X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.service.xml;h=98507f405f96e96a632dd9d45031c5e99b5ff4dc;hp=491c3df1cb6a375eba0f0b221b41674fd610b880;hb=a9a305332b7faf0d0d16db04909badaf6a095fef;hpb=5389fedd99dacee6811057c8e49a6cb96ba6a52e diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 491c3df1c..98507f405 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -44,11 +44,11 @@ systemd.service - systemd service configuration files + Service unit configuration - systemd.service + service.service @@ -72,7 +72,13 @@ Additional options are listed in systemd.exec5, which define the execution environment the commands - are executed in. + are executed in, and in + systemd.kill5, + which define the way the processes of the service are + terminated, and in + systemd.resource-control5, + which configure resource control settings for the + processes of the service. Unless DefaultDependencies= is set to , service units will @@ -97,7 +103,7 @@ script. This is useful for compatibility with SysV. Note that this compatibility is quite comprehensive but not 100%. For details about the - incomptibilities see the Incompatibilities with SysV document. @@ -112,11 +118,13 @@ supervises. A number of options that may be used in this section are shared with other unit types. These options are documented in - systemd.exec5. The + systemd.exec5 + and + systemd.kill5. The options specific to the [Service] section of service units are the following: - + Type= @@ -131,14 +139,16 @@ If set to (the default - value if BusName= - is not specified) it is expected that - the process configured with + value if neither + Type= nor + BusName= are + specified), it is expected that the + process configured with ExecStart= is the main process of the service. In this mode, if the process offers functionality to other processes on - the system its communication channels + the system, its communication channels should be installed before the daemon is started up (e.g. sockets set up by systemd, via socket activation), as @@ -146,16 +156,16 @@ starting follow-up units. If set to - it is + , it is expected that the process configured with ExecStart= will call fork() as part of its start-up. The parent process is expected to exit when start-up is complete and all communication - channels set up. The child continues + channels are set up. The child continues to run as the main daemon - process. This is the behaviour of + process. This is the behavior of traditional UNIX daemons. If this setting is used, it is recommended to also use the @@ -166,7 +176,7 @@ soon as the parent process exits. - Behaviour of + Behavior of is similar to , however it is expected that the process has to @@ -175,7 +185,7 @@ is particularly useful for this type of service. - Behaviour of + Behavior of is similar to , however it is expected that the daemon acquires a @@ -192,7 +202,7 @@ BusName= is specified. - Behaviour of + Behavior of is similar to , however it is expected that the daemon sends a @@ -202,19 +212,23 @@ starting up. systemd will proceed starting follow-up units after this notification message has been sent. If - this option is used + this option is used, NotifyAccess= (see below) should be set to open access to the notification socket provided by systemd. If NotifyAccess= is not set, it will be implicitly set to - . + . Note that + currently + Type= + will not work if used in combination with + PrivateNetwork=. - Behaviour of + Behavior of is very similar to , however - actual execution of a the service + actual execution of the service binary is delayed until all jobs are dispatched. This may be used to avoid interleaving of output of shell @@ -240,7 +254,7 @@ Takes a boolean value that specifies whether systemd should try to guess the main PID of a service - should if it cannot be determined + if it cannot be determined reliably. This option is ignored unless is set and @@ -250,7 +264,7 @@ guessing algorithm might come to incorrect conclusions if a daemon consists of more than one process. If - the main PID cannot be determined + the main PID cannot be determined, failure detection and automatic restarting of a service will not work reliably. Defaults to @@ -278,7 +292,7 @@ BusName= Takes a D-Bus bus - name, where this service is reachable + name, that this service is reachable as. This option is mandatory for services where Type= is set to @@ -291,52 +305,89 @@ ExecStart= - Takes a command line - that is executed when this service - shall be started up. The first token - of the command line must be an - absolute file name, then followed by - arguments for the process. It is - mandatory to set this option for all - services. This option may not be - specified more than once, except when + Commands with their + arguments that are executed when this + service is started. For each of the + specified commands, the first argument + must be an absolute and literal path + to an executable. + + When Type is + not , only one + command may be given. When Type=oneshot is - used in which case more than one - ExecStart= line is - accepted which are then invoked one by - one, sequentially in the order they - appear in the unit file. - - Optionally, if the absolute file - name is prefixed with - @, the second token - will be passed as - argv[0] to the - executed process, followed by the - further arguments specified. If the - first token is prefixed with - - an exit code of - the command normally considered a - failure (i.e. non-zero exit status or - abnormal exit due to signal) is ignored - and considered success. If both - - and - @ are used for the - same command the former must precede - the latter. Unless + used, more than one command may be + specified. Multiple command lines may + be concatenated in a single directive, + by separating them with semicolons + (these semicolons must be passed as + separate words). Alternatively, this + directive may be specified more than + once with the same effect. + Lone semicolons may be escaped as + \;. If the empty + string is assigned to this option, the + list of commands to start is reset, + prior assignments of this option will + have no effect. + + Each command line is split on + whitespace, with the first item being + the command to execute, and the + subsequent items being the arguments. + Double quotes ("...") and single + quotes ('...') may be used, in which + case everything until the next + matching quote becomes part of the + same argument. Quotes themselves are + removed after parsing. In addition, a + trailing backslash + (\) may be used to + merge lines. This syntax is intended + to be very similar to shell syntax, + but only the meta-characters and + expansions described in the following + paragraphs are understood. + Specifically, redirection using + <, + <<, + >, and + >>, pipes + using |, and + running programs in the background + using & + and other elements of shell + syntax are not supported. + + + If more than one command is + specified, the commands are invoked + one by one sequentially in the order + they appear in the unit file. If one + of the commands fails (and is not + prefixed with -), + other lines are not executed and the + unit is considered failed. + + Unless Type=forking is set, the process started via this command line will be considered the - main process of the daemon. The - command line accepts % specifiers as - described in - systemd.unit5. + main process of the daemon. - On top of that basic environment - variable substitution is - supported. Use + The command line accepts + % specifiers as + described in + systemd.unit5. + Note that the first argument of the + command line (i.e. the program to + execute) may not include + specifiers. + + Basic environment variable + substitution is supported. Use ${FOO} as part of a - word, or as word of its own on the + word, or as a word of its own on the command line, in which case it will be replaced by the value of the environment variable including all @@ -346,38 +397,99 @@ word on the command line, in which case it will be replaced by the value of the environment variable split up - at whitespace, resulting in no or more - arguments. Note that the first + at whitespace, resulting in zero or + more arguments. To pass a literal dollar sign, + use $$. Note that the first argument (i.e. the program to execute) - may not be a variable, and must be a - literal and absolute path - name. + may not be a variable. + + Optionally, if the absolute file + name is prefixed with + @, the second token + will be passed as + argv[0] to the + executed process, followed by the + further arguments specified. If the + absolute filename is prefixed with + -, an exit code of + the command normally considered a + failure (i.e. non-zero exit status or + abnormal exit due to signal) is ignored + and considered success. If both + - and + @ are used, they + can appear in either order. + + Note that this setting does not + directly support shell command + lines. If shell command lines are to + be used, they need to be passed + explicitly to a shell implementation + of some kind. Example: + ExecStart=/bin/sh -c 'dmesg | tac' + + + Only select environment variables that + are set for executed commands. See + systemd.exec5. + + + Example: + ExecStart=/bin/echo one ; /bin/echo "two two" + + This will execute + /bin/echo two + times, each time with one argument, + one and + two two, + respectively. Since two commands are + specified, + Type=oneshot must + be used. + + Example: + ExecStart=/bin/echo / >/dev/null & \; \ +/bin/ls + + This will execute + /bin/echo with five + arguments: /, + >/dev/null, + &, + ;, and + /bin/ls. + + Example: + Environment="ONE=one" 'TWO=two two' +ExecStart=/bin/echo $ONE $TWO ${TWO} + + This will execute + /bin/echo with four + arguments: one, + two, + two, and + two two. + ExecStartPre= ExecStartPost= Additional commands - that are executed before (resp. after) + that are executed before or after the command in - ExecStart=. Multiple - command lines may be concatenated in a - single directive, by separating them - by semicolons (these semicolons must - be passed as separate words). In that - case, the commands are executed one - after the other, - serially. Alternatively, these - directives may be specified more than - once with the same effect. However, - the latter syntax is not recommended - for compatibility with parsers - suitable for XDG - .desktop files. - Use of these settings is - optional. Specifier and environment - variable substitution is - supported. + ExecStart=, respectively. + Syntax is the same as for + ExecStart=, except + that multiple command lines are allowed + and the commands are executed one + after the other, serially. + + If any of those commands (not + prefixed with -) + fail, the rest are not executed and + the unit is considered failed. + @@ -386,20 +498,23 @@ trigger a configuration reload in the service. This argument takes multiple command lines, following the same - scheme as pointed out for - ExecStartPre= + scheme as described for + ExecStart= above. Use of this setting is optional. Specifier and environment variable substitution is supported here following the same scheme as for - ExecStart=. One - special environment variable is set: - if known $MAINPID is - set to the main process of the - daemon, and may be used for command - lines like the following: - /bin/kill -HUP - $MAINPID. + ExecStart=. + + One additional special + environment variables is set: if known + $MAINPID is set to + the main process of the daemon, and + may be used for command lines like the + following: + + /bin/kill -HUP $MAINPID + @@ -408,22 +523,22 @@ stop the service started via ExecStart=. This argument takes multiple command lines, - following the same scheme as pointed - out for - ExecStartPre= + following the same scheme as described + for ExecStart= above. Use of this setting is optional. All processes remaining for a service after the commands configured in this option are run are terminated according to the KillMode= setting - (see below). If this option is not - specified the process is terminated - right-away when service stop is - requested. Specifier and environment - variable substitution is supported - (including - $MAINPID, see + (see + systemd.kill5). If + this option is not specified, the + process is terminated right-away when + service stop is requested. Specifier + and environment variable substitution + is supported (including + $MAINPID, see above). @@ -431,13 +546,15 @@ ExecStopPost= Additional commands that are executed after the service - was stopped using the commands - configured in - ExecStop=. This + was stopped. This includes cases where + the commands configured in + ExecStop= were used, + where the service does not have any + ExecStop= defined, or + where the service exited unexpectedly. This argument takes multiple command lines, - following the same scheme as pointed - out for - ExecStartPre. Use + following the same scheme as described + for ExecStart. Use of these settings is optional. Specifier and environment variable substitution is @@ -457,44 +574,68 @@ - TimeoutSec= + TimeoutStartSec= Configures the time to - wait for start-up and stop. If a + wait for start-up. If a daemon service does not signal start-up completion within the - configured time the service will be + configured time, the service will be considered failed and be shut down - again. If a service is asked to stop - but does not terminate in the - specified time it will be terminated - forcibly via SIGTERM, and after + again. + Takes a unit-less value in seconds, or a + time span value such as "5min + 20s". Pass 0 to disable the timeout + logic. Defaults to TimeoutStartSec= from the + manager configuration file, except when + Type=oneshot is + used, in which case the timeout + is disabled by default. + + + + + TimeoutStopSec= + Configures the time to + wait for stop. If a service is asked + to stop but does not terminate in the + specified time, it will be terminated + forcibly via SIGTERM, and after another delay of this time with - SIGKILL. (See + SIGKILL (See KillMode= - below.) Takes a unit-less value in seconds, or a + in systemd.kill5). + Takes a unit-less value in seconds, or a time span value such as "5min 20s". Pass 0 to disable the timeout - logic. Defaults to - 90s, except when Type=oneshot is - used in which case the timeout - is disabled by default. + logic. Defaults to TimeoutStartSec= from the + manager configuration file. + + + + + TimeoutSec= + A shorthand for configuring + both TimeoutStartSec= + and TimeoutStopSec= + to the specified value. + WatchdogSec= Configures the - watchdog timeout for a service. This - is activated when the start-up is + watchdog timeout for a service. The + watchdog is activated when the start-up is completed. The service must call sd_notify3 regularly with "WATCHDOG=1" (i.e. the "keep-alive ping"). If the time between two such calls is larger than - the configured time then the service + the configured time, then the service is placed in a failure state. By setting Restart= to or - the service + , the service will be automatically restarted. The time configured here will be passed to the executed service process in the @@ -503,7 +644,7 @@ daemons to automatically enable the keep-alive pinging logic if watchdog support is enabled for the service. If - this option is used + this option is used, NotifyAccess= (see below) should be set to open access to the notification socket provided by @@ -518,37 +659,138 @@ Restart= Configures whether the - main service process shall be - restarted when it exits. Takes one of + service shall be restarted when the + service process exits, is killed, + or a timeout is reached. The service + process may be the main service + process, but also one of the processes + specified with + ExecStartPre=, + ExecStartPost=, + ExecStopPre=, + ExecStopPost=, or + ExecReload=. + When the death of the process is a + result of systemd operation (e.g. service + stop or restart), the service will not be + restarted. Timeouts include missing + the watchdog "keep-alive ping" + deadline and a service start, reload, + and stop operation timeouts. + + Takes one of , , , - or + , + , or . If set to - (the default) the - service will not be restarted when it - exits. If set to - it will be - restarted only when it exited cleanly, - i.e. terminated with an exit code of - 0. If set to - it will be - restarted only when it exited with an - exit code not equalling 0, when - terminated by a signal (including on + (the default), the + service will not be restarted. If set to + , it will be + restarted only when the service process + exits cleanly. + In this context, a clean exit means + an exit code of 0, or one of the signals + SIGHUP, SIGINT, SIGTERM, or SIGPIPE, and + additionally, exit statuses and signals + specified in SuccessExitStatus=. + If set to , + the service will be restarted when the + process exits with an nonzero exit code, + is terminated by a signal (including on core dump), when an operation (such as - service reload) times out or when the - configured watchdog timeout is - triggered. If set to - it will be - restarted only if it exits due to - reception of an uncaught signal - (including on core dump). If set to - the service - will be restarted regardless whether + service reload) times out, and when the + configured watchdog timeout is triggered. + If set to + , the service + will be restarted only if the service + process exits due to an uncaught + signal not specified as a clean exit + status. + If set to + , the service + will be restarted only if the watchdog + timeout for the service expires. + If set to + , the service + will be restarted regardless of whether it exited cleanly or not, got terminated abnormally by a signal or - hit a timeout. + hit a timeout. + + In addition to the above settings, + the service will not be restarted if the + exit code or signal is specified in + RestartPreventExitStatus= + (see below). + + + + SuccessExitStatus= + Takes a list of exit + status definitions that when returned + by the main service process will be + considered successful termination, in + addition to the normal successful exit + code 0 and the signals SIGHUP, SIGINT, + SIGTERM, and SIGPIPE. Exit status + definitions can either be numeric exit + codes or termination signal names, + separated by spaces. For example: + SuccessExitStatus=1 2 8 SIGKILL + ensures that exit codes 1, 2, 8 and + the termination signal + SIGKILL are + considered clean service terminations. + + + Note that if a process has a + signal handler installed and exits by + calling + _exit2 + in response to a signal, the + information about the signal is lost. + Programs should instead perform cleanup and kill themselves with the same signal instead. See + Proper handling of SIGINT/SIGQUIT — How to be a proper program. + + This option may appear more than once + in which case the list of successful + exit statuses is merged. If the empty + string is assigned to this option, the + list is reset, all prior assignments + of this option will have no + effect. + + + + RestartPreventExitStatus= + Takes a list of exit + status definitions that when returned + by the main service process will + prevent automatic service restarts + regardless of the restart setting + configured with + Restart=. Exit + status definitions can either be + numeric exit codes or termination + signal names, and are separated by + spaces. Defaults to the empty list, so + that by default no exit status is + excluded from the configured restart + logic. Example: + RestartPreventExitStatus=1 6 + SIGABRT, ensures that exit + codes 1 and 6 and the termination + signal SIGABRT will not result in + automatic service restarting. This + option may appear more than once in + which case the list of restart preventing + statuses is merged. If the empty + string is assigned to this option, the + list is reset, all prior assignments + of this option will have no + effect. @@ -598,72 +840,6 @@ false. - - KillMode= - Specifies how - processes of this service shall be - killed. One of - , - , - . - - If set to - all - remaining processes in the control - group of this service will be - terminated on service stop, after the - stop command (as configured with - ExecStop=) is - executed. If set to - only the main - process itself is killed. If set to - no process is - killed. In this case only the stop - command will be executed on service - stop, but no process be killed - otherwise. Processes remaining alive - after stop are left in their control - group and the control group continues - to exist after stop unless it is - empty. Defaults to - . - - Processes will first be - terminated via SIGTERM (unless the - signal to send is changed via - KillSignal=). If - then after a delay (configured via the - TimeoutSec= option) - processes still remain, the - termination request is repeated with - the SIGKILL signal (unless this is - disabled via the - SendSIGKILL= - option). See - kill2 - for more - information. - - - - KillSignal= - Specifies which signal - to use when killing a - service. Defaults to SIGTERM. - - - - - SendSIGKILL= - Specifies whether to - send SIGKILL to remaining processes - after a timeout, if the normal - shutdown procedure left processes of - the service around. Takes a boolean - value. Defaults to "yes". - - - NonBlocking= Set O_NONBLOCK flag @@ -689,23 +865,23 @@ (the default), or . If - no daemon status + , no daemon status updates are accepted from the service processes, all status update messages - are ignored. If + are ignored. If , only service updates sent from the main process of the service are - accepted. If all + accepted. If , all services updates from all members of the service's control group are accepted. This option should be set to open access to the notification socket when using Type=notify or - WatchdogUsec= (see + WatchdogSec= (see above). If those options are used but - NotifyAccess= not - configured it will be implicitly set + NotifyAccess= is not + configured, it will be implicitly set to . @@ -728,13 +904,22 @@ same time. Also note that a different service may be activated on incoming traffic than inherits the sockets. Or - in other words: The + in other words: the Service= setting of .socket units - doesn't have to match the inverse of the - Sockets= setting of - the .service it - refers to. + does not have to match the inverse of + the Sockets= + setting of the + .service it + refers to. + + This option may appear more than + once, in which case the list of socket + units is merged. If the empty string + is assigned to this option, the list of + sockets is reset, all prior uses of + this setting will have no + effect. @@ -742,20 +927,23 @@ StartLimitBurst= Configure service - start rate limiting. By default + start rate limiting. By default, services which are started more often than 5 times within 10s are not permitted to start any more times until the 10s interval ends. With - these two options this rate limiting + these two options, this rate limiting may be modified. Use StartLimitInterval= - to configure the checking interval - (defaults to 10s, set to 0 to disable + to configure the checking interval (defaults to + DefaultStartLimitInterval= in + manager configuration file, set to 0 to disable any kind of rate limiting). Use StartLimitBurst= to configure how many starts per interval - are allowed (defaults to 5). These + are allowed (defaults to + DefaultStartLimitBurst= in + manager configuration file). These configuration options are particularly useful in conjunction with Restart=, however @@ -818,6 +1006,13 @@ + + Check + systemd.exec5 + and + systemd.kill5 + for more settings. + @@ -828,7 +1023,7 @@ for compatibility reasons and should not be used in newly written service files. - + SysVStartPriority= Set the SysV start @@ -852,33 +1047,6 @@ range 0-99. - - FsckPassNo= - Set the fsck passno - priority to use to order this service - in relation to other file system - checking services. This option is only - necessary to fix ordering in relation - to fsck jobs automatically created for - all /etc/fstab - entries with a value in the fs_passno - column > 0. As such it should only be - used as option for fsck - services. Almost always it is a better - choice to add explicit ordering - directives via - After= or - Before=, - instead. For more details see - systemd.unit5. If - used, pass an integer value in the - same range as - /etc/fstab's - fs_passno column. See - fstab5 - for details. - - @@ -888,7 +1056,10 @@ systemd1, systemctl8, systemd.unit5, - systemd.exec5 + systemd.exec5, + systemd.resource-control5, + systemd.kill5, + systemd.directives7