man/systemd-socket-activate.xml

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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
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   8
   9 <refentry id="systemd-socket-activate"
  10           xmlns:xi="http://www.w3.org/2001/XInclude">
  11
  12   <refentryinfo>
  13     <title>systemd-socket-activate</title>
  14     <productname>systemd</productname>
  15
  16     <authorgroup>
  17       <author>
  18         <contrib>Developer</contrib>
  19         <firstname>Zbigniew</firstname>
  20         <surname>Jędrzejewski-Szmek</surname>
  21         <email>zbyszek@in.waw.pl</email>
  22       </author>
  23     </authorgroup>
  24   </refentryinfo>
  25
  26   <refmeta>
  27     <refentrytitle>systemd-socket-activate</refentrytitle>
  28     <manvolnum>1</manvolnum>
  29   </refmeta>
  30
  31   <refnamediv>
  32     <refname>systemd-socket-activate</refname>
  33     <refpurpose>Test socket activation of daemons</refpurpose>
  34   </refnamediv>
  35
  36   <refsynopsisdiv>
  37     <cmdsynopsis>
  38       <command>systemd-socket-activate</command>
  39       <arg choice="opt" rep="repeat">OPTIONS</arg>
  40       <arg choice="plain"><replaceable>daemon</replaceable></arg>
  41       <arg choice="opt" rep="repeat">OPTIONS</arg>
  42     </cmdsynopsis>
  43   </refsynopsisdiv>
  44
  45   <refsect1>
  46     <title>Description</title>
  47
  48     <para><command>systemd-socket-activate</command> may be used to launch a socket-activated service program from the
  49     command line for testing purposes. It may also be used to launch individual instances of the service program per
  50     connection.
  51     </para>
  52
  53     <para>The daemon to launch and its options should be specified
  54     after options intended for <command>systemd-socket-activate</command>.
  55     </para>
  56
  57     <para>If the <option>--inetd</option> option is given, the socket file descriptor will be used as the standard
  58     input and output of the launched process. Otherwise, standard input and output will be inherited, and sockets will
  59     be passed through file descriptors 3 and higher. Sockets passed through <varname>$LISTEN_FDS</varname> to
  60     <command>systemd-socket-activate</command> will be passed through to the daemon, in the original positions. Other sockets
  61     specified with <option>--listen=</option> will use consecutive descriptors.  By default,
  62     <command>systemd-socket-activate</command> listens on a stream socket, use <option>--datagram</option> and
  63     <option>--seqpacket</option> to listen on datagram or sequential packet sockets instead (see below).
  64     </para>
  65   </refsect1>
  66
  67   <refsect1>
  68     <title>Options</title>
  69     <variablelist>
  70       <varlistentry>
  71         <term><option>-l <replaceable>address</replaceable></option></term>
  72         <term><option>--listen=<replaceable>address</replaceable></option></term>
  73
  74         <listitem><para>Listen on this <replaceable>address</replaceable>.
  75         Takes a string like <literal>2000</literal> or
  76         <literal>127.0.0.1:2001</literal>.</para>
  77         </listitem>
  78       </varlistentry>
  79
  80       <varlistentry>
  81         <term><option>-a</option></term>
  82         <term><option>--accept</option></term>
  83
  84         <listitem><para>Launch an instance of the service program for each connection and pass the connection
  85         socket.</para></listitem>
  86       </varlistentry>
  87
  88       <varlistentry>
  89         <term><option>-d</option></term>
  90         <term><option>--datagram</option></term>
  91
  92         <listitem><para>Listen on a datagram socket (<constant>SOCK_DGRAM</constant>), instead of a stream socket
  93         (<constant>SOCK_STREAM</constant>). May not be combined with <option>--seqpacket</option>.</para></listitem>
  94       </varlistentry>
  95
  96       <varlistentry>
  97         <term><option>--seqpacket</option></term>
  98
  99         <listitem><para>Listen on a sequential packet socket (<constant>SOCK_SEQPACKET</constant>), instead of a stream
 100         socket (<constant>SOCK_STREAM</constant>). May not be combined with
 101         <option>--datagram</option>.</para></listitem>
 102       </varlistentry>
 103
 104       <varlistentry>
 105         <term><option>--inetd</option></term>
 106
 107         <listitem><para>Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
 108         output, instead of the new-style protocol for passing file descriptors using <varname>$LISTEN_FDS</varname>
 109         (see above).</para></listitem>
 110       </varlistentry>
 111
 112       <varlistentry>
 113         <term><option>-E <replaceable>VAR</replaceable><optional>=<replaceable>VALUE</replaceable></optional></option></term>
 114         <term><option>--setenv=<replaceable>VAR</replaceable><optional>=<replaceable>VALUE</replaceable></optional></option></term>
 115
 116         <listitem><para>Add this variable to the environment of the
 117         launched process. If <replaceable>VAR</replaceable> is
 118         followed by <literal>=</literal>, assume that it is a
 119         variable–value pair. Otherwise, obtain the value from the
 120         environment of <command>systemd-socket-activate</command> itself.
 121         </para></listitem>
 122       </varlistentry>
 123
 124       <varlistentry>
 125         <term><option>--fdname=</option><replaceable>NAME</replaceable><optional>:<replaceable>NAME</replaceable>…</optional></term>
 126
 127         <listitem><para>Specify names for the file descriptors passed. This is equivalent to setting
 128         <varname>FileDescriptorName=</varname> in socket unit files, and enables use of
 129         <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 130         Multiple entries may be specifies using separate options or by separating names with colons
 131         (<literal>:</literal>) in one option. In case more names are given than descriptors, superfluous ones will be
 132         ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
 133         </para></listitem>
 134       </varlistentry>
 135
 136       <xi:include href="standard-options.xml" xpointer="help" />
 137       <xi:include href="standard-options.xml" xpointer="version" />
 138     </variablelist>
 139   </refsect1>
 140
 141   <refsect1>
 142     <title>Environment variables</title>
 143     <variablelist class='environment-variables'>
 144       <varlistentry>
 145         <term><varname>$LISTEN_FDS</varname></term>
 146         <term><varname>$LISTEN_PID</varname></term>
 147         <term><varname>$LISTEN_FDNAMES</varname></term>
 148
 149         <listitem><para>See
 150         <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
 151       </varlistentry>
 152
 153       <varlistentry>
 154         <term><varname>$SYSTEMD_LOG_TARGET</varname></term>
 155         <term><varname>$SYSTEMD_LOG_LEVEL</varname></term>
 156         <term><varname>$SYSTEMD_LOG_COLOR</varname></term>
 157         <term><varname>$SYSTEMD_LOG_LOCATION</varname></term>
 158
 159         <listitem><para>Same as in
 160         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para></listitem>
 161       </varlistentry>
 162     </variablelist>
 163   </refsect1>
 164
 165   <refsect1>
 166     <title>Examples</title>
 167
 168     <example>
 169       <title>Run an echo server on port 2000</title>
 170
 171       <programlisting>$ systemd-socket-activate -l 2000 --inetd -a cat</programlisting>
 172     </example>
 173
 174     <example>
 175       <title>Run a socket-activated instance of <citerefentry><refentrytitle>systemd-journal-gatewayd</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
 176
 177       <programlisting>$ systemd-socket-activate -l 19531 /usr/lib/systemd/systemd-journal-gatewayd</programlisting>
 178     </example>
 179   </refsect1>
 180
 181   <refsect1>
 182     <title>See Also</title>
 183     <para>
 184       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 185       <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 186       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 187       <citerefentry><refentrytitle>systemd-run</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 188       <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 189       <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 190       <citerefentry project='man-pages'><refentrytitle>cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 191     </para>
 192   </refsect1>
 193 </refentry>