>) + providing host name resolution for the locally configured system + hostname as returned by + <citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>. + Various software relies on an always resolvable local host name. When + using dynamic hostnames this is usually achieved by patching + <filename>/etc/hosts</filename> at the same time as changing the host + name. This however is not ideal since it requires a writable + <filename>/etc</filename> file system and is fragile because the file + might be edited by the administrator at the same time. <command>nss-myhostname</command> + simply returns all locally configure public IP addresses, or -- if none + are configured -- the IPv4 address 127.0.0.2 (wich is on the local + loopback) and the IPv6 address ::1 (which is the local host) for + whatever system hostname is configured locally. Patching + <filename>/etc/hosts</filename> is thus no longer necessary.</para> + + <para>To activate the NSS modules, <option>myhostname</option> + has to be added to the line starting with "<varname>hosts:</varname>" in + <filename>/etc/nsswitch.conf</filename></para> + + <para>It is recommended to put <option>myhostname</option> + last in the <filename>nsswitch.conf</filename> line to make + sure that this mapping is only used as fallback, and any DNS + or <filename>/etc/hosts</filename> based mapping takes precedence.</para> + </refsect1> + + <refsect1> + <title>Example</title> + + <programlisting> +# /etc/nsswitch.conf + +passwd: compat +group: compat +shadow: compat + +hosts: files dns <varname>myhostname</varname> +networks: files + +protocols: db files +services: db files +ethers: db files +rpc: db files + +netgroup: nis + </programlisting> + + <para>To test, use <command>glibc</command>'s <command>getent</command> tool:</para> + + <programlisting> +$ getent ahosts `hostname` +::1 STREAM omega +::1 DGRAM +::1 RAW +127.0.0.2 STREAM +127.0.0.2 DGRAM +127.0.0.2 RAW + </programlisting> + + <para>In this case the local host name is <varname>omega</varname>.</para> + + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>pam_loginuid</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |