X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.service.xml;h=d316ab5d2ef3e465a99425e7dc6f30fba93260cf;hp=63e5b16e538c9bb6ad8b14066d63f62d255d08a2;hb=0de638530c0651e554cff06cb0bf7a8ccdff97ab;hpb=9cc2c8b763fb4b9ddda95756a727a438a0d2a012 diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 63e5b16e5..d316ab5d2 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -48,7 +48,7 @@ - systemd.service + service.service @@ -73,9 +73,12 @@ systemd.exec5, which define the execution environment the commands are executed in, and in - systemd.kill5 + systemd.kill5, which define the way the processes of the service are - terminated. + 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 @@ -121,7 +124,7 @@ options specific to the [Service] section of service units are the following: - + Type= @@ -136,14 +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 @@ -151,14 +156,14 @@ 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 behavior of traditional UNIX daemons. If this @@ -207,14 +212,18 @@ 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=. Behavior of is very similar @@ -255,7 +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 @@ -298,10 +307,14 @@ ExecStart= Commands with their arguments that are executed when this - service is started. - + service is started. For each of the + specified commands, the first argument + must be an absolute and literal path + to an executable. - When + When Type is + not , only one + command may be given. When Type=oneshot is used, more than one command may be specified. Multiple command lines may @@ -310,19 +323,51 @@ (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. - The commands are invoked one by - one sequentially in the order they - appear in the unit file. - When Type is - not , only one - command may be given. Lone semicolons - may be escaped as - '\;'. + 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 @@ -331,66 +376,111 @@ main process of the daemon. The command line accepts - '%' specifiers as + % 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. + 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 at + whitespace, resulting in zero or more + arguments. To pass a literal dollar + sign, use $$. + Variables whose value is not known at + expansion time are treated as empty + strings. Note that the first argument + (i.e. the program to execute) may not + be a variable. + + Variables to be used in this + fashion may be defined through + Environment= and + EnvironmentFile=. + In addition, variables listed in + section "Environment variables in + spawned processes" in + systemd.exec5 + which are considered "static + configuration" may used (this includes + e.g. $USER, but not + $TERM). 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 - absolute file name is prefixed with - '-' an exit code of + 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 + - and + @ are used, they can appear in either order. - On top of that 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 no or more - arguments. 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. - Note that this setting does not directly support shell command lines. If shell command lines are to - be used they need to be passed + 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. - + of some kind. Example: + ExecStart=/bin/sh -c 'dmesg | tac' + + + 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. + @@ -405,6 +495,11 @@ 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. @@ -420,14 +515,17 @@ optional. Specifier and environment variable substitution is supported here following the same scheme as for - ExecStart=. One - additional special environment - variables is set: if known - $MAINPID is set to + 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. + following: + + /bin/kill -HUP $MAINPID + @@ -446,12 +544,12 @@ KillMode= setting (see systemd.kill5). If - this option is not specified the + 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 + $MAINPID, see above). @@ -459,9 +557,12 @@ 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 described for ExecStart. Use @@ -495,9 +596,10 @@ 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 + logic. Defaults to TimeoutStartSec= from the + manager configuration file, except when Type=oneshot is - used in which case the timeout + used, in which case the timeout is disabled by default. @@ -508,15 +610,16 @@ 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 + forcibly via SIGTERM, and after another delay of this time with - SIGKILL (See + SIGKILL (See KillMode= 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. + logic. Defaults to TimeoutStartSec= from the + manager configuration file. @@ -532,18 +635,18 @@ 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 @@ -552,7 +655,7 @@ 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 @@ -567,37 +670,71 @@ 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 equaling 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). @@ -607,17 +744,34 @@ 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 + code 0 and the signals SIGHUP, SIGINT, + SIGTERM, and SIGPIPE. Exit status definitions can either be numeric exit - codes or termination signal names, and - are 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. + 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. @@ -636,11 +790,18 @@ 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. + 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. @@ -715,23 +876,23 @@ (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 . @@ -754,13 +915,22 @@ 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. @@ -768,20 +938,23 @@ 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 @@ -861,7 +1034,7 @@ for compatibility reasons and should not be used in newly written service files. - + SysVStartPriority= Set the SysV start @@ -885,33 +1058,6 @@ 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. - - @@ -922,6 +1068,7 @@ systemctl8, systemd.unit5, systemd.exec5, + systemd.resource-control5, systemd.kill5, systemd.directives7