man/systemd-socket-proxyd.xml

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   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   8   Copyright 2013 David Strauss
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  23 <refentry id="systemd-socket-proxyd"
  24     xmlns:xi="http://www.w3.org/2001/XInclude">
  25
  26   <refentryinfo>
  27     <title>systemd-socket-proxyd</title>
  28     <productname>systemd</productname>
  29     <authorgroup>
  30       <author>
  31         <contrib>Developer</contrib>
  32         <firstname>David</firstname>
  33         <surname>Strauss</surname>
  34         <email>david@davidstrauss.net</email>
  35       </author>
  36     </authorgroup>
  37   </refentryinfo>
  38   <refmeta>
  39     <refentrytitle>systemd-socket-proxyd</refentrytitle>
  40     <manvolnum>8</manvolnum>
  41   </refmeta>
  42   <refnamediv>
  43     <refname>systemd-socket-proxyd</refname>
  44     <refpurpose>Bidirectionally proxy local sockets to another (possibly remote) socket.</refpurpose>
  45   </refnamediv>
  46   <refsynopsisdiv>
  47     <cmdsynopsis>
  48       <command>systemd-socket-proxyd</command>
  49       <arg choice="opt" rep="repeat"><replaceable>OPTIONS</replaceable></arg>
  50       <arg choice="plain"><replaceable>HOST</replaceable>:<replaceable>PORT</replaceable></arg>
  51     </cmdsynopsis>
  52     <cmdsynopsis>
  53       <command>systemd-socket-proxyd</command>
  54       <arg choice="opt" rep="repeat"><replaceable>OPTIONS</replaceable></arg>
  55       <arg choice="plain"><replaceable>UNIX-DOMAIN-SOCKET-PATH</replaceable>
  56       </arg>
  57     </cmdsynopsis>
  58   </refsynopsisdiv>
  59   <refsect1>
  60     <title>Description</title>
  61     <para>
  62     <command>systemd-socket-proxyd</command> is a generic
  63     socket-activated network socket forwarder proxy daemon for IPv4,
  64     IPv6 and UNIX stream sockets. It may be used to bi-directionally
  65     forward traffic from a local listening socket to a local or remote
  66     destination socket.</para>
  67
  68     <para>One use of this tool is to provide socket activation support
  69     for services that do not natively support socket activation. On
  70     behalf of the service to activate, the proxy inherits the socket
  71     from systemd, accepts each client connection, opens a connection
  72     to a configured server for each client, and then bidirectionally
  73     forwards data between the two.</para>
  74     <para>This utility's behavior is similar to
  75     <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
  76     The main differences for <command>systemd-socket-proxyd</command>
  77     are support for socket activation with
  78     <literal>Accept=false</literal> and an event-driven
  79     design that scales better with the number of
  80     connections.</para>
  81   </refsect1>
  82   <refsect1>
  83     <title>Options</title>
  84     <para>The following options are understood:</para>
  85     <variablelist>
  86       <xi:include href="standard-options.xml" xpointer="help" />
  87       <xi:include href="standard-options.xml" xpointer="version" />
  88     </variablelist>
  89   </refsect1>
  90   <refsect1>
  91     <title>Exit status</title>
  92     <para>On success, 0 is returned, a non-zero failure
  93     code otherwise.</para>
  94   </refsect1>
  95   <refsect1>
  96     <title>Examples</title>
  97     <refsect2>
  98       <title>Simple Example</title>
  99       <para>Use two services with a dependency and no namespace
 100       isolation.</para>
 101       <example>
 102         <title>proxy-to-nginx.socket</title>
 103         <programlisting><![CDATA[[Socket]
 104 ListenStream=80
 105
 106 [Install]
 107 WantedBy=sockets.target]]></programlisting>
 108       </example>
 109       <example>
 110         <title>proxy-to-nginx.service</title>
 111         <programlisting><![CDATA[[Unit]
 112 Requires=nginx.service
 113 After=nginx.service
 114
 115 [Service]
 116 ExecStart=/usr/lib/systemd/systemd-socket-proxyd /tmp/nginx.sock
 117 PrivateTmp=yes
 118 PrivateNetwork=yes]]></programlisting>
 119       </example>
 120       <example>
 121         <title>nginx.conf</title>
 122         <programlisting>
 123 <![CDATA[[...]
 124 server {
 125     listen       unix:/tmp/nginx.sock;
 126     [...]]]>
 127 </programlisting>
 128       </example>
 129       <example>
 130         <title>Enabling the proxy</title>
 131         <programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
 132 # systemctl start proxy-to-nginx.socket
 133 $ curl http://localhost:80/]]></programlisting>
 134       </example>
 135     </refsect2>
 136     <refsect2>
 137       <title>Namespace Example</title>
 138       <para>Similar as above, but runs the socket proxy and the main
 139       service in the same private namespace, assuming that
 140       <filename>nginx.service</filename> has
 141       <varname>PrivateTmp=</varname> and
 142       <varname>PrivateNetwork=</varname> set, too.</para>
 143       <example>
 144         <title>proxy-to-nginx.socket</title>
 145         <programlisting><![CDATA[[Socket]
 146 ListenStream=80
 147
 148 [Install]
 149 WantedBy=sockets.target]]></programlisting>
 150       </example>
 151       <example>
 152         <title>proxy-to-nginx.service</title>
 153         <programlisting><![CDATA[[Unit]
 154 Requires=nginx.service
 155 After=nginx.service
 156 JoinsNamespaceOf=nginx.service
 157
 158 [Service]
 159 ExecStart=/usr/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
 160 PrivateTmp=yes
 161 PrivateNetwork=yes]]></programlisting>
 162       </example>
 163       <example>
 164         <title>nginx.conf</title>
 165         <programlisting><![CDATA[[...]
 166 server {
 167     listen       8080;
 168     listen       unix:/tmp/nginx.sock;
 169     [...]]]></programlisting>
 170       </example>
 171       <example>
 172         <title>Enabling the proxy</title>
 173         <programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
 174 # systemctl start proxy-to-nginx.socket
 175 $ curl http://localhost:80/]]></programlisting>
 176       </example>
 177     </refsect2>
 178   </refsect1>
 179   <refsect1>
 180     <title>See Also</title>
 181     <para>
 182       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 183       <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 184       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 185       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 186       <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 187       <citerefentry><refentrytitle>nginx</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 188       <citerefentry><refentrytitle>curl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 189     </para>
 190   </refsect1>
 191 </refentry>