X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.socket.xml;h=a7b8228aa0b6d7c5bb9fca0ba92052173a4e4c32;hp=65ef8c0b1ad29665f889addacc2edcc4e092d0e9;hb=20d910092d61dff9ae4e2500efd26ec68ca208b2;hpb=cdb788e4cdc67bf7da6b3b1b3f4f295ef5c25c67 diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml index 65ef8c0b1..a7b8228aa 100644 --- a/man/systemd.socket.xml +++ b/man/systemd.socket.xml @@ -54,10 +54,11 @@ Description - A unit configuration file whose name ends in .socket - encodes information about an IPC or network socket or - a file system FIFO controlled and supervised by systemd, - for socket-based activation. + A unit configuration file whose name ends in + .socket encodes information about + an IPC or network socket or a file system FIFO + controlled and supervised by systemd, for socket-based + activation. This man page lists the configuration options specific to this unit type. See @@ -69,15 +70,23 @@ in the [Socket] section. Additional options are listed in - systemd.exec5. - - For each socket file a matching service file (see systemd.service5 for details) - must exist, describing the service to start on - incoming traffic on the socket. Depending on the - setting of (see below) this - must either be named like the socket unit, but with - the suffix replaced; or it must be a template file - named the same way. Example: a socket file + systemd.exec5, + which define the execution environment the + , + , + and + commands are executed + in. + + For each socket file a matching service file + (see + systemd.service5 + for details) must exist, describing the service to + start on incoming traffic on the socket. Depending on + the setting of (see below), + this must either be named like the socket unit, but + with the suffix replaced; or it must be a template + file named the same way. Example: a socket file foo.socket needs a matching service foo.service if is set. If @@ -85,6 +94,25 @@ file foo@.service must exist from which services are instantiated for each incoming connection. + + Unless DefaultDependencies= + is set to , socket units will + implicitly have dependencies of type + Requires= and + After= on + sysinit.target as well as + dependencies of type Conflicts= and + Before= on + shutdown.target. These ensure + that socket units pull in basic system + initialization, and are terminated cleanly prior to + system shutdown. Only sockets involved with early + boot or late system shutdown should disable this + option. + + Socket units may be used to implement on-demand + starting of services, as well as parallelized starting + of services. @@ -96,7 +124,7 @@ this section are shared with other unit types. These options are documented in systemd.exec5. The - options specific to the [Socket] section of service + options specific to the [Socket] section of socket units are the following: @@ -157,7 +185,7 @@ regardless whether there is incoming traffic on them or not. - If an IP address is used here it + If an IP address is used here, it is often desirable to listen on it before the interface it is configured on is up and running, and even @@ -223,7 +251,7 @@ interfaces. This controls the SO_BINDTODEVICE socket option (see socket7 - for details). If this option is used + for details). If this option is used, an automatic dependency from this socket unit on the network interface device unit @@ -234,48 +262,51 @@ DirectoryMode= If listening on a file - system socket of FIFO the parent + system socket of FIFO, the parent directories are automatically created if needed. This option specifies the file system access mode used when - creating these directories. Defaults - to 0755. + creating these directories. Takes an + access mode in octal + notation. Defaults to + 0755. SocketMode= If listening on a file - system socket of FIFO this option + system socket of FIFO, this option specifies the file system access mode used when creating the file - node. Defaults to + node. Takes an access mode in octal + notation. Defaults to 0666. Accept= Takes a boolean - argument. If true a service instance + argument. If true, a service instance is spawned for each incoming connection and only the connection - socket is passed to it. If false all + socket is passed to it. If false, all listening sockets themselves are passed to the started service unit, and only one service unit is spawned for all connections (also see above). This value is ignored for datagram sockets and FIFOs where - unconditionally a single service unit + a single service unit unconditionally handles all incoming traffic. Defaults to . For - performance reasons it is recommended + performance reasons, it is recommended to write new daemons only in a way that is suitable for . This option is mostly useful to allow daemons designed for usage with - inetd8 - to work unmodified with system socket + inetd8, + to work unmodified with systemd socket activation. @@ -286,7 +317,7 @@ services instances for, when is set. If more concurrent connections - are coming in they will be refused, + are coming in, they will be refused until at least one existing connection is terminated. This setting has no effect for sockets configured with @@ -406,19 +437,33 @@ address. Defaults to . + + TCPCongestion= + Takes a string + value. Controls the TCP congestion + algorithm used by this socket. Should + be one of "westwood", "veno", "cubic", + "lp" or any other available algorithm + supported by the IP stack. This + setting applies only to stream + sockets. + + ExecStartPre= ExecStartPost= - Takes a command line - that is executed before (resp. after) - the listening sockets/FIFOs are created and + Takes one or more + command lines, which are executed + before (resp. after) the listening + sockets/FIFOs are created and bound. The first token of the command line must be an absolute file name, then followed by arguments for the - process. If specified more than once, - all commands are executed one after - the other, serially. Use of these - settings is optional. + process. Multiple command lines may be + specified following the same scheme as + used for + ExecStartPre= of + service unit files. @@ -427,11 +472,11 @@ Additional commands that are executed before (resp. after) the listening sockets/FIFOs are closed - and removed. If specified more than - once, all commands are executed one - after the other, serially. Use of - these settings is - optional. + and removed. Multiple command lines + may be specified following the same + scheme as used for + ExecStartPre= of + service unit files. @@ -442,10 +487,10 @@ ExecStartPost=, ExecStopPre= and ExecStopPost= to - finish. If a comand does not exit - within the configured time the socket + finish. If a command does not exit + within the configured time, the socket will be considered failed and be shut - down again. All commands still running + down again. All commands still running, will be terminated forcibly via SIGTERM, and after another delay of this time with SIGKILL. (See @@ -479,7 +524,7 @@ See Also - systemd8, + systemd1, systemctl8, systemd.unit5, systemd.exec5,