man/systemd-socket-proxyd.xml

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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
  64                 for IPv4, IPv6 and UNIX stream sockets. It may be used
  65                 to bi-directionally forward traffic from a local listening socket to a
  66                 local or remote destination socket.</para>
  67
  68                 <para>One use of this tool is to provide
  69                 socket activation support for services that do not
  70                 natively support socket activation. On behalf of the
  71                 service to activate, the proxy inherits the socket
  72                 from systemd, accepts each client connection, opens a
  73                 connection to a configured server for each client, and
  74                 then bidirectionally forwards data between the
  75                 two.</para>
  76                 <para>This utility's behavior is similar to
  77                 <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
  78                 The main differences for <command>systemd-socket-proxyd</command>
  79                 are support for socket activation with
  80                 <literal>Accept=false</literal> and an event-driven
  81                 design that scales better with the number of
  82                 connections.</para>
  83         </refsect1>
  84         <refsect1>
  85                 <title>Options</title>
  86                 <para>The following options are understood:</para>
  87                 <variablelist>
  88                         <xi:include href="standard-options.xml" xpointer="help" />
  89                         <xi:include href="standard-options.xml" xpointer="version" />
  90                 </variablelist>
  91         </refsect1>
  92         <refsect1>
  93                 <title>Exit status</title>
  94                 <para>On success, 0 is returned, a non-zero failure
  95                 code otherwise.</para>
  96         </refsect1>
  97         <refsect1>
  98                 <title>Examples</title>
  99                 <refsect2>
 100                         <title>Simple Example</title>
 101                         <para>Use two services with a dependency
 102                         and no namespace isolation.</para>
 103                         <example>
 104                                 <title>proxy-to-nginx.socket</title>
 105                                 <programlisting><![CDATA[[Socket]
 106 ListenStream=80
 107
 108 [Install]
 109 WantedBy=sockets.target]]></programlisting>
 110                         </example>
 111                         <example>
 112                                 <title>proxy-to-nginx.service</title>
 113                                 <programlisting><![CDATA[[Unit]
 114 Requires=nginx.service
 115 After=nginx.service
 116
 117 [Service]
 118 ExecStart=/usr/lib/systemd/systemd-socket-proxyd /tmp/nginx.sock
 119 PrivateTmp=yes
 120 PrivateNetwork=yes]]></programlisting>
 121                         </example>
 122                         <example>
 123                                 <title>nginx.conf</title>
 124                                 <programlisting>
 125 <![CDATA[[...]
 126 server {
 127     listen       unix:/tmp/nginx.sock;
 128     [...]]]>
 129 </programlisting>
 130                         </example>
 131                         <example>
 132                                 <title>Enabling the proxy</title>
 133                                 <programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
 134 # systemctl start proxy-to-nginx.socket
 135 $ curl http://localhost:80/]]></programlisting>
 136                         </example>
 137                 </refsect2>
 138                 <refsect2>
 139                         <title>Namespace Example</title>
 140                         <para>Similar as above, but runs the socket
 141                         proxy and the main service in the same private
 142                         namespace, assuming that
 143                         <filename>nginx.service</filename> has
 144                         <varname>PrivateTmp=</varname> and
 145                         <varname>PrivateNetwork=</varname> set,
 146                         too.</para>
 147                         <example>
 148                                 <title>proxy-to-nginx.socket</title>
 149                                 <programlisting><![CDATA[[Socket]
 150 ListenStream=80
 151
 152 [Install]
 153 WantedBy=sockets.target]]></programlisting>
 154                         </example>
 155                         <example>
 156                                 <title>proxy-to-nginx.service</title>
 157                                 <programlisting><![CDATA[[Unit]
 158 Requires=nginx.service
 159 After=nginx.service
 160 JoinsNamespaceOf=nginx.service
 161
 162 [Service]
 163 ExecStart=/usr/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
 164 PrivateTmp=yes
 165 PrivateNetwork=yes]]></programlisting>
 166                         </example>
 167                         <example>
 168                                 <title>nginx.conf</title>
 169                                 <programlisting><![CDATA[[...]
 170 server {
 171     listen       8080;
 172     listen       unix:/tmp/nginx.sock;
 173     [...]]]></programlisting>
 174                         </example>
 175                         <example>
 176                                 <title>Enabling the proxy</title>
 177                                 <programlisting><![CDATA[# systemctl enable proxy-to-nginx.socket
 178 # systemctl start proxy-to-nginx.socket
 179 $ curl http://localhost:80/]]></programlisting>
 180                         </example>
 181                 </refsect2>
 182         </refsect1>
 183         <refsect1>
 184                 <title>See Also</title>
 185                 <para>
 186                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 187                         <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 188                         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 189                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 190                         <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 191                         <citerefentry><refentrytitle>nginx</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 192                         <citerefentry><refentrytitle>curl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 193                 </para>
 194         </refsect1>
 195 </refentry>