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include <poll.h> instead of <sys/poll.h>
[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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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>