Ubuntu Manpage: systemd-run - Run programs in transient scope units, service units, or path-, socket-, or

Provided by: systemd_245.4-4ubuntu3.24_amd64

NAME

       systemd-run - Run programs in transient scope units, service units, or path-, socket-, or
       timer-triggered service units

SYNOPSIS

       systemd-run [OPTIONS...] COMMAND [ARGS...]

       systemd-run [OPTIONS...] [PATH OPTIONS...] {COMMAND} [ARGS...]

       systemd-run [OPTIONS...] [SOCKET OPTIONS...] {COMMAND} [ARGS...]

       systemd-run [OPTIONS...] [TIMER OPTIONS...] {COMMAND} [ARGS...]

DESCRIPTION

systemd-run may be used to create and start a transient .service or .scope unit and run
the specified COMMAND in it. It may also be used to create and start a transient .path,
.socket, or .timer unit, that activates a .service unit when elapsing.

If a command is run as transient service unit, it will be started and managed by the
service manager like any other service, and thus shows up in the output of systemctl
list-units like any other unit. It will run in a clean and detached execution environment,
with the service manager as its parent process. In this mode, systemd-run will start the
service asynchronously in the background and return after the command has begun execution
(unless --no-block or --wait are specified, see below).

If a command is run as transient scope unit, it will be executed by systemd-run itself as
parent process and will thus inherit the execution environment of the caller. However, the
processes of the command are managed by the service manager similar to normal services,
and will show up in the output of systemctl list-units. Execution in this case is
synchronous, and will return only when the command finishes. This mode is enabled via the
--scope switch (see below).

If a command is run with path, socket, or timer options such as --on-calendar= (see
below), a transient path, socket, or timer unit is created alongside the service unit for
the specified command. Only the transient path, socket, or timer unit is started
immediately, the transient service unit will be triggered by the path, socket, or timer
unit. If the --unit= option is specified, the COMMAND may be omitted. In this case,
systemd-run creates only a .path, .socket, or .timer unit that triggers the specified
unit.

By default, services created with systemd-run default to the simple type, see the
description of Type= in systemd.service(5) for details. Note that when this type is used
the service manager (and thus the systemd-run command) considers service start-up
successful as soon as the fork() for the main service process succeeded, i.e. before the
execve() is invoked, and thus even if the specified command cannot be started. Consider
using the exec service type (i.e. --property=Type=exec) to ensure that systemd-run
returns successfully only if the specified command line has been successfully started.

OPTIONS

The following options are understood:

--no-ask-password
Do not query the user for authentication for privileged operations.

--scope
Create a transient .scope unit instead of the default transient .service unit (see
above).

--unit=, -u
Use this unit name instead of an automatically generated one.

--property=, -p
Sets a property on the scope or service unit that is created. This option takes an
assignment in the same format as systemctl(1)'s set-property command.

--description=
Provide a description for the service, scope, path, socket, or timer unit. If not
specified, the command itself will be used as a description. See Description= in
systemd.unit(5).

--slice=
Make the new .service or .scope unit part of the specified slice, instead of
system.slice.

-r, --remain-after-exit
After the service process has terminated, keep the service around until it is
explicitly stopped. This is useful to collect runtime information about the service
after it finished running. Also see RemainAfterExit= in systemd.service(5).

--send-sighup
When terminating the scope or service unit, send a SIGHUP immediately after SIGTERM.
This is useful to indicate to shells and shell-like processes that the connection has
been severed. Also see SendSIGHUP= in systemd.kill(5).

--service-type=
Sets the service type. Also see Type= in systemd.service(5). This option has no effect
in conjunction with --scope. Defaults to simple.

--uid=, --gid=
Runs the service process under the specified UNIX user and group. Also see User= and
Group= in systemd.exec(5).

--nice=
Runs the service process with the specified nice level. Also see Nice= in
systemd.exec(5).

--working-directory=
Runs the service process with the specified working directory. Also see
WorkingDirectory= in systemd.exec(5).

--same-dir, -d
Similar to --working-directory= but uses the current working directory of the caller
for the service to execute.

-E NAME=VALUE, --setenv=NAME=VALUE
Runs the service process with the specified environment variable set. Also see
Environment= in systemd.exec(5).

--pty, -t
When invoking the command, the transient service connects its standard input, output
and error to the terminal systemd-run is invoked on, via a pseudo TTY device. This
allows running programs that expect interactive user input/output as services, such as
interactive command shells.

Note that machinectl(1)'s shell command is usually a better alternative for requesting
a new, interactive login session on the local host or a local container.

See below for details on how this switch combines with --pipe.

--pipe, -P
If specified, standard input, output, and error of the transient service are inherited
from the systemd-run command itself. This allows systemd-run to be used within shell
pipelines. Note that this mode is not suitable for interactive command shells and
similar, as the service process will not become a TTY controller when invoked on a
terminal. Use --pty instead in that case.

When both --pipe and --pty are used in combination the more appropriate option is
automatically determined and used. Specifically, when invoked with standard input,
output and error connected to a TTY --pty is used, and otherwise --pipe.

When this option is used the original file descriptors systemd-run receives are passed
to the service processes as-is. If the service runs with different privileges than
systemd-run, this means the service might not be able to re-open the passed file
descriptors, due to normal file descriptor access restrictions. If the invoked process
is a shell script that uses the echo "hello" > /dev/stderr construct for writing
messages to stderr, this might cause problems, as this only works if stderr can be
re-opened. To mitigate this use the construct echo "hello" >&2 instead, which is
mostly equivalent and avoids this pitfall.

--shell, -S
A shortcut for "--pty --same-dir --wait --collect --service-type=exec $SHELL", i.e.
requests an interactive shell in the current working directory, running in service
context, accessible with a single switch.

--quiet, -q
Suppresses additional informational output while running. This is particularly useful
in combination with --pty when it will suppress the initial message explaining how to
terminate the TTY connection.

--on-active=, --on-boot=, --on-startup=, --on-unit-active=, --on-unit-inactive=
Defines a monotonic timer relative to different starting points for starting the
specified command. See OnActiveSec=, OnBootSec=, OnStartupSec=, OnUnitActiveSec= and
OnUnitInactiveSec= in systemd.timer(5) for details. These options are shortcuts for
--timer-property= with the relevant properties. These options may not be combined with
--scope or --pty.

--on-calendar=
Defines a calendar timer for starting the specified command. See OnCalendar= in
systemd.timer(5). This option is a shortcut for --timer-property=OnCalendar=. This
option may not be combined with --scope or --pty.

--on-clock-change, --on-timezone-change
Defines a trigger based on system clock jumps or timezone changes for starting the
specified command. See OnClockChange= and OnTimezoneChange= in systemd.timer(5). These
options are shortcuts for --timer-property=OnClockChange=yes and
--timer-property=OnTimezoneChange=yes. These options may not be combined with --scope
or --pty.

--path-property=, --socket-property=, --timer-property=
Sets a property on the path, socket, or timer unit that is created. This option is
similar to --property= but applies to the transient path, socket, or timer unit rather
than the transient service unit created. This option takes an assignment in the same
format as systemctl(1)'s set-property command. These options may not be combined with
--scope or --pty.

--no-block
Do not synchronously wait for the unit start operation to finish. If this option is
not specified, the start request for the transient unit will be verified, enqueued and
systemd-run will wait until the unit's start-up is completed. By passing this
argument, it is only verified and enqueued. This option may not be combined with
--wait.

--wait
Synchronously wait for the transient service to terminate. If this option is
specified, the start request for the transient unit is verified, enqueued, and waited
for. Subsequently the invoked unit is monitored, and it is waited until it is
deactivated again (most likely because the specified command completed). On exit,
terse information about the unit's runtime is shown, including total runtime (as well
as CPU usage, if --property=CPUAccounting=1 was set) and the exit code and status of
the main process. This output may be suppressed with --quiet. This option may not be
combined with --no-block, --scope or the various path, socket, or timer options.

-G, --collect
Unload the transient unit after it completed, even if it failed. Normally, without
this option, all units that ran and failed are kept in memory until the user
explicitly resets their failure state with systemctl reset-failed or an equivalent
command. On the other hand, units that ran successfully are unloaded immediately. If
this option is turned on the "garbage collection" of units is more aggressive, and
unloads units regardless if they exited successfully or failed. This option is a
shortcut for --property=CollectMode=inactive-or-failed, see the explanation for
CollectMode= in systemd.unit(5) for further information.

--user
Talk to the service manager of the calling user, rather than the service manager of
the system.

--system
Talk to the service manager of the system. This is the implied default.

-H, --host=
Execute the operation remotely. Specify a hostname, or a username and hostname
separated by "@", to connect to. The hostname may optionally be suffixed by a port ssh
is listening on, separated by ":", and then a container name, separated by "/", which
connects directly to a specific container on the specified host. This will use SSH to
talk to the remote machine manager instance. Container names may be enumerated with
machinectl -H HOST. Put IPv6 addresses in brackets.

-M, --machine=
Execute operation on a local container. Specify a container name to connect to.

-h, --help
Print a short help text and exit.

--version
Print a short version string and exit.

All command line arguments after the first non-option argument become part of the command
line of the launched process. If a command is run as service unit, the first argument
needs to be an absolute program path.

EXIT STATUS

       On success, 0 is returned. If systemd-run failed to start the service, a non-zero return
       value will be returned. If systemd-run waits for the service to terminate, the return
       value will be propagated from the service. 0 will be returned on success, including all
       the cases where systemd considers a service to have exited cleanly, see the discussion of
       SuccessExitStatus= in systemd.service(5).

EXAMPLES

Example 1. Logging environment variables provided by systemd to services

# systemd-run env
Running as unit: run-19945.service
# journalctl -u run-19945.service
Sep 08 07:37:21 bupkis systemd[1]: Starting /usr/bin/env...
Sep 08 07:37:21 bupkis systemd[1]: Started /usr/bin/env.
Sep 08 07:37:21 bupkis env[19948]: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
Sep 08 07:37:21 bupkis env[19948]: LANG=en_US.UTF-8
Sep 08 07:37:21 bupkis env[19948]: BOOT_IMAGE=/vmlinuz-3.11.0-0.rc5.git6.2.fc20.x86_64

Example 2. Limiting resources available to a command

# systemd-run -p BlockIOWeight=10 updatedb

This command invokes the updatedb(8) tool, but lowers the block I/O weight for it to 10.
See systemd.resource-control(5) for more information on the BlockIOWeight= property.

Example 3. Running commands at a specified time

The following command will touch a file after 30 seconds.

# date; systemd-run --on-active=30 --timer-property=AccuracySec=100ms /bin/touch /tmp/foo
Mon Dec 8 20:44:24 KST 2014
Running as unit: run-71.timer
Will run service as unit: run-71.service
# journalctl -b -u run-71.timer
-- Logs begin at Fri 2014-12-05 19:09:21 KST, end at Mon 2014-12-08 20:44:54 KST. --
Dec 08 20:44:38 container systemd[1]: Starting /bin/touch /tmp/foo.
Dec 08 20:44:38 container systemd[1]: Started /bin/touch /tmp/foo.
# journalctl -b -u run-71.service
-- Logs begin at Fri 2014-12-05 19:09:21 KST, end at Mon 2014-12-08 20:44:54 KST. --
Dec 08 20:44:48 container systemd[1]: Starting /bin/touch /tmp/foo...
Dec 08 20:44:48 container systemd[1]: Started /bin/touch /tmp/foo.

Example 4. Allowing access to the tty

The following command invokes /bin/bash as a service passing its standard input, output
and error to the calling TTY.

# systemd-run -t --send-sighup /bin/bash

Example 5. Start screen as a user service

$ systemd-run --scope --user screen
Running scope as unit run-r14b0047ab6df45bfb45e7786cc839e76.scope.

$ screen -ls
There is a screen on:
492..laptop (Detached)
1 Socket in /var/run/screen/S-fatima.

This starts the screen process as a child of the systemd --user process that was started
by user@.service, in a scope unit. A systemd.scope(5) unit is used instead of a
systemd.service(5) unit, because screen will exit when detaching from the terminal, and a
service unit would be terminated. Running screen as a user unit has the advantage that it
is not part of the session scope. If KillUserProcesses=yes is configured in
logind.conf(5), the default, the session scope will be terminated when the user logs out
of that session.

The user@.service is started automatically when the user first logs in, and stays around
as long as at least one login session is open. After the user logs out of the last
session, user@.service and all services underneath it are terminated. This behavior is the
default, when "lingering" is not enabled for that user. Enabling lingering means that
user@.service is started automatically during boot, even if the user is not logged in, and
that the service is not terminated when the user logs out.

Enabling lingering allows the user to run processes without being logged in, for example
to allow screen to persist after the user logs out, even if the session scope is
terminated. In the default configuration, users can enable lingering for themselves:

$ loginctl enable-linger

Example 6. Return value

$ systemd-run --user --wait true
$ systemd-run --user --wait -p SuccessExitStatus=11 bash -c 'exit 11'
$ systemd-run --user --wait -p SuccessExitStatus=SIGUSR1 bash -c 'kill -SIGUSR1 $$$$'