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journald: move /dev/log socket to /run
[elogind.git] / man / systemd-socket-proxyd.xml
1 <?xml version="1.0"?>
2 <!--*-nxml-*-->
3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4      "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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8   Copyright 2013 David Strauss
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22 -->
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>