systemd/man/systemd-socket-proxyd.xml
Tom Gundersen 12b42c7667 man: revert dynamic paths for split-usr setups
This did not really work out as we had hoped. Trying to do this upstream
introduced several problems that probably makes it better suited as a
downstream patch after all. At any rate, it is not releaseable in the
current state, so we at least need to revert this before the release.

 * by adjusting the path to binaries, but not do the same thing to the
   search path we end up with inconsistent man-pages. Adjusting the search
   path too would be quite messy, and it is not at all obvious that this is
   worth the effort, but at any rate it would have to be done before we
   could ship this.

 * this means that distributed man-pages does not make sense as they depend
   on config options, and for better or worse we are still distributing
   man pages, so that is something that definitely needs sorting out before
   we could ship with this patch.

 * we have long held that split-usr is only minimally supported in order
   to boot, and something we hope will eventually go away. So before we start
   adding even more magic/effort in order to make this work nicely, we should
   probably question if it makes sense at all.
2015-06-18 19:47:44 +02:00

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<?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">
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<refentry id="systemd-socket-proxyd"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>systemd-socket-proxyd</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>David</firstname>
<surname>Strauss</surname>
<email>david@davidstrauss.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-socket-proxyd</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-socket-proxyd</refname>
<refpurpose>Bidirectionally proxy local sockets to another (possibly remote) socket.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemd-socket-proxyd</command>
<arg choice="opt" rep="repeat"><replaceable>OPTIONS</replaceable></arg>
<arg choice="plain"><replaceable>HOST</replaceable>:<replaceable>PORT</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-socket-proxyd</command>
<arg choice="opt" rep="repeat"><replaceable>OPTIONS</replaceable></arg>
<arg choice="plain"><replaceable>UNIX-DOMAIN-SOCKET-PATH</replaceable>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>systemd-socket-proxyd</command> is a generic
socket-activated network socket forwarder proxy daemon for IPv4,
IPv6 and UNIX stream sockets. It may be used to bi-directionally
forward traffic from a local listening socket to a local or remote
destination socket.</para>
<para>One use of this tool is to provide socket activation support
for services that do not natively support socket activation. On
behalf of the service to activate, the proxy inherits the socket
from systemd, accepts each client connection, opens a connection
to a configured server for each client, and then bidirectionally
forwards data between the two.</para>
<para>This utility's behavior is similar to
<citerefentry project='die-net'><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
The main differences for <command>systemd-socket-proxyd</command>
are support for socket activation with
<literal>Accept=false</literal> and an event-driven
design that scales better with the number of
connections.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<xi:include href="standard-options.xml" xpointer="help" />
<xi:include href="standard-options.xml" xpointer="version" />
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success, 0 is returned, a non-zero failure
code otherwise.</para>
</refsect1>
<refsect1>
<title>Examples</title>
<refsect2>
<title>Simple Example</title>
<para>Use two services with a dependency and no namespace
isolation.</para>
<example>
<title>proxy-to-nginx.socket</title>
<programlisting><![CDATA[[Socket]
ListenStream=80
[Install]
WantedBy=sockets.target]]></programlisting>
</example>
<example>
<title>proxy-to-nginx.service</title>
<programlisting><![CDATA[[Unit]
Requires=nginx.service
After=nginx.service
[Service]
ExecStart=/usr/lib/systemd/systemd-socket-proxyd /tmp/nginx.sock
PrivateTmp=yes
PrivateNetwork=yes]]></programlisting>
</example>
<example>
<title>nginx.conf</title>
<programlisting>
<![CDATA[[...]
server {
listen unix:/tmp/nginx.sock;
[...]]]>
</programlisting>
</example>
<example>
<title>Enabling the proxy</title>
<programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
# systemctl start proxy-to-nginx.socket
$ curl http://localhost:80/]]></programlisting>
</example>
</refsect2>
<refsect2>
<title>Namespace Example</title>
<para>Similar as above, but runs the socket proxy and the main
service in the same private namespace, assuming that
<filename>nginx.service</filename> has
<varname>PrivateTmp=</varname> and
<varname>PrivateNetwork=</varname> set, too.</para>
<example>
<title>proxy-to-nginx.socket</title>
<programlisting><![CDATA[[Socket]
ListenStream=80
[Install]
WantedBy=sockets.target]]></programlisting>
</example>
<example>
<title>proxy-to-nginx.service</title>
<programlisting><![CDATA[[Unit]
Requires=nginx.service
After=nginx.service
JoinsNamespaceOf=nginx.service
[Service]
ExecStart=/usr/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
PrivateTmp=yes
PrivateNetwork=yes]]></programlisting>
</example>
<example>
<title>nginx.conf</title>
<programlisting><![CDATA[[...]
server {
listen 8080;
[...]]]></programlisting>
</example>
<example>
<title>Enabling the proxy</title>
<programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
# systemctl start proxy-to-nginx.socket
$ curl http://localhost:80/]]></programlisting>
</example>
</refsect2>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry project='die-net'><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry project='die-net'><refentrytitle>nginx</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry project='die-net'><refentrytitle>curl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>