man/systemd-socket-activate.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="systemd-socket-activate"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-socket-activate</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-socket-activate</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-socket-activate</refname>
  21     <refpurpose>Test socket activation of daemons</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <cmdsynopsis>
  26       <command>systemd-socket-activate</command>
  27       <arg choice="opt" rep="repeat">OPTIONS</arg>
  28       <arg choice="plain"><replaceable>daemon</replaceable></arg>
  29       <arg choice="opt" rep="repeat">OPTIONS</arg>
  30     </cmdsynopsis>
  31   </refsynopsisdiv>
  32
  33   <refsect1>
  34     <title>Description</title>
  35
  36     <para><command>systemd-socket-activate</command> may be used to launch a socket-activated service program from the
  37     command line for testing purposes. It may also be used to launch individual instances of the service program per
  38     connection.
  39     </para>
  40
  41     <para>The daemon to launch and its options should be specified
  42     after options intended for <command>systemd-socket-activate</command>.
  43     </para>
  44
  45     <para>If the <option>--inetd</option> option is given, the socket file descriptor will be used as the standard
  46     input and output of the launched process. Otherwise, standard input and output will be inherited, and sockets will
  47     be passed through file descriptors 3 and higher. Sockets passed through <varname>$LISTEN_FDS</varname> to
  48     <command>systemd-socket-activate</command> will be passed through to the daemon, in the original positions. Other sockets
  49     specified with <option>--listen=</option> will use consecutive descriptors.  By default,
  50     <command>systemd-socket-activate</command> listens on a stream socket, use <option>--datagram</option> and
  51     <option>--seqpacket</option> to listen on datagram or sequential packet sockets instead (see below).
  52     </para>
  53   </refsect1>
  54
  55   <refsect1>
  56     <title>Options</title>
  57     <variablelist>
  58       <varlistentry>
  59         <term><option>-l <replaceable>address</replaceable></option></term>
  60         <term><option>--listen=<replaceable>address</replaceable></option></term>
  61
  62         <listitem><para>Listen on this <replaceable>address</replaceable>.
  63         Takes a string like <literal>2000</literal> or
  64         <literal>127.0.0.1:2001</literal>.</para>
  65         </listitem>
  66       </varlistentry>
  67
  68       <varlistentry>
  69         <term><option>-a</option></term>
  70         <term><option>--accept</option></term>
  71
  72         <listitem><para>Launch an instance of the service program for each connection and pass the connection
  73         socket.</para></listitem>
  74       </varlistentry>
  75
  76       <varlistentry>
  77         <term><option>-d</option></term>
  78         <term><option>--datagram</option></term>
  79
  80         <listitem><para>Listen on a datagram socket (<constant>SOCK_DGRAM</constant>), instead of a stream socket
  81         (<constant>SOCK_STREAM</constant>). May not be combined with <option>--seqpacket</option>.</para></listitem>
  82       </varlistentry>
  83
  84       <varlistentry>
  85         <term><option>--seqpacket</option></term>
  86
  87         <listitem><para>Listen on a sequential packet socket (<constant>SOCK_SEQPACKET</constant>), instead of a stream
  88         socket (<constant>SOCK_STREAM</constant>). May not be combined with
  89         <option>--datagram</option>.</para></listitem>
  90       </varlistentry>
  91
  92       <varlistentry>
  93         <term><option>--inetd</option></term>
  94
  95         <listitem><para>Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
  96         output, instead of the new-style protocol for passing file descriptors using <varname>$LISTEN_FDS</varname>
  97         (see above).</para></listitem>
  98       </varlistentry>
  99
 100       <varlistentry>
 101         <term><option>-E <replaceable>VAR</replaceable><optional>=<replaceable>VALUE</replaceable></optional></option></term>
 102         <term><option>--setenv=<replaceable>VAR</replaceable><optional>=<replaceable>VALUE</replaceable></optional></option></term>
 103
 104         <listitem><para>Add this variable to the environment of the
 105         launched process. If <replaceable>VAR</replaceable> is
 106         followed by <literal>=</literal>, assume that it is a
 107         variable–value pair. Otherwise, obtain the value from the
 108         environment of <command>systemd-socket-activate</command> itself.
 109         </para></listitem>
 110       </varlistentry>
 111
 112       <varlistentry>
 113         <term><option>--fdname=</option><replaceable>NAME</replaceable><optional>:<replaceable>NAME</replaceable>…</optional></term>
 114
 115         <listitem><para>Specify names for the file descriptors passed. This is equivalent to setting
 116         <varname>FileDescriptorName=</varname> in socket unit files, and enables use of
 117         <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 118         Multiple entries may be specifies using separate options or by separating names with colons
 119         (<literal>:</literal>) in one option. In case more names are given than descriptors, superfluous ones will be
 120         ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
 121         </para></listitem>
 122       </varlistentry>
 123
 124       <xi:include href="standard-options.xml" xpointer="help" />
 125       <xi:include href="standard-options.xml" xpointer="version" />
 126     </variablelist>
 127   </refsect1>
 128
 129   <refsect1>
 130     <title>Environment variables</title>
 131     <variablelist class='environment-variables'>
 132       <varlistentry>
 133         <term><varname>$LISTEN_FDS</varname></term>
 134         <term><varname>$LISTEN_PID</varname></term>
 135         <term><varname>$LISTEN_FDNAMES</varname></term>
 136
 137         <listitem><para>See
 138         <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
 139       </varlistentry>
 140
 141       <varlistentry>
 142         <term><varname>$SYSTEMD_LOG_TARGET</varname></term>
 143         <term><varname>$SYSTEMD_LOG_LEVEL</varname></term>
 144         <term><varname>$SYSTEMD_LOG_TIME</varname></term>
 145         <term><varname>$SYSTEMD_LOG_COLOR</varname></term>
 146         <term><varname>$SYSTEMD_LOG_LOCATION</varname></term>
 147
 148         <listitem><para>Same as in
 149         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para></listitem>
 150       </varlistentry>
 151     </variablelist>
 152   </refsect1>
 153
 154   <refsect1>
 155     <title>Examples</title>
 156
 157     <example>
 158       <title>Run an echo server on port 2000</title>
 159
 160       <programlisting>$ systemd-socket-activate -l 2000 --inetd -a cat</programlisting>
 161     </example>
 162
 163     <example>
 164       <title>Run a socket-activated instance of <citerefentry><refentrytitle>systemd-journal-gatewayd</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
 165
 166       <programlisting>$ systemd-socket-activate -l 19531 /usr/lib/systemd/systemd-journal-gatewayd</programlisting>
 167     </example>
 168   </refsect1>
 169
 170   <refsect1>
 171     <title>See Also</title>
 172     <para>
 173       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 174       <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 175       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 176       <citerefentry><refentrytitle>systemd-run</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 177       <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 178       <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 179       <citerefentry project='man-pages'><refentrytitle>cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 180     </para>
 181   </refsect1>
 182 </refentry>