| MACHINECTL(1) | machinectl | MACHINECTL(1) |
.SH "NAME" machinectl - Control the systemd machine manager
.SH "SYNOPSIS"
.HP 264u
machinectl
[OPTIONS...]
{COMMAND}
[NAME...]
.SH "DESCRIPTION"
.PP machinectl may be used to introspect and control the state of the
systemd(1) virtual machine and container registration manager
systemd-machined.service(8).
.PP machinectl may be used to execute operations on machines and
images. Machines in this sense are considered running instances of:
.PP Machines are identified by names that follow the same rules as UNIX and
DNS hostnames. For details, see below.
.PP Machines are instantiated from disk or file system images that
frequently — but not necessarily — carry the
same name as machines running from them. Images in this sense may be:
.PP Images may be downloaded, imported and exported via the
importctl(1) tool.
.SH "COMMANDS"
.PP The following commands are understood:
.SS "Machine Commands"
.PP list
List currently running (online) virtual machines and containers. To enumerate
machine images that can be started, use list-images (see below). Note
that this command hides the special .host machine by default. Use the
--all switch to show it.
Added in version 206.
.RE
.PP status NAME...
Show runtime status information about one or more virtual machines and
containers, followed by the most recent log data from the journal. This
function is intended to generate human-readable output. If you are looking
for computer-parsable output, use show instead. Note that the log
data shown is reported by the virtual machine or container manager, and
frequently contains console output of the machine, but not necessarily
journal contents of the machine itself.
Added in version 206.
.RE
.PP show [NAME...]
Show properties of one or more registered virtual machines or containers or
the manager itself. If no argument is specified, properties of the manager
will be shown. If a NAME is specified, properties of this virtual machine or
container are shown. By default, empty properties are suppressed. Use
--all to show those too. To select specific properties to show, use
--property=. This command is intended to be used whenever
computer-parsable output is required, and does not print the control group
tree or journal entries. Use status if you are looking for formatted
human-readable output.
Added in version 206.
.RE
.PP start NAME...
Start a container as a system service, using systemd-nspawn(1). This
starts systemd-nspawn@.service, instantiated for the specified machine name,
similar to the effect of systemctl start on the service name.
systemd-nspawn looks for a container image by the specified name in
/var/lib/machines/ (and other search paths, see below) and runs it. Use
list-images (see below) for listing available container images to
start.
Note that systemd-machined.service(8) also interfaces with a variety
of other container and VM managers, systemd-nspawn is just one
implementation of it. Most of the commands available in machinectl
may be used on containers or VMs controlled by other managers, not just
systemd-nspawn. Starting VMs and container images on those managers
requires manager-specific tools.
To interactively start a container on the command line with full access to
the container's console, please invoke systemd-nspawn directly. To
stop a running container use machinectl poweroff.
Added in version 219.
.RE
.PP login [NAME]
Open an interactive terminal login session in a container or on the local
host. If an argument is supplied, it refers to the container machine to
connect to. If none is specified, or the container name is specified as the
empty string, or the special machine name .host (see below) is specified,
the connection is made to the local host instead. This will create a TTY
connection to a specific container or the local host and asks for the
execution of a getty on it. Note that this is only supported for containers
running systemd(1) as init system.
This command will open a full login prompt on the container or the local
host, which then asks for username and password. Use shell (see
below) or systemd-run(1) with the --machine= switch to
directly invoke a single command, either interactively or in the
background.
Added in version 209.
.RE
.PP shell [[NAME@]NAME [PATH
[ARGUMENTS...]]]
Open an interactive shell session in a container or on the local host. The
first argument refers to the container machine to connect to. If none is
specified, or the machine name is specified as the empty string, or the
special machine name .host (see below) is specified, the connection is made
to the local host instead. This works similarly to login, but
immediately invokes a user process. This command runs the specified
executable with the specified arguments, or the default shell for the user
if none is specified, or /bin/sh if no default shell is found. By default,
--uid=, or by prefixing the machine name with a username and an @
character, a different user may be selected. Use --setenv= to set
environment variables for the executed process.
Note that machinectl shell does not propagate the exit code/status of
the invoked shell process. Use systemd-run instead if that
information is required (see below).
Using the shell command without arguments (thus invoking the executed
shell or command on the local host), is in many ways similar to a
su(1) session, but, unlike su, completely isolates the new
session from the originating session, so that it shares no process or
session properties and is in a clean well-defined state. It will be tracked
in a new utmp, login, audit, security, and keyring sessions, and will not
inherit any environment variables or resource limits, among other
properties.
Note that systemd-run(1) with its --machine= switch may be used
in place of the machinectl shell command, and allows non-interactive
operation, more detailed and low-level configuration of the invoked unit, as
well as access to runtime and exit code/status information of the invoked
shell process. In particular, use systemd-run's --wait switch
to propagate exit status information of the invoked process. Use
systemd-run's --pty switch to acquire an interactive shell,
similarly to machinectl shell. In general, systemd-run is
preferable for scripting purposes. However, note that systemd-run
might require higher privileges than machinectl shell.
Added in version 225.
.RE
.PP enable NAME..., disable NAME...
Enable or disable a container as a system service to start at system boot,
using systemd-nspawn(1). This enables or disables
systemd-nspawn@.service, instantiated for the specified machine name,
similarly to the effect of systemctl enable or systemctl
disable on the service name.
This command implicitly reloads the system manager configuration after
completing the operation. Note that this command does not implicitly start
or power off the containers that are being operated on. If this is desired,
combine the command with the --now switch.
Added in version 219.
.RE
.PP poweroff NAME...
Power off one or more machines. For VMs managed by systemd-vmspawn(1),
this sends an ACPI powerdown request via QMP. For containers, this sends
SIGRTMIN+4 to the container's init process, which causes systemd-compatible
init systems to shut down cleanly. This operation does not work on
containers that do not run a systemd(1)-compatible init system, such
as sysvinit. Use stop as alias for poweroff. Use
terminate (see below) to immediately terminate a machine without
cleanly shutting it down.
Added in version 212.
.RE
.PP reboot NAME...
Reboot one or more machines. For VMs managed by systemd-vmspawn(1),
this sends a system reset request via QMP. For containers, this sends SIGINT
to the container's init process, which is roughly equivalent to pressing
Ctrl+Alt+Del on a non-containerized system, and is compatible with
containers running any system manager. Use restart as alias for
reboot.
Added in version 209.
.RE
.PP pause NAME...
Pause one or more machines. For VMs managed by systemd-vmspawn(1),
this freezes vCPU execution at the hypervisor level — the guest
operating system is not notified and does not observe an ACPI suspend. From
the guest's perspective time simply stops until the machine is resumed with
resume.
Added in version 261.
.RE
.PP resume NAME...
Resume one or more previously paused machines. This restarts execution after
a pause.
Added in version 261.
.RE
.PP terminate NAME...
Immediately terminates a virtual machine or container, without cleanly
shutting it down. This kills all processes of the virtual machine or
container and deallocates all resources attached to that instance. Use
poweroff to issue a clean shutdown request.
Added in version 206.
.RE
.PP kill NAME...
Send a signal to one or more processes of the virtual machine or container.
This means processes as seen by the host, not the processes inside the
virtual machine or container. Use --kill-whom= to select which
process to kill. Use --signal= to select the signal to send.
Added in version 206.
.RE
.PP bind NAME PATH [PATH]
Bind mounts a file or directory from the host into the specified container.
The first path argument is the source file or directory on the host, the
second path argument is the destination file or directory in the container.
When the latter is omitted, the destination path in the container is the
same as the source path on the host. When combined with the
--read-only switch, a read-only bind mount is created. When combined
with the --mkdir switch, the destination path is first created before
the mount is applied. Note that this option is currently only supported for
systemd-nspawn(1) containers, and only if user namespacing
(--private-users) is not used. This command supports bind mounting
directories, regular files, device nodes, AF_UNIX socket nodes, as
well as FIFOs.
Added in version 219.
.RE
.PP bind-volume NAME SPEC
Acquire a storage volume from a storagectl(1) provider and attach it
to the running machine. SPEC is a string of the form
PROVIDER:VOLUME[:CONFIG][:K=V,...], identical in
grammar to the --bind-volume= argument of
systemd-vmspawn(1).
The attached volume is identified by the name PROVIDER:VOLUME
and may be detached at runtime via unbind-volume. Currently only
supported for systemd-vmspawn machines that expose an
io.systemd.MachineInstance control socket.
Added in version 261.
.RE
.PP unbind-volume NAME STORAGE-NAME
Detach a storage volume from the running machine. STORAGE-NAME is the
PROVIDER:VOLUME identifier that was specified at
bind-volume time. Volumes that were attached at machine startup (e.g.
via --bind-volume= on systemd-vmspawn(1)) cannot be detached
and will fail with io.systemd.MachineInstance.StorageImmutable.
Added in version 261.
.RE
.PP copy-to NAME PATH [PATH] --force
Copies files or directories from the host system into a running container.
Takes a container name, followed by the source path on the host and the
destination path in the container. If the destination path is omitted, the
same as the source path is used.
If host and container share the same user and group namespace, file ownership
by numeric user ID and group ID is preserved for the copy, otherwise all
files and directories in the copy will be owned by the root user and group
(UID/GID 0).
Added in version 219.
.RE
.PP copy-from NAME PATH [PATH] --force
Copies files or directories from a container into the host system. Takes a
container name, followed by the source path in the container and the
destination path on the host. If the destination path is omitted, the same
as the source path is used.
If host and container share the same user and group namespace, file ownership
by numeric user ID and group ID is preserved for the copy, otherwise all
files and directories in the copy will be owned by the root user and group
(UID/GID 0).
Added in version 219.
.RE
.SS "Image Commands"
.PP list-images
Show a list of locally installed container and VM images. This enumerates all
raw disk images and container directories and subvolumes in
/var/lib/machines/ (and other search paths, see below). Use start
(see above) to run a container off one of the listed images. Note that, by
default, containers whose name begins with a dot (.) are not shown. To show
these too, specify --all. Note that a special image .host always
implicitly exists and refers to the image the host itself is booted
from.
Added in version 219.
.RE
.PP image-status [NAME...]
Show terse status information about one or more container or VM images. This
function is intended to generate human-readable output. Use
show-image (see below) to generate computer-parsable output
instead.
Added in version 219.
.RE
.PP show-image [NAME...]
Show properties of one or more registered virtual machine or container
images, or the manager itself. If no argument is specified, properties of
the manager will be shown. If a NAME is specified, properties of this
virtual machine or container image are shown. By default, empty properties
are suppressed. Use --all to show those too. To select specific
properties to show, use --property=. This command is intended to be
used whenever computer-parsable output is required. Use image-status
if you are looking for formatted human-readable output.
Added in version 219.
.RE
.PP edit NAME|FILE
Edit the settings file of the specified machines. For the format of the
settings file, refer to systemd.nspawn(5). If an existing settings
file of the given machine cannot be found, edit automatically create
a new settings file from scratch under /etc/systemd/nspawn/.
Added in version 254.
.RE
.PP cat NAME|FILE
Show the settings file of the specified machines.
Added in version 254.
.RE
.PP clone NAME NAME
Clones a container or VM image. The arguments specify the name of the image
to clone and the name of the newly cloned image. Note that plain directory
container images are cloned into btrfs subvolume images with this command,
if the underlying file system supports this. Note that cloning a container
or VM image is optimized for file systems that support copy-on-write, and
might not be efficient on others, due to file system limitations.
Note that this command leaves hostname, machine ID and all other settings
that could identify the instance unmodified. The original image and the
cloned copy will hence share these credentials, and it might be necessary to
manually change them in the copy.
If combined with the --read-only switch a read-only cloned image is
created.
Added in version 219.
.RE
.PP rename NAME NAME
Renames a container or VM image. The arguments specify the name of the image
to rename and the new name of the image.
Added in version 219.
.RE
.PP read-only NAME [BOOL]
Marks or (unmarks) a container or VM image read-only. Takes a VM or container
image name, followed by a boolean as arguments. If the boolean is omitted,
positive is implied, i.e. the image is marked read-only.
Added in version 219.
.RE
.PP remove NAME...
Removes one or more container or VM images. The special image .host, which
refers to the host's own directory tree, may not be removed.
Added in version 219.
.RE
.PP set-limit [NAME] BYTES
Sets the maximum size in bytes that a specific container or VM image, or all
images, may grow up to on disk (disk quota). Takes either one or two
parameters. The first, optional parameter refers to a container or VM image
name. If specified, the size limit of the specified image is changed. If
omitted, the overall size limit of the sum of all images stored locally is
changed. The final argument specifies the size limit in bytes, possibly
suffixed by the usual K, M, G, T units. If the size limit shall be disabled,
specify - as size.
Note that per-container size limits are only supported on btrfs file
systems.
Added in version 220.
.RE
.PP clean
Remove hidden VM or container images (or all). This command removes all
hidden machine images from /var/lib/machines/, i.e. those whose name begins
with a dot. Use machinectl list-images --all to see a list of all
machine images, including the hidden ones.
When combined with the --all switch removes all images, not just
hidden ones. This command effectively empties /var/lib/machines/.
Note that commands such as importctl pull-tar or importctl
pull-raw usually create hidden, read-only, unmodified machine images
from the downloaded image first, before cloning a writable working copy of
it, in order to avoid duplicate downloads in case of images that are reused
multiple times. Use machinectl clean to remove old, hidden images
created this way.
Added in version 230.
.RE
.SH "OPTIONS"
.PP The following options are understood:
.PP -p, --property=
When showing machine or image properties, limit the output to certain
properties as specified by the argument. If not specified, all set
properties are shown. The argument should be a property name, such as Name.
If specified more than once, all properties with the specified names are
shown.
Added in version 206.
.RE
.PP --value
When printing properties with show, only print the value, and skip the
property name and =.
Added in version 230.
.RE
.PP -P
Equivalent to --value --property=, i.e. shows the value of the
property without the property name or =. Note that using -P once will
also affect all properties listed with -p/--property=.
Added in version 256.
.RE
.PP -a, --all
When showing machine or image properties, show all properties regardless of
whether they are set or not.
When listing VM or container images, do not suppress images beginning in a
dot character (.).
When cleaning VM or container images, remove all images, not just hidden
ones.
Added in version 206.
.RE
.PP -l, --full
Do not ellipsize process tree entries or table. This implies
--max-addresses=full.
Added in version 206.
.RE
.PP --kill-whom=
When used with kill, choose which processes to kill. Must be one of
leader, supervisor, or all to select whether to kill
only the leader process of the machine, the supervisor process of the
machine, or all processes of the machine. If omitted, defaults to
all.
Added in version 206.
.RE
.PP -s, --signal=
When used with kill, choose which signal to send to selected
processes. Must be one of the well-known signal specifiers such as
SIGTERM, SIGINT or SIGSTOP. If omitted, defaults to
SIGTERM.
The special value help will list the known values and the program will exit
immediately, and the special value list will list known values along with
the numerical signal numbers and the program will exit immediately.
.RE
.PP --uid=
When used with the shell command, chooses the user ID to open the
interactive shell session as. If the argument to the shell command
also specifies a user name, this option is ignored. If the name is not
specified in either way, root will be used by default. Note that this switch
is not supported for the login command (see below).
Added in version 225.
.RE
.PP -E NAME[=VALUE],
--setenv=NAME[=VALUE]
When used with the shell command, sets an environment variable for the
executed shell. This option may be used more than once to set multiple
variables. When = and VALUE are omitted, the value of the variable
with the same name in the program environment will be used.
Note that this option is not supported for the login command.
Added in version 230.
.RE
.PP --mkdir
When used with bind, creates the destination file or directory before
applying the bind mount. Note that even though the name of this option
suggests that it is suitable only for directories, this option also creates
the destination file node to mount over if the object to mount is not a
directory, but a regular file, device node, socket or FIFO.
Added in version 219.
.RE
.PP --read-only
When used with bind, creates a read-only bind mount.
When used with clone a read-only container or VM image is created.
Added in version 219.
.RE
.PP -n, --lines=
When used with status, controls the number of journal lines to show,
counting from the most recent ones. Takes a positive integer argument.
Defaults to 10.
Added in version 219.
.RE
.PP -o, --output=
When used with status, controls the formatting of the journal entries
that are shown. For the available choices, see journalctl(1).
Defaults to short.
Added in version 219.
.RE
.PP --runner=nspawn|vmspawn
When operating on machines choose whether to use systemd-nspawn(1) or
systemd-vmspawn(1). By default systemd-nspawn(1) is used.
Added in version 256.
.RE
.PP -V
-V is a shorthand for --runner=vmspawn.
Added in version 256.
.RE
.PP --now
When used with enable or disable, the containers will also be
started or powered off. The start or poweroff operation is only carried out
when the respective enable or disable operation has been successful.
Added in version 253.
.RE
.PP --force
Replace target file when copying files.
Added in version 219.
.RE
.PP --max-addresses=
When used with the list-machines command, limits the number of IP
addresses shown for every machine. Defaults to 1. All addresses can be
requested with all. If the limit is 0, the address column is not shown.
Otherwise, if the machine has more addresses than shown, ... follows the
last address.
Added in version 232.
.RE
.PP -q, --quiet
Suppresses additional informational output while running.
Added in version 236.
.RE
.PP -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.
.RE
.PP -M, --machine=
Connect to systemd-machined.service(8) running in a local container,
to perform the specified operation within the container.
Added in version 235.
.RE
.PP --no-pager
Do not pipe output into a pager.
.RE
.PP --no-legend
Do not print the legend, i.e. column headers and the footer with hints.
.RE
.PP --no-ask-password
Do not query the user for authentication for privileged operations.
.RE
.PP -h, --help
Print a short help text and exit.
.RE
.PP --version
Print a short version string and exit.
.RE
.SH "MACHINE AND IMAGE NAMES"
.PP The machinectl tool operates on machines and images whose names
must be chosen following strict rules. Machine names must be suitable for
use as hostnames following a conservative subset of DNS and UNIX/Linux
semantics. Specifically, they must consist of one or more non-empty label
strings, separated by dots. No leading or trailing dots are allowed. No
sequences of multiple dots are allowed. The label strings may only consist
of alphanumeric characters as well as the dash. The maximum length of a
machine name is 64 characters.
.PP A special machine with the name .host refers to the running host system
itself. This is useful for execution operations or inspecting the host
system as well. Note that machinectl list will not show this special
machine unless the --all switch is specified.
.PP Requirements on image names are less strict, however, they must be valid
UTF-8, must be suitable as file names (hence not be the single or double
dot, and not include a slash), and may not contain control characters. Since
many operations search for an image by the name of a requested machine, it
is recommended to name images in the same strict fashion as machines.
.PP A special image with the name .host refers to the image of the running
host system. It hence conceptually maps to the special .host machine name
described above. Note that machinectl list-images will not show this
special image either, unless --all is specified.
.SH "FILES AND DIRECTORIES"
.PP Machine images are preferably stored in /var/lib/machines/, but are also
searched for in /usr/local/lib/machines/ and /usr/lib/machines/. For
compatibility reasons, the directory /var/lib/container/ is searched, too.
Note that images stored below /usr/ are always considered read-only. It is
possible to symlink machines images from other directories into
/var/lib/machines/ to make them available for control with
machinectl.
.PP Note that some image operations are only supported, efficient or atomic
on btrfs file systems.
.PP Disk images are understood by systemd-nspawn(1) and
machinectl in three formats:
.PP See systemd-nspawn(1) for more information on image formats, in
particular its --directory= and --image= options.
.SH "EXAMPLES"
.PP Example 1. Download an Ubuntu RAW image, set a root
password in it, start it as a service
# importctl pull-raw -mN \
https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64-disk-kvm.img \
jammy # systemd-firstboot --image=/var/lib/machines/jammy.raw --prompt-root-password --force # machinectl start jammy # machinectl login jammy
.PP This downloads the specified .raw image and makes it available under the
local name jammy. Then, a root password is set with
systemd-firstboot(1). Afterwards the machine is started as system
service. With the last command a login prompt into the container is
requested.
.SH "EXIT STATUS"
.PP On success, 0 is returned, a non-zero failure code otherwise.
.SH "ENVIRONMENT"
.PP $SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a higher log level,
i.e. less important ones, will be suppressed). Takes a comma-separated list
of values. A value may be either one of (in order of decreasing importance)
emerg, alert, crit, err, warning,
notice, info, debug, or an integer in the range 0...7.
See syslog(3) for more information. Each value may optionally be
prefixed with one of console, syslog, kmsg or
journal followed by a colon to set the maximum log level for that
specific log target (e.g. SYSTEMD_LOG_LEVEL=debug,console:info
specifies to log at debug level except when logging to the console which
should be at info level). Note that the global maximum log level takes
priority over any per target maximum log levels.
.RE
.PP $SYSTEMD_LOG_COLOR
A boolean. If true, messages written to the tty will be colored according to
priority.
This setting is only useful when messages are written directly to the
terminal, because journalctl(1) and other tools that display logs
will color messages based on the log level on their own.
.RE
.PP $SYSTEMD_LOG_TIME
A boolean. If true, console log messages will be prefixed with a
timestamp.
This setting is only useful when messages are written directly to the
terminal or a file, because journalctl(1) and other tools that
display logs will attach timestamps based on the entry metadata on their
own.
.RE
.PP $SYSTEMD_LOG_LOCATION
A boolean. If true, messages will be prefixed with a filename and line number
in the source code where the message originates.
Note that the log location is often attached as metadata to journal entries
anyway. Including it directly in the message text can nevertheless be
convenient when debugging programs.
.RE
.PP $SYSTEMD_LOG_TID
A boolean. If true, messages will be prefixed with the current numerical
thread ID (TID).
Note that the this information is attached as metadata to journal entries
anyway. Including it directly in the message text can nevertheless be
convenient when debugging programs.
.RE
.PP $SYSTEMD_LOG_TARGET
The destination for log messages. One of console (log to the attached
tty), console-prefixed (log to the attached tty but with prefixes
encoding the log level and "facility", see syslog(3),
kmsg (log to the kernel circular log buffer), journal (log to
the journal), journal-or-kmsg (log to the journal if available, and
to kmsg otherwise), auto (determine the appropriate log target
automatically, the default), null (disable log output).
.RE
.PP $SYSTEMD_LOG_RATELIMIT_KMSG
Whether to ratelimit kmsg or not. Takes a boolean. Defaults to true. If
disabled, systemd will not ratelimit messages written to kmsg.
.RE
.PP $SYSTEMD_PAGER, $PAGER
Pager to use when --no-pager is not given. $SYSTEMD_PAGER is
used if set; otherwise $PAGER is used. If neither
$SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager
implementations is tried in turn, including less(1) and
more(1), until one is found. If no pager implementation is
discovered, no pager is invoked. Setting those environment variables to an
empty string or the value cat is equivalent to passing
--no-pager.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER and
$PAGER can only be used to disable the pager (with cat or ), and are
otherwise ignored.
.RE
.PP $SYSTEMD_LESS
Override the options passed to less (by default FRSXMK).
Users might want to change two options in particular:
.PP K
This option instructs the pager to exit immediately when Ctrl+C is pressed.
To allow less to handle Ctrl+C itself to switch back to the pager
command prompt, unset this option.
If the value of $SYSTEMD_LESS does not include K, and the pager that
is invoked is less, Ctrl+C will be ignored by the executable, and
needs to be handled by the pager.
.RE
.PP X
This option instructs the pager to not send termcap initialization and
deinitialization strings to the terminal. It is set by default to allow
command output to remain visible in the terminal even after the pager exits.
Nevertheless, this prevents some pager functionality from working, in
particular paged output cannot be scrolled with the mouse.
.RE
.sp
Note that setting the regular $LESS environment variable has no effect
for less invocations by systemd tools.
See less(1) for more discussion.
.RE
.PP $SYSTEMD_LESSCHARSET
Override the charset passed to less (by default utf-8, if the invoking
terminal is determined to be UTF-8 compatible).
Note that setting the regular $LESSCHARSET environment variable has no
effect for less invocations by systemd tools.
.RE
.PP $SYSTEMD_PAGERSECURE
Common pager commands like less(1), in addition to "paging",
i.e. scrolling through the output, support opening of or writing to other
files and running arbitrary shell commands. When commands are invoked with
elevated privileges, for example under sudo(8) or pkexec(1),
the pager becomes a security boundary. Care must be taken that only programs
with strictly limited functionality are used as pagers, and unintended
interactive features like opening or creation of new files or starting of
subprocesses are not allowed. "Secure mode" for the pager may be
enabled as described below, if the pager supports that (most pagers
are not written in a way that takes this into consideration). It is
recommended to either explicitly enable "secure mode" or to
completely disable the pager using --no-pager or PAGER=cat
when allowing untrusted users to execute commands with elevated
privileges.
This option takes a boolean argument. When set to true, the "secure
mode" of the pager is enabled. In "secure mode",
LESSSECURE=1 will be set when invoking the pager, which instructs the
pager to disable commands that open or create new files or start new
subprocesses. Currently only less(1) is known to understand this
variable and implement "secure mode".
When set to false, no limitation is placed on the pager. Setting
SYSTEMD_PAGERSECURE=0 or not removing it from the inherited
environment may allow the user to invoke arbitrary commands.
When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to
automatically figure out if "secure mode" should be enabled and
whether the pager supports it. "Secure mode" is enabled if the
effective UID is not the same as the owner of the login session, see
geteuid(2) and sd_pid_get_owner_uid(3), or when running under
sudo(8) or similar tools ($SUDO_UID is set [1]). In those
cases, SYSTEMD_PAGERSECURE=1 will be set and pagers which are not
known to implement "secure mode" will not be used at all. Note
that this autodetection only covers the most common mechanisms to elevate
privileges and is intended as convenience. It is recommended to explicitly
set $SYSTEMD_PAGERSECURE or disable the pager.
Note that if the $SYSTEMD_PAGER or $PAGER variables are to be
honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must
be set too.
.RE
.PP $SYSTEMD_COLORS
Takes a boolean argument, or a special value. By default (unset),
systemd and related utilities will use colors in their output if
possible. If $COLORTERM is set to truecolor or 24bit, 24-bit colors
will be enabled, 256 colors otherwise, unless $NO_COLOR or
$TERM indicates colors are disabled.
.PP true
Same as unset, except that $NO_COLOR is ignored.
.RE
.PP false
The output will be monochrome.
.RE
.PP 16, 256, 24bit
Always use the base 16 ANSI colors, 256 colors, or 24 bit color,
respectively.
.RE
.PP auto-16, auto-256, auto-24bit
Use the given quantity of colours, subject to $TERM, and what the
console is connected to.
.RE
.sp
.RE
.PP $SYSTEMD_URLIFY
The value must be a boolean. Controls whether clickable links should be
generated in the output for terminal emulators supporting this. This can be
specified to override the decision that systemd makes based on
$TERM and other conditions.
.RE
.SH "SEE ALSO"
.PP systemd(1), systemd-machined.service(8),
systemd-nspawn(1), systemd.special(7), importctl(1),
tar(1), xz(1), gzip(1), bzip2(1),
zstd(1)
NOTES
- 1.
-
It is recommended for other tools to set and check $SUDO_UID as appropriate, treating it is a common interface.
| systemd 262.2 |