RUNSCRIPT(8) System Manager's Manual RUNSCRIPT(8)NAMErunscript — a means of hooking shell commands into a service
SYNOPSISrunscript [-D, --nodeps] [-d, --debug] [-s, --ifstarted]
[-S, --ifstopped] [-Z, --dry-run] [command ...]
DESCRIPTIONrunscript is basically an interpreter for shell scripts which provides an
easy interface to the often complex system commands and daemons. When a
service runs a command it first loads its multiplexed configuration file,
then its master configuration file, then /etc/rc.conf and finally the
script itself. At this point runscript then runs the command given.
Commands are defined as shell functions within the script. Here is a list
of some functions that all runscripts have by default:
describe Describes what the service does and each command the
service defines.
start First we ensure that any services we depend on are
started. If any needed services fail to start then we
exit with a suitable error, otherwise call the supplied
start function if it exists.
stop First we ensure that any services that depend on us are
stopped. If any services that need us fail to stop then
we exit with a suitable error, otherwise call the sup‐
plied stop function if it exists.
restart Stop and start the service, including dependencies. This
cannot be overridden. See the description of the RC_CMD
variable below for the method to make your service
behave differently when restart is being executed.
status Show the status of the service. The return code matches
the status, with the exception of "started" returning 0
to match standard command behaviour.
zap Resets the service state to stopped and removes all
saved data about the service.
The following options affect how the service is run:
-d, --debug Set xtrace on in the shell to assist in debugging.
-D, --nodeps Ignore all dependency information the service supplies.
-s, --ifstarted Only run the command if the service has been started.
-S, --ifstopped Only run the command if the service has been stopped.
-q, --quiet Turns off all informational output the service gener‐
ates. Output from any non OpenRC commands is not
affected.
-v, --verbose Turns on any extra informational output the service gen‐
erates.
-Z, --dry-run Shows what services would be stopped and/or started
without actually starting or stopping them.
The following variables affect the service script:
extra_commands Space separated list of extra commands the service
defines. These should not depend on the service being
stopped or started.
extra_started_commands
Space separated list of extra commands the service
defines. These only work if the service has already been
started.
extra_stopped_commands
Space separated list of extra commands the service
defines. These only work if the service has already been
stopped.
description String describing the service.
description_$command
String describing the extra command.
start_stop_daemon_args
List of arguments passed to start-stop-daemon when
starting the daemon.
command Daemon to start or stop via start-stop-daemon if no
start or stop function is defined by the service.
command_args List of arguments to pass to the daemon when starting.
command_background
Set this to "true", "yes" or "1" (case-insensitive) to
force the daemon into the background. This implies the
"--make-pidfile" and "--pidfile" option of
start-stop-daemon(8) so the pidfile variable must be
set.
pidfile Pidfile to use for the above defined command.
name Display name used for the above defined command.
retry Retry schedule to use when stopping the daemon. It can
either be a timeout in seconds or multiple signal/time‐
out pairs (like SIGTERM/5).
required_dirs A list of directories which must exist for the service
to start.
required_files A list of files which must exist for the service to
start.
DEPENDENCIES
You should define a depend function for the service so that runscript
will start and stop it in the right order in relation to other services.
As it's a function it can be very flexible, see the example below. Here
is a list of the functions you can use in a depend function. You simply
pass the names of the services to it to add to that dependency type, or
prefix it with ! to remove it.
need The service will refuse to start until needed services
have started and it will refuse to stop until any ser‐
vices that need it have stopped.
use The service will attempt to start any services we use
that have been added to the runlevel.
after The service will start after these services and stop
before these services.
before The service will start before these services and stop
after these services.
provide We provide this virtual service. For example, named pro‐
vides dns. Virtual services take precedence over real
services, so it is highly recommended that you do not
have a real service that has the same name as a virtual
service.
config We should recalculate our dependencies if the listed
files have changed.
keyword Tags a service with a keyword. These are the keywords we
currently understand:
-shutdown
Don't stop this service when shutting the system
down. This is normally quite safe as remaining
daemons will be sent a SIGTERM just before final
shutdown. Network related services such as the
network and dhcpcd init scripts normally have
this keyword.
-stop Don't stop this service when changing runlevels,
even if not present. This includes shutting the
system down.
-timeout
Other services should wait indefinitely for this
service to start. Use this keyword if your ser‐
vice may take longer than 60 seconds to start.
-jail When in a jail, exclude this service from any
dependencies. The service can still be run
directly. Set via rc_sys in /etc/rc.conf
-lxc Same as -jail, but for Linux Resource Containers
(LXC).
-openvz
Same as -jail, but for OpenVZ systems.
-prefix
Same as -jail, but for Prefix systems.
-uml Same as -jail, but for UML systems.
-vserver
Same as -jail, but for VServer systems.
-xen0 Same as -jail, but for Xen DOM0 systems.
-xenu Same as -jail, but for Xen DOMU systems.
To see how to influence dependencies in configuration files, see the
FILES section below.
BUILTINSrunscript defines some builtin functions that you can use inside your
service scripts:
einfo [string]
Output a green asterisk followed by the string.
ewarn [string]
Output a yellow asterisk followed by the string.
eerror [string]
Output a red asterisk followed by the string to stderr.
ebegin [string]
Same as einfo, but append 3 dots to the end.
eend retval [string]
If retval does not equal 0 then output the string using eerror
and !! in square brackets at the end of the line. Otherwise out‐
put ok in square brackets at the end of the line. The value of
retval is returned.
ewend retval [string]
Same as eend, but use ewarn instead of eerror.
You can prefix the above commands with the letter v, which means they
only output when the environment variable EINFO_VERBOSE is true.
ewaitfile timeout file1 file2 ...
Wait for timeout seconds until all files exist. Returns 0 if all
files exist, otherwise non zero. If timeout is less than 1 then
we wait indefinitely.
is_newer_than file1 file2 ...
If file1 is newer than file2 return 0, otherwise 1. If file2 is
a directory, then check all its contents too.
is_older_than file1 file2 ...
If file1 is newer than file2 return 0, otherwise 1. If file2 is
a directory, then check all its contents too.
service_set_value name value
Saves the name value for later retrieval. Saved values are lost
when the service stops.
service_get_value name
Returns the saved value called name.
service_started [service]
If the service is started, return 0 otherwise 1.
service_starting [service]
If the service is starting, return 0 otherwise 1.
service_inactive [service]
If the service is inactive, return 0 otherwise 1.
service_stopping [service]
If the service is stopping, return 0 otherwise 1.
service_stopped [service]
If the service is stopped, return 0 otherwise 1.
service_coldplugged [service]
If the service is coldplugged, return 0 otherwise 1.
service_wasinactive [service]
If the service was inactive, return 0 otherwise 1.
service_started_daemon [service] daemon [index]
If the service has started the daemon using start-stop-daemon,
return 0 otherwise 1. If an index is specified, it has to be the
nth daemon started by the service.
mark_service_started [service]
Mark the service as started.
mark_service_starting [service]
Mark the service as starting.
mark_service_inactive [service]
Mark the service as inactive.
mark_service_stopping [service]
Mark the service as stopping.
mark_service_stopped [service]
Mark the service as stopped.
mark_service_coldplugged [service]
Mark the service as coldplugged.
mark_service_wasinactive [service]
Mark the service as inactive.
checkpath [-D, --directory-truncate] [-d, --directory] [-F,
--file-truncate] [-f, --file] [-p, --pipe] [-m, --mode mode] [-o,
-owner owner] path ...
Checks to see if the path exists, is of the right type, owned by
the right people and has the correct access modes. If not, then
it corrects the path.
checkpath
[-W, --writable] path
checks to see if the path is writable.
yesno value
If value matches YES, TRUE, ON or 1 regardless of case then we
return 0, otherwise 1.
ENVIRONMENTrunscript sets the following environment variables for use in the service
scripts:
RC_SVCNAME Name of the service.
RC_RUNLEVEL Current runlevel that rc is in. Note that, in OpenRC,
the reboot runlevel is mapped to the shutdown runlevel.
This was done because most services do not need to know
if a system is shutting down or rebooting. If you are
writing a service that does need to know this, see the
RC_REBOOT variable.
RC_REBOOT This variable contains YES if the system is rebooting.
If your service needs to know the system is rebooting,
you should test this variable.
RC_BOOTLEVEL Boot runlevel chosen. Default is boot.
RC_DEFAULTLEVEL Default runlevel chosen. Default is default.
RC_SYS A special variable to describe the system more. Possi‐
ble values are OPENVZ, XENU, XEN0, UML and VSERVER.
RC_PREFIX In a Gentoo Prefix installation, this variable contains
the prefix offset. Otherwise it is undefined.
RC_UNAME The result of `uname -s`.
RC_CMD This contains the name of the command the service script
is executing, such as start, stop, restart etc. One
example of using this is to make a service script behave
differently when restart is being executed.
FILES
Configuration files, relative to the location of the service. If a file
ending with .${RC_RUNLEVEL} exists then we use that instead.
../conf.d/${RC_SVCNAME%%.*}
multiplexed configuration file. Example: if ${RC_SVCNAME} is net.eth1
then look for ../conf.d/net.
../conf.d/${RC_SVCNAME}
service configuration file.
/etc/rc.conf
host configuration file.
With the exception of /etc/rc.conf, the configuration files can also
influence the dependencies of the service through variables. Simply pre‐
fix the name of the dependency with rc_. Examples:
# Whilst most services don't bind to a specific interface, our
# openvpn configuration requires a specific interface, namely bge0.
rc_need="net.bge0"
# To put it in /etc/rc.conf you would do it like this
rc_openvpn_need="net.bge0"
# Services should not depend on the tap1 interface for network,
# but we need to add net.tap1 to the default runlevel to start it.
rc_provide="!net"
# To put it in /etc/conf.d/net you would do it like this
rc_provide_tap1="!net"
# To put in in /etc/rc.conf you would do it like this
rc_net_tap1_provide="!net"
# It's also possible to negate keywords. This is mainly useful for prefix
# users testing OpenRC.
rc_keyword="!-prefix"
EXAMPLES
An example service script for foo.
#!/sbin/runscript
command=/usr/bin/foo
command_args="${foo_args} --bar"
pidfile=/var/run/foo.pid
name="FooBar Daemon"
description="FooBar is a daemon that eats and drinks"
extra_commands="show"
extra_started_commands="drink eat"
description_drink="Opens mouth and reflexively swallows"
description_eat="Chews food in mouth"
description_show="Shows what's in the tummy"
_need_dbus()
{
grep -q dbus /etc/foo/plugins
}
depend()
{
# We write a pidfile and to /var/cache, so we need localmount.
need localmount
# We can optionally use the network, but it's not essential.
use net
# We should be after bootmisc so that /var/run is cleaned before
# we put our pidfile there.
after bootmisc
# Foo may use a dbus plugin.
# However, if we add the dbus plugin whilst foo is running and
# stop dbus, we don't need to stop foo as foo didn't use dbus.
config /etc/foo/plugins
local _need=
if service_started; then
_need=`service_get_value need`
else
if _need_dbus; then
_need="${_need} dbus"
fi
fi
need ${_need}
}
# This function does any pre-start setup. If it fails, the service will
# not be started.
# If you need this function to behave differently for a restart command,
# you should check the value of RC_CMD for "restart".
# This also applies to start_post, stop_pre and stop_post.
start_pre()
{
if [ "$RC_CMD" = restart ]; then
# This block will only execute for a restart command. Use a
# structure like this if you need special processing for a
# restart which you do not need for a normal start.
# The function can also fail from here, which will mean that a
# restart can fail.
# This logic can also be used in start_post, stop_pre and
# stop_post.
fi
# Ensure that our dirs are correct
checkpath --dir --owner foo:foo --mode 0664 \
/var/run/foo /var/cache/foo
}
start_post()
{
# Save our need
if _need_dbus; then
service_set_value need dbus
fi
}
stop_post() {
# Clean any spills
rm -rf /var/cache/foo/*
}
drink()
{
ebegin "Starting to drink"
${command} --drink beer
eend $? "Failed to drink any beer :("
}
eat()
{
local result=0 retval= ate= food=
ebegin "Starting to eat"
if yesno "${foo_diet}"; then
eend 1 "We are on a diet!"
return 1
fi
for food in /usr/share/food/*; do
veinfo "Eating `basename ${food}`"
${command} --eat ${food}
retval=$?
: $(( result += retval ))
[ ${retval} = 0 ] && ate="${ate} `basename ${food}`"
done
if eend ${result} "Failed to eat all the food"; then
service_set_value ate "${ate}"
fi
}
show()
{
einfo "Foo has eaten: `service_get_value ate`"
}
BUGS
Because of the way we load our configuration files and the need to handle
more than one service directory, you can only use symlinks in service
directories to other services in the same directory. You cannot symlink
to a service in a different directory even if it is another service
directory.
is_older_than should return 0 on success. Instead we return 1 to be com‐
pliant with Gentoo baselayout. Users are encouraged to use the
is_newer_than function which returns correctly.
SEE ALSOeinfo(3), rc(8), rc-status(8), rc-update(8), rc_plugin_hook(3), sh(1p),
start-stop-daemon(8), uname(1)AUTHORS
Roy Marples <roy@marples.name>
OpenRC December 31, 2011 OpenRC
