NAME¶
initctl - init daemon control tool
SYNOPSIS¶
initctl [
OPTION]...
COMMAND [
OPTION]...
ARG...
DESCRIPTION¶
initctl allows a system administrator to communicate and interact with
the Upstart
init(8) daemon.
If D-Bus has been configured to allow non-privileged users to invoke all Upstart
D-Bus methods, this command is also able to manage user jobs. See
init(5) for further details.
When run as
initctl, the first non-option argument is the
COMMAND.
Global options may be specified before or after the command.
You may also create symbolic or hard links to
initctl named after
commands. When invoked through these links the tool will behave only as that
command, with global and command-specific options intermixed. The default
installation supplies such links for the
start,
stop,
restart,
reload and
status commands.
OPTIONS¶
- --user
- User mode. In this mode, initctl will talk to the init(8) daemon
using the D-Bus private socket defined in the UPSTART_SESSION
environment variable.
Note that if the UPSTART_SESSION variable is defined, this option is
implied.
- --session
- Connect to init(8) daemon using the existing D-Bus session bus (for
testing purposes only).
- --system
- Communication with the init(8) daemon is normally performed over a
private socket connection. This has the advantage of speed and robustness,
when issuing commands to start or stop services or even reboot the system
you do not want to be affected by changes to the D-Bus system bus daemon.
The disadvantage to using the private socket however is security,
init(8) only permits the root user to communicate over this socket
which means that read-only commands such as status and list
cannot be made by other users.
The --system option instructs initctl to communicate via the
D-Bus system bus rather than over the private socket.
This is only possible if the system bus daemon is running and if
init(8) is connected to it. The advantage is that the default
security configuration allows non-root users to use read-only
commands.
- --dest
- Specifies the well-known name of the init(8) daemon when using
--system.
There is normally no need to use this option since the init(8) daemon
uses the default com.ubuntu.Upstart name. However it may be useful
for debugging.
- --no-wait
- Applies to the start, stop, restart and emit
commands.
Normally initctl will wait for the command to finish before
returning.
For the start, stop and restart commands, finishing
means that the named job is running (or has finished for tasks) or has
been fully stopped.
For the emit command, finishing means that all of the jobs affected
by the event are running (or have finished for tasks) or have been fully
stopped.
This option instead causes these commands to only wait for the goal change
or event to be queued.
- --quiet
- Reduces output of all commands to errors only.
COMMANDS¶
- start
- JOB [KEY=VALUE]...
Requests that a new instance of the named JOB be started, outputting
the status of the job to standard output when the command completes.
See status for a description of the output format.
The optional KEY=VALUE arguments specify environment variables to be
passed to the starting job, and placed in its environment. They also serve
to specify which instance of multi-instance jobs should be started.
Most jobs only permit a single instance; those that use the instance
stanza in their configuration define a string expanded from environment
variables to name the instance. As many unique instances may be started as
unique names may be generated by the stanza. Thus the environment
variables also serve to select which instance of JOB is to be acted
upon.
If the job is already running, start will return an error.
When called from the pre-stop stanza of a job configuration,
start may be called without argument to cancel the
stop.
- stop
- JOB [KEY=VALUE]...
Requests that an instance of the named JOB be stopped, outputting the
status of the job to standard output when the command completes.
See status for a description of the output format and start
for a discussion on instances.
When called from the pre-start stanza of a job configuration,
stop may be called without an argument to cancel the
start.
- restart
- JOB [KEY=VALUE]...
Requests that an instance of the named JOB be restarted, outputting
the status of the job to standard output when the command completes.
The job instance being restarted will retain its original configuration. To
have the new instance run with the latest job configuration, stop
the job and then start it again instead.
See status for a description of the output format and start
for a discussion on instances.
Note that this command can only be used when there is an instance of
JOB, if there is none then it returns an error instead of starting
a new one.
- reload
- JOB [KEY=VALUE]...
Sends the SIGHUP signal to running process of the named JOB
instance.
See start for a discussion on instances.
- status
- JOB [KEY=VALUE]...
Requests the status an instance of the named JOB, outputting to
standard output.
See start for a discussion on instances.
For a single-instance job a line like the following is output:
job start/running, process 1234
The job name is given first followed by the current goal and state of the
selected instance. The goal is either start or stop, the
status may be one of waiting, starting, pre-start,
spawned, post-start, running, pre-stop,
stopping, killed or post-stop.
If the job has an active process, the process id will follow on the same
line. If the state is pre-start or post-stop this will be
the process id of the equivalent process, otherwise it will be the process
id of the main process.
job start/pre-start, process 902
The post-start and pre-stop states may have multiple processes
attached, the extra processes will follow on consecutive lines indented by
a tab:
job start/post-start, process 1234
post-start process 1357
If there is no main process, they may follow on the same line but will be
prefixed to indicate that it is not the main process id being given:
job start/post-start, (post-start) process 1357
Jobs that permit multiple instances have names for each instance, the output
is otherwise identical to the above except that the instance name follows
the job name in parentheses:
job (tty1) start/post-start, process 1234
post-start process 1357
- list
-
Requests a list of the known jobs and instances, outputs the status of each
to standard output.
Note that this command includes in the enumeration as-yet-to-run jobs (in
other words configuration files for which no job instances have yet been
created) in the output with status "stop/waiting". In effect
such entries denote configuration files which represent potential future
jobs.
See status for a description of the output format and start
for a discussion on instances.
No particular order is used for the output, and there is no difference in
the output (other than the instance name appearing in parentheses) between
single-instance and multiple-instance jobs.
- emit
- EVENT [KEY=VALUE]...
Requests that the named EVENT be emitted, potentially causing jobs to
be started and stopped depending on their use of the start on and
stop on stanzas in their configuration.
The optional KEY=VALUE arguments specify environment variables to be
included with the event and thus exported into the environment of any jobs
started and stopped by the event.
The environment may also serve to specify which instance of multi-instance
jobs should be started or stopped. See start for a discussion on
instances.
There is no limitation on the event names that may be emitted with this
command, you are free to invent new events and use them in your job
configurations.
The most well-known event used by the default Upstart configuration is the
runlevel(7) event. This is normally emitted by the
telinit(8) and shutdown(8) tools.
- reload-configuration
-
Requests that the init(8) daemon reloads its configuration.
This command is generally not necessary since init(8) watches its
configuration directories with inotify(7) and automatically reloads
in cases of changes.
No jobs will be started by this command.
- version
-
Requests and outputs the version of the running init daemon.
- log-priority
- [PRIORITY]
When called with a PRIORITY argument, it requests that the
init(8) daemon log all messages with that priority or greater. This
may be used to both increase and decrease the volume of logged messages.
PRIORITY may be one of debug, info, message,
warn, error or fatal.
When called without argument, it requests the current minimum message
priority that the init(8) daemon will log and outputs to standard
output.
- show-config
- [OPTIONS] [CONF]
Display emits, start on and stop on job configuration details (in that
order) for specified job configuration, CONF. If CONF is not
specified, list information for all valid job configurations.
Note that a job configuration is the name of a job configuration file,
without the extension. Note too that this information is static: it does
not refer to any running job.
For each event emitted, a separate line is displayed beginning with two
space characters followed by, 'emits event' where ' event'
denotes a single emitted event.
The start on and stop on conditions are listed on separate
lines beginning with two space characters and followed by 'start on' and
'stop on' respectively and ending with the appropriate condition.
If a job configuration has no emits, start on, or stop on conditions, the
name of the job configuration will be displayed with no further details.
Note that the start on and stop on conditions will be fully
bracketed, regardless of whether they appear like this in the job
configuration file. This is useful to see how the init(8) daemon
perceives the condition.
Example output:
foo
emits boing
emits blip
start on (starting A and (B or C var=2))
stop on (bar HELLO=world testing=123 or stopping wibble)
OPTIONS
- -e, --enumerate
-
If specified, rather than listing the precise start on and
stop on conditions, outputs the emits lines along with one
line for each event or job the CONF in question may be
started or stopped by if it were to become a job. If the start on
condition specifies a non-job event, this will be listed verbatim, whereas
for a job event, the name of the job as opposed to the event the
job emits will be listed.
The type of entity, its triggering event (if appropriate) and its full
environment is displayed in brackets following its name for clarity.
This option is useful for tools which generate graphs of relationships
between jobs and events. It is also instructive since it shows how the
init(8) daemon has parsed the job configuration file.
Example output (an analog of the default output format above):
foo
emits boing
emits blip
start on starting (job: A, env:)
start on B (job:, env:)
start on C (job:, env: var=2)
stop on bar (job:, env: HELLO=world testing=123)
stop on stopping (job: wibble, event: stopping, env:)
- check-config
- [OPTIONS] [CONF]
Considers all job configurations looking for jobs that cannot be started or
stopped, given the currently available job configurations. This is
achieved by considering the start on, stop on and emits stanzas for each
job configuration and identifying unreachable scenarios.
This option is useful for determining the impact of adding or removing job
configuration files.
Note that to use this command, it is necessary to ensure that all job
configuration files advertise the events they emit correctly.
If errors are identified, the name of the job configuration will be
displayed. Subsequent lines will show the failed conditions for the job
configuration, one per line. Condition lines begin with two spaces and are
followed with either "start on: " or "stop on: ", the
word "unknown", the type of entity that is not known and finally
its name.
Note that only job configurations that are logically in error (those with
unsatisfiable conditions) will be displayed. Note too that job
configurations that are syntactically invalid may trigger an error if they
would cause a condition to be in error.
Assuming job configuration file /etc/init/foo.conf contains the
following:
start on starting grape
stop on peach
The check-config command might display:
foo
start on: unknown job grape
stop on: unknown event peach
If any errors are detected, the exit code will be 1 (one). If all checks
pass, the exit code will be 0 (zero).
Note that for complex start on and stop on conditions, this command may give
what appears to be misleading output when an error condition is found
since all expressions in the failing condition that are in error will
generate error output. For example, if job configuration
/etc/init/bar.conf contains the following:
start on (A and (started B or (starting C or D)))
And only event A can be satisfied, the output will be:
bar
start on: unknown job B
start on: unknown job C
start on: unknown event D
OPTIONS
- -i [EVENTS], --ignore-events [EVENTS]
-
If specified, the argument should be a list of comma-separated events to
ignore when checking the job configuration files.
This option may be useful to ignore errors if a particular job configuration
file does not advertise it emits an event.
Note that internal events (such as startup(7) and starting(7))
are automatically ignored.
- -w, --warn
- If specified, treat any unknown jobs and events as errors.
- notify-disk-writeable
- Notify the init(8) daemon that the disk is now writeable. This
currently causes the init(8) daemon to flush its internal cache of
'early job' output data. An early job is any job which finishes
before the log disk becomes writeable. If job logging is not disabled,
this command should be called once the log disk becomes writeable to
ensure that output from all early jobs is flushed. If the data is written
successfully to disk, the internal cache is deleted.
- notify-dbus-address
- Notify the init(8) daemon of the D-Bus address it should use to
connect to.
This command is only permitted when running in User Session Mode. See
init(5) for further details.
- list-env
- [OPTIONS]
Display a lexicographically sorted list of all variables and their values in
a job environment table.
When run from within a job, this command will automatically query the
job-specific environment table; otherwise the global environment table
that is applied to all jobs when they first start is queried.
Note that the global job environment table comprises those variables already
set in the init(8) daemons environment at startup, the minimal set
of standard system variables added by the init(8) daemon, and any
variables set using set-env. See init(5) for further
details.
OPTIONS
- -g, --global
- Operate on the global job environment table. This option is implied when
not run from within a job.
- get-env
- [OPTIONS] VARIABLE
Display the value of the specified variable in a job environment table.
When run from within a job, this command will automatically query the
job-specific environment table; otherwise the global environment table
that is applied to all jobs when they first start is queried.
OPTIONS
- -g, --global
- Operate on the global job environment table. This option is implied when
not run from within a job.
- set-env
- [OPTIONS] VARIABLE[=VALUE]
Adds or updates a variable in a job environment table. Variables set in this
way will apply to all the subsequently-starting processes for a job.
This command is only permitted when running in User Session Mode. See
init(5) for further details.
OPTIONS
- -r, --retain
- If the specified variable is already set, do not modify it.
- -g, --global
- Operate on the global job environment table and all existing running job
environment tables. This option is implied when not run from within a job.
This is an advanced option whose use is discouraged since it can change the
environment of a job as it moves between different process stages (for
example between pre-start and the main process). See init(5)
for further details.
- unset-env
- [OPTIONS] VARIABLE
Remove the specified variable from a job environment table. If the variable
does not already exist in the table, no change will be made.
This command is only permitted when running in User Session Mode. See
init(5) for further details.
OPTIONS
- -r, --retain
- If the specified variable is already set, do not modify it.
- -g, --global
- Operate on the global job environment table and all existing running
jobenvironment tables. This option is implied when not run from within a
job.
This is an advanced option whose use is discouraged since it can change the
environment of a job as it moves between different process stages (for
example between pre-start and the main process). See init(5)
for further details.
- reset-env
- [OPTIONS]
Discards all changes make to a job environment table, setting it back to its
default set of variables and values.
This command is only permitted when running in User Session Mode. See
init(5) for further details.
Note that the effect of the Session Init process that manages the User
Session Mode restarting is equivalent to this command having been called.
OPTIONS
- -r, --retain
- If the specified variable is already set, do not modify it.
- -g, --global
- Operate on the global job environment table. This option is implied when
not run from within a job.
Note that unlike set-env and unset-env, this option does not
modify running job environment tables.
- list-sessions
-
List the pid of the Session Init process followed by the value of
UPSTART_SESSION in use for that session separted by a space
character. Session files relating to non-longer running Session Init
processes are considered 'stale' and are not listed (although when run
using --verbose, the full path of the stale session file is
displayed).
- usage
- JOB [KEY=VALUE]...
Show usage information for the named JOB. If the job specified does
not define the usage stanza, a blank usage will be displayed.
Example output for a job that specifies the usage stanza is shown
below. See init(5) for further details of the usage stanza:
Usage: tty DEV=ttyX - where X is console id
AUTHOR¶
Written by Scott James Remnant <
scott@netsplit.com> and James Hunt
<
james.hunt@canonical.com>
.
REPORTING BUGS¶
Report bugs at <
https://launchpad.net/upstart/+bugs>
COPYRIGHT¶
Copyright © 2009-2011 Canonical Ltd.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO¶
init(5) init(8) telinit(8) shutdown(8)