<?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 2013 David Strauss 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="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>