X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fnss-myhostname.xml;h=c7a2cd9ae7b4edf90732a0036656199d095757b7;hp=bd3f635692246903ed6b293dc4bf2ff47a5c550c;hb=79b1f37d95f08fe7620b071eec51d2810ed077c9;hpb=16eb4da97e1bfe7f9416a0622b1a06408e550423

diff --git a/man/nss-myhostname.xml b/man/nss-myhostname.xml
index bd3f63569..c7a2cd9ae 100644
--- a/man/nss-myhostname.xml
+++ b/man/nss-myhostname.xml
@@ -22,7 +22,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 
-<refentry id="nss-myhostname">
+<refentry id="nss-myhostname" conditional='HAVE_MYHOSTNAME'>
 
         <refentryinfo>
                 <title>nss-myhostname</title>
@@ -45,57 +45,88 @@
 
         <refnamediv>
                 <refname>nss-myhostname</refname>
-                <refpurpose>Provide host name resolution for the locally
+                <refname>libnss_myhostname.so.2</refname>
+                <refpurpose>Provide hostname resolution for the locally
                 configured system hostname.</refpurpose>
         </refnamediv>
 
         <refsynopsisdiv>
-                <cmdsynopsis>
-                        <command>nss-myhostname.la</command>
-                </cmdsynopsis>
+                <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 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>
+                <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 IP
+                        addresses ordered by their scope, 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 mymachines <command>myhostname</command>
 networks:       files
 
 protocols:      db files
@@ -103,22 +134,19 @@ services:       db files
 ethers:         db files
 rpc:            db files
 
-netgroup:       nis
-                </programlisting>
+netgroup:       nis</programlisting>
 
                 <para>To test, use <command>glibc</command>'s <command>getent</command> tool:</para>
 
-                <programlisting>
-$ getent ahosts `hostname`
+                <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>
+127.0.0.2       RAW</programlisting>
 
-                <para>In this case the local host name is <varname>omega</varname>.</para>
+                <para>In this case the local hostname is <varname>omega</varname>.</para>
 
         </refsect1>
 
@@ -126,13 +154,9 @@ $ getent ahosts `hostname`
                 <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>
+                        <citerefentry><refentrytitle>nss-mymachines</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>