X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.service.xml;h=0454cf292ef199c3a36bd94b995f5a1019e0bc01;hp=7200525c030ce412f6cb3d642d1e18d018ee860b;hb=d2bbca6855b174fb7ea90b4767a886bb88bd2400;hpb=3185a36b05d53757a412f847d8c510978b9b00f0 diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 7200525c0..0454cf292 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -9,16 +9,16 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> @@ -44,11 +44,11 @@ systemd.service - systemd service configuration files + Service unit configuration - systemd.service + service.service @@ -72,7 +72,10 @@ 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. Unless DefaultDependencies= is set to , service units will @@ -95,7 +98,12 @@ .service suffix removed) and dynamically creates a service unit from that script. This is useful for compatibility with - SysV. + SysV. Note that this compatibility is quite + comprehensive but not 100%. For details about the + incompatibilities see the Incompatibilities + with SysV document. + @@ -107,11 +115,13 @@ 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= @@ -121,12 +131,14 @@ , , , - . + or + . If set to (the default - value) it is expected that the process - configured with + value if BusName= + is not specified) it is expected that + the process configured with ExecStart= is the main process of the service. In this mode, if the process offers @@ -148,7 +160,7 @@ complete and all communication channels 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 @@ -159,7 +171,7 @@ soon as the parent process exits. - Behaviour of + Behavior of is similar to , however it is expected that the process has to @@ -168,7 +180,7 @@ is particularly useful for this type of service. - Behaviour of + Behavior of is similar to , however it is expected that the daemon acquires a @@ -180,10 +192,12 @@ acquired. Service units with this option configured implicitly gain dependencies on the - dbus.target - unit. + dbus.socket + unit. This type is the default if + BusName= is + specified. - Behaviour of + Behavior of is similar to , however it is expected that the daemon sends a @@ -198,9 +212,19 @@ below) should be set to open access to the notification socket provided by systemd. If - NotifyAccess= is not - set, it will implicitly be set to + NotifyAccess= is + not set, it will be implicitly set to . + + Behavior of + is very similar + to , however + actual execution of the service + binary is delayed until all jobs are + dispatched. This may be used to avoid + interleaving of output of shell + services with the status output on the + console. @@ -221,7 +245,7 @@ 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 @@ -259,7 +283,7 @@ 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 @@ -272,85 +296,131 @@ 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. The first + argument must be an absolute path + name. + + 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. + 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. However, + the latter syntax is not recommended + for compatibility with parsers + suitable for XDG + .desktop files. + 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. + + 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. 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 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 + whitespace it contains, resulting in a + single argument. Use + $FOO as a separate + 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 zero or + more arguments. Note that the first + argument (i.e. the program to execute) + may not be a variable, since it must + be a literal and absolute path + name. Optionally, if the absolute file name is prefixed with - @, the second token + '@', 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 + absolute file name 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 - 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. On - top of that basic environment variable - substitution is supported, where - ${FOO} is replaced - by the string value of the environment - variable of the same name. Also - $FOO may appear as - separate word on the command line in - which case the variable is replaced by - its value split at whitespaces. Note - that the first argument (i.e. the - binary to execute) may not be a - variable, and must be a literal and - absolute path name. + '-' 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' + + + For services run by a user + instance of systemd the special + environment variable + $MANAGERPID is set + to the PID of the systemd + instance. + 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. + @@ -359,20 +429,23 @@ 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 + @@ -381,22 +454,22 @@ 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). @@ -404,13 +477,15 @@ 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 doesn't 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 @@ -430,56 +505,205 @@ - 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 + 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 90s, 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 - 60s. + logic. Defaults to 90s. + + + + + TimeoutSec= + A shorthand for configuring + both TimeoutStartSec= + and TimeoutStopSec= + to the specified value. + + + + + WatchdogSec= + Configures the + 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 + is placed in a failure state. By + setting Restart= to + or + the service + will be automatically restarted. The + time configured here will be passed to + the executed service process in the + WATCHDOG_USEC= + environment variable. This allows + daemons to automatically enable the + keep-alive pinging logic if watchdog + support is enabled for the service. If + 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 + . Defaults to 0, + which disables this + feature. 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 + service will not be restarted. 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, or when - terminated by a signal. If set to - it will be - restarted only if it exits due to - reception of an uncaught signal. If - set to the - service will be restarted regardless - whether it exited cleanly or not, or - got terminated abnormally by a - signal. + 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, 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 regardless whether + it exited cleanly or not, got + terminated abnormally by a signal or + 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. Example: + "SuccessExitStatus=1 2 8 + SIGKILL", ensures that exit + codes 1, 2, 8 and the termination + signal SIGKILL are considered clean + service terminations. 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. @@ -529,100 +753,6 @@ false. - - SysVStartPriority= - Set the SysV start - priority to use to order this service - in relation to SysV services lacking - LSB headers. This option is only - necessary to fix ordering in relation - to legacy SysV services, that have no - ordering information encoded in the - script headers. As such it should only - be used as temporary compatibility - option, and not be used in new unit - files. 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 - range 0-99. - - - - 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 members of the process group of - the main service process are - killed. 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 @@ -657,10 +787,16 @@ accepted. If all services updates from all members of the service's control group are - accepted. This option must be set to + accepted. This option should be set to open access to the notification socket when using - Type=notify (see above). + Type=notify or + WatchdogSec= (see + above). If those options are used but + NotifyAccess= not + configured it will be implicitly set + to + . @@ -668,11 +804,11 @@ Specifies the name of the socket units this service shall inherit the sockets from when the - service (ignoring the different suffix - of course) is started. Normally it + service is started. Normally it should not be necessary to use this setting as all sockets whose unit shares the same name as the service + (ignoring the different suffix of course) are passed to the spawned process. @@ -681,13 +817,144 @@ 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. + doesn't 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. + + + + StartLimitInterval= + StartLimitBurst= + + Configure service + 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 + may be modified. Use + StartLimitInterval= + to configure the checking interval + (defaults to 10s, 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 + configuration options are particularly + useful in conjunction with + Restart=, however + apply to all kinds of starts + (including manual), not just those + triggered by the + Restart= logic. + Note that units which are configured + for Restart= and + which reach the start limit are not + attempted to be restarted anymore, + however they may still be restarted + manually at a later point from which + point on the restart logic is again + activated. Note that + systemctl + reset-failed will cause the + restart rate counter for a service to + be flushed, which is useful if the + administrator wants to manually start + a service and the start limit + interferes with + that. + + + + StartLimitAction= + + Configure the action + to take if the rate limit configured + with + StartLimitInterval= + and + StartLimitBurst= is + hit. Takes one of + , + , + or + . If + is set, + hitting the rate limit will trigger no + action besides that the start will not + be + permitted. + causes a reboot following the normal + shutdown procedure (i.e. equivalent to + systemctl reboot), + causes + an forced reboot which will terminate + all processes forcibly but should + cause no dirty file systems on reboot + (i.e. equivalent to systemctl + reboot -f) and + + causes immediate execution of the + reboot2 + system call, which might result in + data loss. Defaults to + . + + + + + Check + systemd.exec5 + and + systemd.kill5 + for more settings. + + + + + Compatibility Options + + The following options are also available in the + [Service] section, but exist purely + for compatibility reasons and should not be used in + newly written service files. + + + + SysVStartPriority= + Set the SysV start + priority to use to order this service + in relation to SysV services lacking + LSB headers. This option is only + necessary to fix ordering in relation + to legacy SysV services, that have no + ordering information encoded in the + script headers. As such it should only + be used as temporary compatibility + option, and not be used in new unit + files. 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 + range 0-99. @@ -726,7 +993,9 @@ systemd1, systemctl8, systemd.unit5, - systemd.exec5 + systemd.exec5, + systemd.kill5, + systemd.directives7