networkd-wait-online: improve interoptability and enable by default
To make sure we don't delay boot on systems where (some) network links are managed by someone else
we don't block if something else has successfully brought up a link.
We will still block until all links we are aware of that are managed by networkd have been
configured, but if no such links exist, and someone else have configured a link sufficiently
that it has a carrier, it may be that the link is ready so we should no longer block.
Note that in all likelyhood the link is not ready (no addresses/routes configured),
so whatever network managment daemon configured it should provide a similar wait-online
service to block network-online.target until it is ready.
The aim is to block as long as we know networking is not fully configured, but no longer. This
will allow systemd-networkd-wait-online.service to be enabled on any system, even if we don't
know whether networkd is the main/only network manager.
Even in the case networking is fully configured by networkd, the default behavior may not be
sufficient: if two links need to be configured, but the first is fully configured before the
second one appears we will assume the network is up. To work around that, we allow specifying
specific devices to wait for before considering the network up.
This unit is enabled by default, just like systemd-networkd, but will only be pulled in if
anyone pulls in network-online.target.
2014-04-23 19:42:55 +04:00
<?xml version='1.0'?> <!-- * - nxml - * -->
< !DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
2015-06-18 20:47:44 +03:00
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
networkd-wait-online: improve interoptability and enable by default
To make sure we don't delay boot on systems where (some) network links are managed by someone else
we don't block if something else has successfully brought up a link.
We will still block until all links we are aware of that are managed by networkd have been
configured, but if no such links exist, and someone else have configured a link sufficiently
that it has a carrier, it may be that the link is ready so we should no longer block.
Note that in all likelyhood the link is not ready (no addresses/routes configured),
so whatever network managment daemon configured it should provide a similar wait-online
service to block network-online.target until it is ready.
The aim is to block as long as we know networking is not fully configured, but no longer. This
will allow systemd-networkd-wait-online.service to be enabled on any system, even if we don't
know whether networkd is the main/only network manager.
Even in the case networking is fully configured by networkd, the default behavior may not be
sufficient: if two links need to be configured, but the first is fully configured before the
second one appears we will assume the network is up. To work around that, we allow specifying
specific devices to wait for before considering the network up.
This unit is enabled by default, just like systemd-networkd, but will only be pulled in if
anyone pulls in network-online.target.
2014-04-23 19:42:55 +04:00
<!--
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Copyright 2014 Tom Gundersen
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systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
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You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http: / / w w w . g n u . o r g / l i c e n s e s /> .
-->
<refentry id= "systemd-networkd-wait-online.service" conditional= 'ENABLE_NETWORKD' >
2015-02-04 05:14:13 +03:00
<refentryinfo >
<title > systemd-networkd.service</title>
<productname > systemd</productname>
<authorgroup >
<author >
<contrib > Developer</contrib>
<firstname > Tom</firstname>
<surname > Gundersen</surname>
<email > teg@jklm.no</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta >
<refentrytitle > systemd-networkd-wait-online.service</refentrytitle>
<manvolnum > 8</manvolnum>
</refmeta>
<refnamediv >
<refname > systemd-networkd-wait-online.service</refname>
<refname > systemd-networkd-wait-online</refname>
<refpurpose > Wait for network to come online</refpurpose>
</refnamediv>
<refsynopsisdiv >
<para > <filename > systemd-networkd-wait-online.service</filename> </para>
2015-06-18 20:47:44 +03:00
<para > <filename > /usr/lib/systemd/systemd-networkd-wait-online</filename> </para>
2015-02-04 05:14:13 +03:00
</refsynopsisdiv>
<refsect1 >
<title > Description</title>
<para > <command > systemd-networkd-wait-online</command> is a
one-shot system service that waits for the network to be
configured. By default, it will wait for all links it is aware of
and which are managed by
<citerefentry > <refentrytitle > systemd-networkd.service</refentrytitle> <manvolnum > 8</manvolnum> </citerefentry>
to be fully configured or failed, and for at least one link to
gain a carrier.</para>
</refsect1>
<refsect1 >
<title > Options</title>
<para > The following options are understood:</para>
<variablelist >
<varlistentry >
<term > <option > -i</option> </term>
<term > <option > --interface=</option> </term>
<listitem > <para > Network interface to wait for before deciding
if the system is online. This is useful when a system has
several interfaces which will be configured, but a particular
one is necessary to access some network resources. This option
may be used more than once to wait for multiple network
interfaces.</para> </listitem>
</varlistentry>
<varlistentry >
<term > <option > --ignore=</option> </term>
<listitem > <para > Network interfaces to be ignored when deciding
if the system is online. By default only the loopback
interface is ignored. This option may be used more than once
to ignore multiple network interfaces. </para> </listitem>
</varlistentry>
<varlistentry >
<term > <option > --timeout=</option> </term>
<listitem > <para > Fail the service if the network is not online
by the time the timeout elapses. A timeout of 0 disables the
timeout. Defaults to 120 seconds. </para> </listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 >
<title > See Also</title>
<para >
<citerefentry > <refentrytitle > systemd</refentrytitle> <manvolnum > 1</manvolnum> </citerefentry> ,
<citerefentry > <refentrytitle > systemd-networkd.service</refentrytitle> <manvolnum > 8</manvolnum> </citerefentry>
</para>
</refsect1>
networkd-wait-online: improve interoptability and enable by default
To make sure we don't delay boot on systems where (some) network links are managed by someone else
we don't block if something else has successfully brought up a link.
We will still block until all links we are aware of that are managed by networkd have been
configured, but if no such links exist, and someone else have configured a link sufficiently
that it has a carrier, it may be that the link is ready so we should no longer block.
Note that in all likelyhood the link is not ready (no addresses/routes configured),
so whatever network managment daemon configured it should provide a similar wait-online
service to block network-online.target until it is ready.
The aim is to block as long as we know networking is not fully configured, but no longer. This
will allow systemd-networkd-wait-online.service to be enabled on any system, even if we don't
know whether networkd is the main/only network manager.
Even in the case networking is fully configured by networkd, the default behavior may not be
sufficient: if two links need to be configured, but the first is fully configured before the
second one appears we will assume the network is up. To work around that, we allow specifying
specific devices to wait for before considering the network up.
This unit is enabled by default, just like systemd-networkd, but will only be pulled in if
anyone pulls in network-online.target.
2014-04-23 19:42:55 +04:00
</refentry>