unitfile_service — Service unitfile configuration
name
.service
A unit configuration file whose name ends in
.service
encodes information about a process managed
by InitWare.
This man page lists the configuration options specific to this unit
type. See
unitfile(5)
for the common options of all unit configuration files.
The common configuration items are configured in the generic
[Unit]
and
[Install]
sections. The
service specific configuration options are configured in the
[Service]
section.
Additional options are listed in unitfile_exec(5) , which define the execution environment the commands are executed in, and in unitfile_kill(5) , which define the way the processes of the service are terminated, and in unitfile_rlimit(5) , which configure resource control settings for the processes of the service.
Unless
DefaultDependencies=
is set to
false
, service units will implicitly have
dependencies of type
Requires=
and
After=
on
basic.target
as well as
dependencies of type
Conflicts=
and
Before=
on
shutdown.target
. These
ensure that normal service units pull in basic system initialization, and
are terminated cleanly prior to system shutdown. Only services involved
with early boot or late system shutdown should disable this option.
If a service is requested under a certain name but no unit
configuration file is found, the InitWare scheduler looks for a SysV init
script by the same name (with the
.service
suffix
removed) and dynamically creates a service unit from that 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.
Service files must include a
[Service]
section,
which carries information about the service and the process it supervises.
A number of options that may be used in this section are shared with other
unit types. These options are documented in
unitfile_exec(5)
and
unitfile_kill(5)
. The options specific to the
[Service]
section of service units are the
following:
Type=
Configures the process start-up type for this service unit.
One of
simple
,
forking
,
oneshot
,
dbus
,
notify
or
idle
.
If set to
simple
(the
default 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 should be installed before the daemon is started up (e.g.
sockets set up by the InitWare scheduler, via socket activation), as
the scheduler will immediately proceed starting follow-up
units.
If set to
forking
, 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 are set up. The
child continues to run as the main daemon process. This is the
behavior of traditional UNIX daemons. If this setting is used, it is
recommended to also use the
PIDFile=
option, so
that the scheduler can identify the main process of the daemon. The
scheduler will proceed with starting follow-up units as soon as the
parent process exits.
Behavior of
oneshot
is
similar to
simple
; however, it
is expected that the process has to exit before the scheduler starts
follow-up units.
RemainAfterExit=
is particularly
useful for this type of service.
Behavior of
dbus
is
similar to
simple
; however, it
is expected that the daemon acquires a name on the D-Bus bus, as
configured by
BusName=
. The scheduler 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
dbus.socket
unit. This
type is the default if
BusName=
is
specified.
Behavior of
notify
is
similar to
simple
; however, it
is expected that the daemon sends a notification message via
sd_notify(3)
or an equivalent call when it has finished
starting up. The scheduler will proceed with starting follow-up
units after this notification message has been sent. If this option
is used,
NotifyAccess=
(see below) should be set
to open access to the notification socket provided by the scheduler.
If
NotifyAccess=
is not set, it will be
implicitly set to
main
. Note
that currently
Type=
notify
will not work if used in
combination with
PrivateNetwork=
yes
.
Behavior of
idle
is very
similar to
simple
; 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.
RemainAfterExit=
Takes a boolean value that specifies whether the service shall
be considered active even when all its processes exited. Defaults to
no
.
GuessMainPID=
Takes a boolean value that specifies whether the InitWare
scheduler should try to guess the main PID of a service if it cannot
be determined reliably. This option is ignored unless
Type=forking
is set and
PIDFile=
is unset because for the other types or
with an explicitly configured PID 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, failure detection and automatic restarting of a
service will not work reliably. Defaults to
yes
.
PIDFile=
Takes an absolute file name pointing to the PID file of this
daemon. Use of this option is recommended for services where
Type=
is set to
forking
. The scheduler will read the PID
of the main process of the daemon after start-up of the service. The
scheduler will not write to the file configured here.
BusName=
Takes a D-Bus bus name that this service is reachable as. This
option is mandatory for services where
Type=
is
set to
dbus
, but its use is
otherwise recommended if the process takes a name on the D-Bus
bus.
ExecStart=
Commands with their arguments that are executed when this service is started. For each of the specified commands, the first argument must be an absolute and literal path to an executable.
When
Type
is not
oneshot
, only one command may 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. 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 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
unitfile(5)
. 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 the section "Environment variables in spawned processes" in
unitfile_exec(5)
, 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
@
, the second token will be passed as
argv[0]
to the executed process, followed by the
further arguments specified. If the absolute filename is prefixed
with
-
, an exit code of the command normally
considered a failure (i.e. non-zero exit status or abnormal exit due
to signal) is ignored and considered success. If both
-
and
@
are used, they can
appear in either order.
Note that this setting does not directly support shell command lines. If shell command lines are to be used, they need to be passed explicitly to a shell implementation of some kind. Example:
ExecStart=/bin/sh -c 'dmesg | tac'
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
.
ExecStartPre=
,
ExecStartPost=
Additional commands that are executed before or after the
command in
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.
ExecReload=
Commands to execute to trigger a configuration reload in the
service. This argument takes multiple command lines, following the
same 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 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
no only triggers a configuration reload of the daemon, but also
synchronously waits for it complete.
ExecStop=
Commands to execute to stop the service started via
ExecStart=
. This argument takes multiple command
lines, following the same scheme as described for
ExecStart=
above. Use of this setting is
optional. After the commands configured in this option are run, all
processes remaining for a service are terminated according to the
KillMode=
setting (see
unitfile_kill(5)
). If this option is not specified, the process is
terminated immediately when service stop is requested. Specifier and
environment variable substitution is supported (including
$MAINPID
, see above).
ExecStopPost=
Additional commands that are executed after the service 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 of these settings is optional.
Specifier and environment variable substitution is supported.
RestartSec=
Configures the time to sleep before restarting a service (as
configured with
Restart=
). Takes a unit-less
value in seconds, or a time span value such as "5min 20s". Defaults
to 100ms.
TimeoutStartSec=
Configures the time to wait for start-up. If a daemon service
does not signal start-up completion within the configured time, the
service will be 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
DefaultTimeoutStartSec=
from the
manager configuration file, except when
Type=oneshot
is used, in which case the timeout
is disabled by default (see
systemd-systemd.conf(5)
).
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 timeout of equal duration with
SIGKILL
(see
KillMode=
in
unitfile_kill(5)
). 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
DefaultTimeoutStopSec=
from the manager
configuration file (see
systemd-systemd.conf(5)
).
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_notify(3)
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 failed
state. By setting
Restart=
to
on-failure
or
always
, 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
the scheduler. If
NotifyAccess=
is not set, it
will be implicitly set to
main
. Defaults to 0, which disables this
feature.
Restart=
Configures whether the 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 it may also be
one of the processes specified with
ExecStartPre=
,
ExecStartPost=
,
ExecStop=
,
ExecStopPost=
, or
ExecReload=
. When the death of the process is a
result of scheduler 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
no
,
on-success
,
on-failure
,
on-watchdog
,
on-abort
, or
always
. If set to
no
(the default), the service will not be
restarted. If set to
on-success
, 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
on-failure
, the service will be restarted
when the process exits with a non-zero 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
on-abort
,
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
on-watchdog
, the service
will be restarted only if the watchdog timeout for the service
expires. If set to
always
, 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
RestartPreventExitStatus=
(see below).
SuccessExitStatus=
Takes a list of exit status definitions that when returned by
the main service process will be considered successful termination,
in addition to the normal successful exit code 0 and the signals
SIGHUP
,
SIGINT
,
SIGTERM
, and
SIGPIPE
. Exit
status definitions can either be numeric exit codes or termination
signal names, separated by spaces. For example:
SuccessExitStatus=1 2 8
SIGKILL
ensures that exit codes 1, 2, 8 and the termination signal
SIGKILL
are considered clean service
terminations.
Note that if a process has a signal handler installed and exits by calling _exit(2) in response to a signal, the information about the signal is lost. Programs should instead perform cleanup and kill themselves with the same signal instead. See Proper handling of SIGINT/SIGQUIT — How to be a proper program .
This option may appear more than once, in which case the list of successful exit statuses is merged. If the empty string is assigned to this option, the list is reset, all prior assignments of this option will have no effect.
RestartPreventExitStatus=
Takes a list of exit status definitions that when returned by
the main service process will prevent automatic service restarts,
regardless of the restart setting configured with
Restart=
. Exit status definitions can either be
numeric exit codes or termination signal names, and are separated by
spaces. Defaults to the empty list, so that, by default, no exit
status is excluded from the configured restart logic. Example:
RestartPreventExitStatus=1 6 SIGABRT
, ensures
that exit codes 1 and 6 and the termination signal
SIGABRT
will not result in automatic service
restarting. This option may appear more than once, in which case the
list of restart-preventing statuses is merged. If the empty string
is assigned to this option, the list is reset and all prior
assignments of this option will have no effect.
PermissionsStartOnly=
Takes a boolean argument. If true, the permission-related
execution options, as configured with
User=
and
similar options (see
unitfile_exec(5)
for more information), are only applied to the
process started with
ExecStart=
, and not to the
various other
ExecStartPre=
,
ExecStartPost=
,
ExecReload=
,
ExecStop=
, and
ExecStopPost=
commands. If false, the setting is applied to all configured
commands the same way. Defaults to false.
RootDirectoryStartOnly=
Takes a boolean argument. If true, the root directory, as
configured with the
RootDirectory=
option (see
unitfile_exec(5)
for more information), is only applied to the
process started with
ExecStart=
, and not to the
various other
ExecStartPre=
,
ExecStartPost=
,
ExecReload=
,
ExecStop=
, and
ExecStopPost=
commands. If false, the setting is applied to all configured
commands the same way. Defaults to false.
NonBlocking=
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, 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
unitfile_socket(5)
. Defaults to false.
NotifyAccess=
Controls access to the service status notification socket, as
accessible via the
sd_notify(3)
call. Takes one of
none
(the default),
main
or
all
. If
none
, no daemon status updates are
accepted from the service processes, all status update messages are
ignored. If
main
, only service
updates sent from the main process of the service are accepted. If
all
, 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
WatchdogSec=
(see above). If those options are used but
NotifyAccess=
is not configured, it will be
implicitly set to
main
.
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 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 that which inherits the sockets.
Or in other words: the
Service=
setting of
.socket
units 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, and all prior uses of this setting will have no effect.
StartLimitInterval=
,
StartLimitBurst=
Configure service 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 10 second interval ends.
With these two options, this rate limiting may be modified. Use
StartLimitInterval=
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
DefaultStartLimitBurst=
in manager configuration
file). These configuration options are particularly useful in
conjunction with
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 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
none
,
reboot
,
reboot-force
, or
reboot-immediate
. If
none
is set, hitting the rate limit will
trigger no action besides that the start will not be permitted.
reboot
causes a reboot
following the normal shutdown procedure (i.e. equivalent to
systemctl reboot
).
reboot-force
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
reboot-immediate
causes immediate
execution of the
reboot(2)
system call, which might result in data loss.
Defaults to
none
.
Check unitfile_exec(5) and unitfile_kill(5) for more settings.
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 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
unitfile(5)
. 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
unitfile(5)
. If used, pass an integer value in the same range
as
/etc/fstab
's fs_passno column. See
fstab(5)
for details.
systemd(1) , systemctl(1) , unitfile(5) , unitfile_exec(5) , unitfile_rlimit(5) , unitfile_kill(5) , unitfile_directives(7)