summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLennart Poettering <lennart@poettering.net>2015-01-07 17:14:04 +0100
committerLennart Poettering <lennart@poettering.net>2015-01-07 17:14:04 +0100
commitb311d32ff4fac5335aa8eea479bda49131ecae75 (patch)
treeaffc87713c30bac70ee00e19c533814f2b157736
parent5b728e6ba17c39e0787ad81b96a5582f4390f091 (diff)
man: rework nss-myhostname man page
Remove a number of incorrect links, and explain that "localhost" and "gateway" are now resolved by it, too.
-rw-r--r--man/nss-myhostname.xml99
1 files changed, 63 insertions, 36 deletions
diff --git a/man/nss-myhostname.xml b/man/nss-myhostname.xml
index ba9297ec79..999d1afaf5 100644
--- a/man/nss-myhostname.xml
+++ b/man/nss-myhostname.xml
@@ -50,49 +50,81 @@
</refnamediv>
<refsynopsisdiv>
- <para><filename>nss-myhostname.la</filename></para>
+ <para><filename>libnss_myhostname.so.2</filename></para>
</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 hostname 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 hostname. 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 configured public IP addresses, or, if none
- are configured, the IPv4 address 127.0.0.2 (which 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>
+ <para><command>nss-myhostname</command> is a plugin
+ for the GNU Name Service Switch (NSS) functionality of
+ the GNU C Library (<command>glibc</command>) primarily
+ providing hostname resolution for the locally
+ configured system hostname as returned by
+ <citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>. The
+ precise hostnames resolved by this module are:</para>
+
+ <itemizedlist>
+ <listitem><para>The local, configured hostname
+ is resolved to all locally configured public
+ IP addresses, or -- if none are configured --
+ the IPv4 address 127.0.0.2 (which is on the
+ local loopback) and the IPv6 address ::1
+ (which is the local host).</para></listitem>
+
+ <listitem><para>The hostname
+ <literal>localhost</literal> is resolved to
+ the IP addresses 127.0.0.1 and
+ ::1.</para></listitem>
+
+ <listitem><para>The hostname
+ <literal>gateway</literal> is resolved to all
+ current default routing gateway addresses,
+ ordered by their metric. This assigns a stable
+ hostname to the current gateway, useful for
+ referencing it independently of the current
+ network configuration state.</para></listitem>
+
+ </itemizedlist>
+
+ <para>Various software relies on an always-resolvable
+ local hostname. When using dynamic hostnames, this is
+ traditionally achieved by patching
+ <filename>/etc/hosts</filename> at the same time as
+ changing the hostname. This is problematic 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. With
+ <command>nss-myhostname</command> enabled changing
+ <filename>/etc/hosts</filename> is unncessary, and on
+ many systems the file becomes entirely optional.</para>
+
+ <para>To activate the NSS modules,
+ <literal>myhostname</literal> has to be added to the
+ line starting with <literal>hosts:</literal> in
+ <filename>/etc/nsswitch.conf</filename>.</para>
+
+ <para>It is recommended to place
+ <literal>myhostname</literal> 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
+ <para>Here's an example
+ <filename>/etc/nsswitch.conf</filename> file, that
+ enables <command>myhostname</command>
+ correctly:</para>
-passwd: compat
+<programlisting>passwd: compat
group: compat
shadow: compat
-hosts: files dns <varname>myhostname</varname>
+hosts: files dns <command>myhostname</command>
networks: files
protocols: db files
@@ -120,13 +152,8 @@ netgroup: nis</programlisting>
<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 project='man-pages'><refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry project='die-net'><refentrytitle>pam_loginuid</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>