man/systemd-socket-activate.xml

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