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         <refentryinfo>
  25                 <title>systemd-socket-proxyd</title>
  26                 <productname>systemd</productname>
  27                 <authorgroup>
  28                         <author>
  29                                 <contrib>Developer</contrib>
  30                                 <firstname>David</firstname>
  31                                 <surname>Strauss</surname>
  32                                 <email>david@davidstrauss.net</email>
  33                         </author>
  34                 </authorgroup>
  35         </refentryinfo>
  36         <refmeta>
  37                 <refentrytitle>systemd-socket-proxyd</refentrytitle>
  38                 <manvolnum>1</manvolnum>
  39         </refmeta>
  40         <refnamediv>
  41                 <refname>systemd-socket-proxyd</refname>
  42                 <refpurpose>Inherit a socket. Bidirectionally
  43                 proxy.</refpurpose>
  44         </refnamediv>
  45         <refsynopsisdiv>
  46                 <cmdsynopsis>
  47                         <command>systemd-socket-proxyd</command>
  48                         <arg choice="opt" rep="repeat">OPTIONS</arg>
  49                         <arg choice="plain"><replaceable>HOSTNAME-OR-IPADDR</replaceable></arg>
  50                         <arg choice="plain"><replaceable>PORT-OR-SERVICE</replaceable></arg>
  51                 </cmdsynopsis>
  52                 <cmdsynopsis>
  53                         <command>systemd-socket-proxyd</command>
  54                         <arg choice="opt" rep="repeat">OPTIONS</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> provides a proxy
  63                 to socket-activate services that do not yet support
  64                 native socket activation. On behalf of the daemon,
  65                 the proxy inherits the socket from systemd, accepts
  66                 each client connection, opens a connection to the server
  67                 for each client, and then bidirectionally forwards
  68                 data between the two.</para>
  69                 <para>This utility's behavior is similar to
  70                 <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
  71                 The main differences for <command>systemd-socket-proxyd</command>
  72                 are support for socket activation with
  73                 <literal>Accept=false</literal> and an event-driven
  74                 design that scales better with the number of
  75                 connections.</para>
  76         </refsect1>
  77         <refsect1>
  78                 <title>Options</title>
  79                 <para>The following options are understood:</para>
  80                 <variablelist>
  81                         <varlistentry>
  82                                 <term><option>-h</option></term>
  83                                 <term><option>--help</option></term>
  84                                 <listitem>
  85                                         <para>Prints a short help
  86                                         text and exits.</para>
  87                                 </listitem>
  88                         </varlistentry>
  89                         <varlistentry>
  90                                 <term><option>--version</option></term>
  91                                 <listitem>
  92                                         <para>Prints a version
  93                                         string and exits.</para>
  94                                 </listitem>
  95                         </varlistentry>
  96                         <varlistentry>
  97                                 <term><option>--ignore-env</option></term>
  98                                 <listitem>
  99                                         <para>Skips verification of
 100                                         the expected PID and file
 101                                         descriptor numbers. Use this if
 102                                         invoked indirectly, for
 103                                         example, with a shell script
 104                                         rather than with
 105                                         <option>ExecStart=/usr/lib/systemd/systemd-socket-proxyd</option>
 106                                         </para>
 107                                 </listitem>
 108                         </varlistentry>
 109                 </variablelist>
 110         </refsect1>
 111         <refsect1>
 112                 <title>Exit status</title>
 113                 <para>On success, 0 is returned, a non-zero failure
 114                 code otherwise.</para>
 115         </refsect1>
 116         <refsect1>
 117                 <title>Examples</title>
 118                 <refsect2>
 119                         <title>Direct-Use Example</title>
 120                         <para>Use two services with a dependency
 121                         and no namespace isolation.</para>
 122                         <example label="proxy socket unit">
 123                                 <title>/etc/systemd/system/proxy-to-nginx.socket</title>
 124                                 <programlisting>
 125 <![CDATA[[Socket]
 126 ListenStream=80
 127
 128 [Install]
 129 WantedBy=sockets.target]]>
 130 </programlisting>
 131                         </example>
 132                         <example label="proxy service unit">
 133                                 <title>/etc/systemd/system/proxy-to-nginx.service</title>
 134                                 <programlisting>
 135 <![CDATA[[Unit]
 136 After=nginx.service
 137 Requires=nginx.service
 138
 139 [Service]
 140 ExecStart=/usr/bin/systemd-socket-proxyd /tmp/nginx.sock
 141 PrivateTmp=true
 142 PrivateNetwork=true]]>
 143 </programlisting>
 144                         </example>
 145                         <example label="nginx configuration">
 146                                 <title>/etc/nginx/nginx.conf</title>
 147                                 <programlisting>
 148 <![CDATA[[...]
 149 server {
 150     listen       unix:/tmp/nginx.sock;
 151     [...]]]>
 152 </programlisting>
 153                         </example>
 154                         <example label="commands">
 155                                 <programlisting>
 156 <![CDATA[$ sudo systemctl --system daemon-reload
 157 $ sudo systemctl start proxy-to-nginx.socket
 158 $ sudo systemctl enable proxy-to-nginx.socket
 159 $ curl http://localhost:80/]]>
 160 </programlisting>
 161                         </example>
 162                 </refsect2>
 163                 <refsect2>
 164                         <title>Indirect-Use Example</title>
 165                         <para>Use a shell script to isolate the
 166                         service and proxy into the same namespace.
 167                         This is particularly useful for running
 168                         TCP-only daemons without the daemon
 169                         affecting ports on regular
 170                         interfaces.</para>
 171                         <example label="combined proxy and nginx socket unit">
 172
 173                                 <title>
 174                                 /etc/systemd/system/proxy-with-nginx.socket</title>
 175                                 <programlisting>
 176 <![CDATA[[Socket]
 177 ListenStream=80
 178
 179 [Install]
 180 WantedBy=sockets.target]]>
 181 </programlisting>
 182                         </example>
 183                         <example label="combined proxy and nginx service unit">
 184
 185                                 <title>
 186                                 /etc/systemd/system/proxy-with-nginx.service</title>
 187                                 <programlisting>
 188 <![CDATA[[Unit]
 189 After=syslog.target remote-fs.target nss-lookup.target
 190
 191 [Service]
 192 ExecStartPre=/usr/sbin/nginx -t
 193 ExecStart=/usr/bin/socket-proxyd-nginx.sh
 194 PrivateTmp=true
 195 PrivateNetwork=true]]>
 196 </programlisting>
 197                         </example>
 198                         <example label="shell script">
 199                                 <title>
 200                                 /usr/bin/socket-proxyd-nginx.sh</title>
 201                                 <programlisting>
 202 <![CDATA[#!/bin/sh
 203 /usr/sbin/nginx
 204 while [ ! -f /tmp/nginx.pid ]
 205   do
 206      /usr/bin/inotifywait /tmp/nginx.pid
 207   done
 208 /usr/bin/systemd-socket-proxyd --ignore-env localhost 8080]]>
 209 </programlisting>
 210                         </example>
 211                         <example label="nginx configuration">
 212                                 <title>
 213                                 /etc/nginx/nginx.conf</title>
 214                                 <programlisting>
 215 <![CDATA[[...]
 216 server {
 217     listen       8080;
 218     listen       unix:/tmp/nginx.sock;
 219     [...]]]>
 220 </programlisting>
 221                         </example>
 222                         <example label="commands">
 223                                 <programlisting>
 224 <![CDATA[$ sudo systemctl --system daemon-reload
 225 $ sudo systemctl start proxy-with-nginx.socket
 226 $ sudo systemctl enable proxy-with-nginx.socket
 227 $ curl http://localhost:80/]]>
 228 </programlisting>
 229                         </example>
 230                 </refsect2>
 231         </refsect1>
 232         <refsect1>
 233                 <title>See Also</title>
 234                 <para>
 235                 <citerefentry>
 236                         <refentrytitle>
 237                         systemd.service</refentrytitle>
 238                         <manvolnum>5</manvolnum>
 239                 </citerefentry>,
 240                 <citerefentry>
 241                         <refentrytitle>
 242                         systemd.socket</refentrytitle>
 243                         <manvolnum>5</manvolnum>
 244                 </citerefentry>,
 245                 <citerefentry>
 246                         <refentrytitle>systemctl</refentrytitle>
 247                         <manvolnum>1</manvolnum>
 248                 </citerefentry>,
 249                 <citerefentry>
 250                         <refentrytitle>socat</refentrytitle>
 251                         <manvolnum>1</manvolnum>
 252                 </citerefentry></para>
 253         </refsect1>
 254 </refentry>