X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.service.xml;h=5c4bd6569f0ca7131281ea70fd58b8f7b57ae6a2;hp=dcf57c30bbaebd4c4b76b7e72a6fa081c9ffec93;hb=5e34b37c9fec5da130f6549ddabd8a2af5c9faac;hpb=909f413d3c572baadf9b13e36e1e90beba42af86 diff --git a/man/systemd.service.xml b/man/systemd.service.xml index dcf57c30b..5c4bd6569 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -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 @@ -100,7 +103,7 @@ script. This is useful for compatibility with SysV. Note that this compatibility is quite comprehensive but not 100%. For details about the - incompatibilities see the Incompatibilities with SysV document. @@ -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 @@ -167,13 +172,13 @@ PIDFile= option, so that systemd can identify the main process of the daemon. systemd will - proceed starting follow-up units as - soon as the parent process + proceed with starting follow-up units + as soon as the parent process exits. Behavior of is similar - to , however + to ; however, it is expected that the process has to exit before systemd starts follow-up units. RemainAfterExit= @@ -182,13 +187,13 @@ Behavior of is similar to - , however it is + ; however, it is expected that the daemon acquires a name on the D-Bus bus, as configured by BusName=. systemd - will proceed starting follow-up units - after the D-Bus bus name has been + will proceed with starting follow-up + units after the D-Bus bus name has been acquired. Service units with this option configured implicitly gain dependencies on the @@ -199,26 +204,30 @@ Behavior of is similar to - , however it is + ; however, it is expected that the daemon sends a notification message via sd_notify3 - or an equivalent call when it finished - starting up. systemd will proceed + or an equivalent call when it has finished + starting up. systemd will proceed with 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 - to , however + to ; however, actual execution of the service binary is delayed until all jobs are dispatched. This may be used to avoid @@ -251,11 +260,11 @@ is set and is unset because for the other types or with an explicitly configured PID - file the main PID is always known. The + file, the main PID is always known. The 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 @@ -283,14 +292,13 @@ BusName= Takes a D-Bus bus - name, that this service is reachable + name that this service is reachable as. This option is mandatory for services where Type= is set to , but its use - is otherwise recommended as well if - the process takes a name on the D-Bus - bus. + is otherwise recommended if the process + takes a name on the D-Bus bus. @@ -298,9 +306,10 @@ ExecStart= Commands with their arguments that are executed when this - service is started. The first - argument must be an absolute path - name. + 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 @@ -308,31 +317,56 @@ Type=oneshot is used, more than one command may be specified. Multiple command lines may - be concatenated in a single directive, + 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. + once with the same effect. Lone semicolons may be escaped as \;. If the empty - string is assigned to this option the + 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. + 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 @@ -343,30 +377,46 @@ 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. + 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 + 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 + 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. + 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 the + section "Environment variables in + spawned processes" in + systemd.exec5, + which are considered "static + configuration", may be used (this includes + e.g. $USER, but not + $TERM). Optionally, if the absolute file name is prefixed with @@ -375,32 +425,56 @@ 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 + @ 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 + 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. - + 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. Because 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. + @@ -437,14 +511,28 @@ here following the same scheme as for ExecStart=. - One additional special - environment variables is set: if known + One additional, 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 + + Note however that reloading a + daemon by sending a signal (as with + the example line above) is usually not + a good choice, because this is an + asynchronous operation and hence not + suitable to order reloads of multiple + services against each other. It is + strongly recommended to set + ExecReload= to a + command that not only triggers a + configuration reload of the daemon, + but also synchronously waits for it to + complete. @@ -457,15 +545,15 @@ 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 + optional. After the commands configured + in this option are run, all processes + remaining for a service are terminated according to the KillMode= setting (see systemd.kill5). If - this option is not specified the - process is terminated right-away when + this option is not specified, the + process is terminated immediately when service stop is requested. Specifier and environment variable substitution is supported (including @@ -480,7 +568,7 @@ was stopped. This includes cases where the commands configured in ExecStop= were used, - where the service doesn't have any + where the service does not have any ExecStop= defined, or where the service exited unexpectedly. This argument takes multiple command lines, @@ -511,15 +599,18 @@ daemon service does not signal start-up completion within the configured time, the service will be - considered failed and be shut down - again. + considered failed and will be shut + down 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. + 20s". Pass 0 to + disable the timeout logic. Defaults to + DefaultTimeoutStartSec= from + the manager configuration file, except + when Type=oneshot is + used, in which case the timeout + is disabled by default + (see systemd-systemd.conf5). @@ -527,17 +618,20 @@ TimeoutStopSec= Configures the time to wait for stop. If a service is asked - to stop but does not terminate in the + 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 + forcibly via SIGTERM, + and after another timeout of equal duration + with 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. + 20s". Pass 0 to disable + the timeout logic. Defaults to + DefaultTimeoutStopSec= from the + manager configuration file + (see systemd-systemd.conf5). @@ -557,14 +651,14 @@ 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 + 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 + the configured time, then the service + is placed in a failed 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 @@ -573,7 +667,7 @@ 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 @@ -592,11 +686,11 @@ 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 + process, but it may also be one of the + processes specified with ExecStartPre=, ExecStartPost=, - ExecStopPre=, + ExecStop=, ExecStopPost=, or ExecReload=. When the death of the process is a @@ -611,43 +705,151 @@ , , , + , + , , or . If set to - (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 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, 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 + process exits with a non-zero exit + code, is terminated by a signal + (including on core dump, but excluding + the aforementiond four signals), 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 when the + process is terminated by a signal + (including on core dump, excluding the + aforementioned four signals), when an + operation times out, or when the + 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. - In addition to the above settings, - the service will not be restarted if the - exit code or signal is specified in + + Exit causes and the effect of the <varname>Restart=</varname> settings on them + + + + + + + Restart settings/Exit causes + + + + + + + + + + + + Clean exit code or signal + + X + X + + + + + + + Unclean exit code + + X + + X + + + + + + Unclean signal + + X + + X + X + X + + + + Timeout + + X + + X + X + + + + + Watchdog + + X + + X + X + + X + + + +
+ + As exceptions to the setting + above the service will not be + restarted if the exit code or signal + is specified in RestartPreventExitStatus= - (see below). + (see below). Also, the services will + always be restarted if the exit code + or signal is specified in + RestartForceExitStatus= + (see below). + + Setting this to + is the + recommended choice for long-running + services, in order to increase + reliability by attempting automatic + recovery from errors. For services + that shall be able to terminate on + their own choice (and avoid + immediate restarting), + is an + alternative choice. + @@ -657,22 +859,33 @@ 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, - 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 + 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. @@ -681,7 +894,7 @@ Takes a list of exit status definitions that when returned by the main service process will - prevent automatic service restarts + prevent automatic service restarts, regardless of the restart setting configured with Restart=. Exit @@ -689,40 +902,52 @@ 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 + that, by default, no exit status is excluded from the configured restart - logic. Example: - RestartPreventExitStatus=1 6 - SIGABRT, ensures that exit + logic. For 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 + 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 + string is assigned to this option, the + list is reset and all prior assignments of this option will have no effect. + + RestartForceExitStatus= + Takes a list of exit + status definitions that when returned + by the main service process will force + automatic service restarts, regardless + of the restart setting configured with + Restart=. The + argument format is similar to + RestartPreventExitStatus=. + + PermissionsStartOnly= Takes a boolean - argument. If true, the permission - related execution options as + argument. If true, the permission-related + execution options, as configured with User= and similar options (see systemd.exec5 - for more information) are only applied + for more information), are only applied to the process started with ExecStart=, and not to the various other ExecStartPre=, ExecStartPost=, ExecReload=, - ExecStop=, + ExecStop=, and ExecStopPost= commands. If false, the setting is applied to all configured commands the @@ -733,19 +958,19 @@ RootDirectoryStartOnly= Takes a boolean - argument. If true, the root directory + argument. If true, the root directory, as configured with the RootDirectory= option (see systemd.exec5 - for more information) is only applied + for more information), is only applied to the process started with ExecStart=, and not to the various other ExecStartPre=, ExecStartPost=, ExecReload=, - ExecStop=, + ExecStop=, and ExecStopPost= commands. If false, the setting is applied to all configured commands the @@ -755,12 +980,14 @@ NonBlocking= - Set O_NONBLOCK flag + Set the + O_NONBLOCK flag for all file descriptors passed via socket-based activation. If true, all file descriptors >= 3 (i.e. all except - STDIN/STDOUT/STDERR) will have - the O_NONBLOCK flag set and hence are in + stdin, stdout, and stderr) will have + the O_NONBLOCK flag + set and hence are in non-blocking mode. This option is only useful in conjunction with a socket unit, as described in @@ -778,13 +1005,13 @@ (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 @@ -793,8 +1020,8 @@ Type=notify or 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 . @@ -816,11 +1043,11 @@ passed to multiple processes at the same time. Also note that a different service may be activated on incoming - traffic than inherits the sockets. Or - in other words: the + traffic than that which inherits the + sockets. Or in other words: the Service= setting of .socket units - doesn't have to match the inverse of + does not have to match the inverse of the Sockets= setting of the .service it @@ -829,8 +1056,8 @@ 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 + is assigned to this option, the list of + sockets is reset, and all prior uses of this setting will have no effect. @@ -840,34 +1067,37 @@ StartLimitBurst= Configure service - start rate limiting. By default - services which are started more often - than 5 times within 10s are not + start rate limiting. By default, + services which are started more + than 5 times within 10 seconds are not permitted to start any more times - until the 10s interval ends. With - these two options this rate limiting + until the 10 second 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 + 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 - apply to all kinds of starts + Restart=; however, + they 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 + 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 @@ -891,18 +1121,17 @@ hit. Takes one of , , - or + , or . If is set, hitting the rate limit will trigger no action besides that the start will not - be - permitted. + be permitted. causes a reboot following the normal shutdown procedure (i.e. equivalent to - systemctl reboot), + systemctl reboot). causes - an forced reboot which will terminate + a forced reboot which will terminate all processes forcibly but should cause no dirty file systems on reboot (i.e. equivalent to systemctl @@ -911,10 +1140,34 @@ causes immediate execution of the reboot2 system call, which might result in - data loss. Defaults to + data loss. Defaults to . + + RebootArgument= + Configure the optional + argument for the + reboot2 + system call if + StartLimitAction= + is a reboot action. This works just + like the optional argument to + systemctl reboot + command. + + + + FailureAction= + Configure the action + to take when the service enters a failed + state. Takes the same values as + StartLimitAction= + and executes the same actions. + Defaults to . + + + Check @@ -941,49 +1194,21 @@ 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 + 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 + script headers. As such, it should only + be used as a temporary compatibility + option and should 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 + instead. For more details, see + systemd.unit5. + If used, pass an integer value in the 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. - - @@ -994,6 +1219,7 @@ systemctl8, systemd.unit5, systemd.exec5, + systemd.resource-control5, systemd.kill5, systemd.directives7