X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.service.xml;h=da9079cbb8dfe37aafeae9c534711e7eeb50af0b;hp=8eda85f62db6546684545c5a2082b5cdccd5781d;hb=85a8eeee36b57c1ab382b0225fa9a87525bbeee9;hpb=79640424059328268b9fb6c5fa8eb777b27a177e diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 8eda85f62..da9079cbb 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -76,8 +76,8 @@ systemd.kill5, which define the way the processes of the service are terminated, and in - systemd.cgroup5, - which configure control group settings for the + systemd.resource-control5, + which configure resource control settings for the processes of the service. Unless DefaultDependencies= @@ -103,7 +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. @@ -139,9 +139,12 @@ If set to (the default - value if BusName= - is not specified), it is expected that - the process configured with + if neither + Type= nor + BusName=, but + ExecStart= 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 @@ -170,28 +173,32 @@ 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 - it is expected that the process has to + is similar to + ; however, it + is expected that the process has to exit before systemd starts follow-up units. RemainAfterExit= is particularly useful for this type - of service. + of service. This is the implied + default if neither + Type= or + ExecStart= are + specified. 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 @@ -202,12 +209,12 @@ 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, @@ -225,7 +232,7 @@ 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 @@ -258,7 +265,7 @@ 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 @@ -290,14 +297,52 @@ 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. + . + + + + + BusPolicy= + + If specified, a custom + kdbus + endpoint will be created and installed as the + default bus node for the service. Such a custom + endpoint can hold an own set of policy rules + that are enforced on top of the bus-wide ones. + The custom endpoint is named after the service + it was created for, and its node will be + bind-mounted over the default bus node + location, so the service can only access the + bus through its own endpoint. Note that custom + bus endpoints default to a 'deny all' policy. + Hence, if at least one + BusPolicy= directive is + given, you have to make sure to add explicit + rules for everything the service should be able + to do. + The value of this directive is comprised + of two parts; the bus name, and a verb to + specify to granted access, which is one of + , + , or + . + implies + , and + implies both and + . + If multiple access levels are specified for the + same bus name, the most powerful one takes + effect. + + Examples: + BusPolicy=org.freedesktop.systemd1 talk + BusPolicy=org.foo.bar see + This option is only available on kdbus enabled systems. @@ -305,78 +350,36 @@ 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. The value is split + into zero or more command lines is + according to the rules described below + (see section "Command Lines" below). + When Type is not , only one - command may be given. When + command may and must be given. When Type=oneshot is - 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 + used, zero or more commands may be + specified. This can be specified by + providing multiple command lines in + the same directive, or alternatively, + this directive may be specified more + than once with the same effect. 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 no + ExecStart= is + specified, then the service must have + RemainAfterExit=yes + set. + + For each of the specified + commands, the first argument must be + an absolute and literal path to an + executable. Optionally, if the + absolute file name is prefixed with @, the second token will be passed as argv[0] to the @@ -386,28 +389,28 @@ -, 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 + 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' - - - For services run by a user - instance of systemd the special - environment variable - $MANAGERPID is set - to the PID of the systemd - instance. - + If more than one command is + specified, the commands are invoked + 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. + + @@ -444,14 +447,28 @@ 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. @@ -464,15 +481,15 @@ 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 + process is terminated immediately when service stop is requested. Specifier and environment variable substitution is supported (including @@ -518,15 +535,18 @@ 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-system.conf5). @@ -534,17 +554,20 @@ 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-system.conf5). @@ -564,12 +587,13 @@ 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 - setting Restart= to + is placed in a failed state and it will + be terminated with SIGABRT. + By setting Restart= to or , the service will be automatically restarted. The @@ -599,11 +623,11 @@ 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 @@ -618,48 +642,151 @@ , , , + , , , 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=. + 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 only if the watchdog - timeout for the service expires. - If set to + 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 whether - it exited cleanly or not, got - terminated abnormally by a signal or + 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. + @@ -670,21 +797,32 @@ considered successful termination, in addition to the normal successful exit code 0 and the signals SIGHUP, SIGINT, - SIGTERM and SIGPIPE. Exit status + 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. @@ -693,7 +831,7 @@ 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 @@ -701,40 +839,52 @@ 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 + 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 @@ -745,19 +895,19 @@ 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 @@ -767,12 +917,14 @@ 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 @@ -815,21 +967,24 @@ Sockets= Specifies the name of the socket units this service shall - inherit the sockets from when the - service is started. Normally it - should not be necessary to use this - setting as all sockets whose unit + inherit socket file descriptors + from when the service is + started. Normally it should not be + necessary to use this setting as all + socket file descriptors whose unit shares the same name as the service - (ignoring the different suffix of course) - are passed to the spawned - process. - - Note that the same socket may be - 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 + (subject to the different unit name + suffix of course) are passed to the + spawned process. + + Note that the same socket file + descriptors may be passed to multiple + processes simultaneously. Also note + that a different service may be + activated on incoming socket traffic + than the one which is ultimately + configured to inherit the socket file + descriptors. Or in other words: the Service= setting of .socket units does not have to match the inverse of @@ -842,7 +997,7 @@ 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 + sockets is reset, and all prior uses of this setting will have no effect. @@ -853,33 +1008,36 @@ Configure service start rate limiting. By default, - services which are started more often - than 5 times within 10s are not + 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 + 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 @@ -903,30 +1061,63 @@ hit. Takes one of , , - or - . If - is set, - hitting the rate limit will trigger no - action besides that the start will not - be + , + , + , + 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 + systemctl reboot). + causes a + 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 + data loss. Similar, + , + , + + have the effect of powering down the + system with similar + semantics. Defaults to . + + 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 . + + + + + RebootArgument= + Configure the optional + argument for the + reboot2 + system call if + StartLimitAction= + or FailureAction= + is a reboot action. This works just + like the optional argument to + systemctl reboot + command. + + Check @@ -938,75 +1129,140 @@ - Compatibility Options + Command lines + + This section describes command line parsing and + variable and specifier substitions for + ExecStart=, + ExecStartPre=, + ExecStartPost=, + ExecReload=, + ExecStop=, and + ExecStopPost= options. + + Multiple command lines may be concatenated in a + single directive by separating them with semicolons + (these semicolons must be passed as separate words). + Lone semicolons may be escaped as + \;. + + 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 + |, running programs in the + background using &, and + other elements of shell syntax are not + supported. + + 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 at whitespace + resulting in zero or more arguments. For this type of + expansion, quotes and respected when splitting into + words, and afterwards removed. + + 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. + + Example: + Environment=ONE='one' "TWO='two two' too" THREE= +ExecStart=/bin/echo ${ONE} ${TWO} ${THREE} +ExecStart=/bin/echo $ONE $TWO $THREE + This results in echo being + called twice, the first time with arguments + 'one', + 'two two' too, , + and the second time with arguments + one, two two, + too. + - 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. + 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). - - - 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. - + Note that shell command lines are not directly + supported. 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' - - 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. - + 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. See Also systemd1, - systemctl8, + systemctl1, systemd.unit5, systemd.exec5, - systemd.cgroup5, + systemd.resource-control5, systemd.kill5, systemd.directives7