<title>Description</title>
<para>A unit configuration file whose name ends in
- <filename>.socket</filename> encodes information about
+ <literal>.socket</literal> encodes information about
an IPC or network socket or a file system FIFO
controlled and supervised by systemd, for socket-based
activation.</para>
<option>ExecStopPre=</option> and
<option>ExecStopPost=</option> commands are executed
in, and in
- <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
which define the way the processes are
- terminated.</para>
+ terminated, and in
+ <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which configure control group settings for the
+ processes of the service.</para>
<para>For each socket file a matching service file
(see
can be written in various formats:</para>
<para>If the address starts with a
- slash (/), it is read as file system
+ slash (<literal>/</literal>), it is read as file system
socket in the <constant>AF_UNIX</constant> socket
family.</para>
- <para>If the address starts with an
- at symbol (@) it is read as abstract
- namespace socket in the <constant>AF_UNIX</constant>
- family. The @ is replaced with a NUL
- character before binding. For details
- see
+ <para>If the address starts with an at
+ symbol (<literal>@</literal>) it is read as abstract
+ namespace socket in the
+ <constant>AF_UNIX</constant>
+ family. The <literal>@</literal> is
+ replaced with a
+ <constant>NUL</constant> character
+ before binding. For details see
<citerefentry><refentrytitle>unix</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
<para>If the address string is a
<citerefentry><refentrytitle>close</refentrytitle><manvolnum>2</manvolnum></citerefentry>
on the received socket before
exiting. However, it must not unlink
- the socket from a filesystem. It
- should note invoke
+ the socket from a file system. It
+ should not invoke
<citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>2</manvolnum></citerefentry>
on sockets it got with
<varname>Accept=false</varname>, but
are coming in, they will be refused
until at least one existing connection
is terminated. This setting has no
- effect for sockets configured with
+ effect on sockets configured with
<option>Accept=false</option> or datagram
sockets. Defaults to
64.</para></listitem>
for details.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>ReusePort=</varname></term>
+ <listitem><para>Takes a boolean
+ value. If true, allows multiple bind()s
+ to this TCP or UDP port. This
+ controls the SO_REUSEPORT socket
+ option. See
+ <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>SmackLabel=</varname></term>
<term><varname>SmackLabelIPIn=</varname></term>
respectively, i.e. the security label
of the FIFO, or the security label for
the incoming or outgoing connections
- of the socket, respectively. See
+ of the socket, respectively. See
<ulink
url="https://www.kernel.org/doc/Documentation/security/Smack.txt">Smack.txt</ulink>
for details.</para></listitem>
<listitem><para>Takes an integer
value. Controls the pipe buffer size
of FIFOs configured in this socket
- unit. See
+ unit. See
<citerefentry><refentrytitle>fcntl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
for details.</para></listitem>
</varlistentry>
socket option, which allows <constant>AF_UNIX</constant>
sockets to receive the security
context of the sending process in an
- ancillary message. Defaults to
+ ancillary message. Defaults to
<option>false</option>.</para></listitem>
</varlistentry>
before or after the listening
sockets/FIFOs are created and
bound, respectively. The first token of the command
- line must be an absolute file name,
+ line must be an absolute filename,
then followed by arguments for the
process. Multiple command lines may be
specified following the same scheme as
will be considered failed and be shut
down again. All commands still running,
will be terminated forcibly via
- SIGTERM, and after another delay of
- this time with SIGKILL. (See
+ <constant>SIGTERM</constant>, and after another delay of
+ this time with <constant>SIGKILL</constant>. (See
<option>KillMode=</option> in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
Takes a unit-less value in seconds, or
a time span value such as "5min
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
<para>
- For more extensive descriptions see the "Systemd for Developers" series:
+ For more extensive descriptions see the "systemd for Developers" series:
<ulink url="http://0pointer.de/blog/projects/socket-activation.html">Socket Activation</ulink>,
<ulink url="http://0pointer.de/blog/projects/socket-activation2.html">Socket Activation, part II</ulink>,
<ulink url="http://0pointer.de/blog/projects/inetd.html">Converting inetd Services</ulink>,
~ianmdlvl / elogind.git / blobdiff