Ubuntu Manpage: machinectl - Control the systemd machine manager

Provided by: systemd-container_245.4-4ubuntu3.24_amd64

NAME

       machinectl - Control the systemd machine manager

SYNOPSIS

       machinectl [OPTIONS...] {COMMAND} [NAME...]

DESCRIPTION

       machinectl may be used to introspect and control the state of the systemd(1) virtual machine and
       container registration manager systemd-machined.service(8).

       machinectl may be used to execute operations on machines and images. Machines in this sense are
       considered running instances of:

       •   Virtual Machines (VMs) that virtualize hardware to run full operating system (OS) instances
           (including their kernels) in a virtualized environment on top of the host OS.

       •   Containers that share the hardware and OS kernel with the host OS, in order to run OS userspace
           instances on top the host OS.

       •   The host system itself.

       Machines are identified by names that follow the same rules as UNIX and DNS host names. For details, see
       below.

       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:

       •   Directory trees containing an OS, including the top-level directories /usr, /etc, and so on.

       •   btrfs subvolumes containing OS trees, similar to regular directory trees.

       •   Binary "raw" disk image files containing MBR or GPT partition tables and Linux file systems.

       •   Similarly, block devices containing MBR or GPT partition tables and file systems.

       •   The file system tree of the host OS itself.

COMMANDS

The following commands are understood:

Machine Commands
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.

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.

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.

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.

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.

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 similar 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).

When using the shell command without arguments, (thus invoking the executed shell or command on the
local host), it 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 and well-defined state. It will be tracked in a new utmp, login, audit, security and
keyring session, 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 for acquiring an interactive shell, similar to
machinectl shell. In general, systemd-run is preferable for scripting purposes. However, note that
systemd-run might require higher privileges than machinectl shell.

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,
similar to the effect of systemctl enable or systemctl disable on the service name.

poweroff NAME...
Power off one or more containers. This will trigger a reboot by sending SIGRTMIN+4 to the container's
init process, which causes systemd-compatible init systems to shut down cleanly. Use stop as alias
for poweroff. This operation does not work on containers that do not run a systemd(1)-compatible init
system, such as sysvinit. Use terminate (see below) to immediately terminate a container or VM,
without cleanly shutting it down.

reboot NAME...
Reboot one or more containers. This will trigger a reboot by sending 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.

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.

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-who= to
select which process to kill. Use --signal= to select the signal to send.

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 ready-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.

copy-to NAME PATH [PATH]
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).

copy-from NAME PATH [PATH]
Copies files or directories from a container into the host system. Takes a container name, followed
by the source path in the container the destination path on the host. If the destination path is
omitted, the same as the source path is used.

Image Commands
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.

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.

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.

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 host name, 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.

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.

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.

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.

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.

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 machinectl pull-tar or machinectl 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.

Image Transfer Commands
pull-tar URL [NAME]
Downloads a .tar container image from the specified URL, and makes it available under the specified
local machine name. The URL must be of type "http://" or "https://", and must refer to a .tar,
.tar.gz, .tar.xz or .tar.bz2 archive file. If the local machine name is omitted, it is automatically
derived from the last component of the URL, with its suffix removed.

The image is verified before it is made available, unless --verify=no is specified. Verification is
done either via an inline signed file with the name of the image and the suffix .sha256 or via
separate SHA256SUMS and SHA256SUMS.gpg files. The signature files need to be made available on the
same web server, under the same URL as the .tar file. With --verify=checksum, only the SHA256
checksum for the file is verified, based on the .sha256 suffixed file or the SHA256SUMS file. With
--verify=signature, the sha checksum file is first verified with the inline signature in the .sha256
file or the detached GPG signature file SHA256SUMS.gpg. The public key for this verification step
needs to be available in /usr/lib/systemd/import-pubring.gpg or /etc/systemd/import-pubring.gpg.

The container image will be downloaded and stored in a read-only subvolume in /var/lib/machines/ that
is named after the specified URL and its HTTP etag. A writable snapshot is then taken from this
subvolume, and named after the specified local name. This behavior ensures that creating multiple
container instances of the same URL is efficient, as multiple downloads are not necessary. In order
to create only the read-only image, and avoid creating its writable snapshot, specify "-" as local
machine name.

Note that the read-only subvolume is prefixed with .tar-, and is thus not shown by list-images,
unless --all is passed.

Note that pressing C-c during execution of this command will not abort the download. Use
cancel-transfer, described below.

pull-raw URL [NAME]
Downloads a .raw container or VM disk image from the specified URL, and makes it available under the
specified local machine name. The URL must be of type "http://" or "https://". The container image
must either be a .qcow2 or raw disk image, optionally compressed as .gz, .xz, or .bz2. If the local
machine name is omitted, it is automatically derived from the last component of the URL, with its
suffix removed.

Image verification is identical for raw and tar images (see above).

If the downloaded image is in .qcow2 format it is converted into a raw image file before it is made
available.

Downloaded images of this type will be placed as read-only .raw file in /var/lib/machines/. A local,
writable (reflinked) copy is then made under the specified local machine name. To omit creation of
the local, writable copy pass "-" as local machine name.

Similar to the behavior of pull-tar, the read-only image is prefixed with .raw-, and thus not shown
by list-images, unless --all is passed.

Note that pressing C-c during execution of this command will not abort the download. Use
cancel-transfer, described below.

import-tar FILE [NAME], import-raw FILE [NAME]
Imports a TAR or RAW container or VM image, and places it under the specified name in
/var/lib/machines/. When import-tar is used, the file specified as the first argument should be a tar
archive, possibly compressed with xz, gzip or bzip2. It will then be unpacked into its own subvolume
in /var/lib/machines. When import-raw is used, the file should be a qcow2 or raw disk image, possibly
compressed with xz, gzip or bzip2. If the second argument (the resulting image name) is not
specified, it is automatically derived from the file name. If the filename is passed as "-", the
image is read from standard input, in which case the second argument is mandatory.

Optionally, the --read-only switch may be used to create a read-only container or VM image. No
cryptographic validation is done when importing the images.

Much like image downloads, ongoing imports may be listed with list-transfers and aborted with
cancel-transfer.

import-fs DIRECTORY [NAME]
Imports a container image stored in a local directory into /var/lib/machines/, operates similar to
import-tar or import-raw, but the first argument is the source directory. If supported, this command
will create btrfs snapshot or subvolume for the new image.

export-tar NAME [FILE], export-raw NAME [FILE]
Exports a TAR or RAW container or VM image and stores it in the specified file. The first parameter
should be a VM or container image name. The second parameter should be a file path the TAR or RAW
image is written to. If the path ends in ".gz", the file is compressed with gzip, if it ends in
".xz", with xz, and if it ends in ".bz2", with bzip2. If the path ends in neither, the file is left
uncompressed. If the second argument is missing, the image is written to standard output. The
compression may also be explicitly selected with the --format= switch. This is in particular useful
if the second parameter is left unspecified.

Much like image downloads and imports, ongoing exports may be listed with list-transfers and aborted
with cancel-transfer.

Note that, currently, only directory and subvolume images may be exported as TAR images, and only raw
disk images as RAW images.

list-transfers
Shows a list of container or VM image downloads, imports and exports that are currently in progress.

cancel-transfer ID...
Aborts a download, import or export of the container or VM image with the specified ID. To list
ongoing transfers and their IDs, use list-transfers.

OPTIONS

The following options are understood:

-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.

-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.

--value
When printing properties with show, only print the value, and skip the property name and "=".

-l, --full
Do not ellipsize process tree entries or table. This implies --max-addresses=full.

--kill-who=
When used with kill, choose which processes to kill. Must be one of leader, or all to select whether
to kill only the leader process of the machine or all processes of the machine. If omitted, defaults
to all.

-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.

--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).

-E NAME=VALUE, --setenv=NAME=VALUE
When used with the shell command, sets an environment variable to pass to the executed shell. Takes
an environment variable name and value, separated by "=". This switch may be used multiple times to
set multiple environment variables. Note that this switch is not supported for the login command (see
below).

--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.

--read-only
When used with bind, creates a read-only bind mount.

When used with clone, import-raw or import-tar a read-only container or VM image is created.

-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.

-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".

--verify=
When downloading a container or VM image, specify whether the image shall be verified before it is
made available. Takes one of "no", "checksum" and "signature". If "no", no verification is done. If
"checksum" is specified, the download is checked for integrity after the transfer is complete, but no
signatures are verified. If "signature" is specified, the checksum is verified and the image's
signature is checked against a local keyring of trustable vendors. It is strongly recommended to set
this option to "signature" if the server and protocol support this. Defaults to "signature".

--force
When downloading a container or VM image, and a local copy by the specified local machine name
already exists, delete it first and replace it by the newly downloaded image.

--format=
When used with the export-tar or export-raw commands, specifies the compression format to use for the
resulting file. Takes one of "uncompressed", "xz", "gzip", "bzip2". By default, the format is
determined automatically from the image file name passed.

--max-addresses=
When used with the list-machines command, limits the number of ip addresses output for every machine.
Defaults to 1. All addresses can be requested with "all" as argument to --max-addresses=. If the
argument to --max-addresses= is less than the actual number of addresses, "..."follows the last
address.

-q, --quiet
Suppresses additional informational output while running.

-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=
Connect to systemd-machined.service(8) running in a local container, to perform the specified
operation within the container.

--no-pager
Do not pipe output into a pager.

--no-legend
Do not print the legend, i.e. column headers and the footer with hints.

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

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

--version
Print a short version string and exit.

MACHINE AND IMAGE NAMES

The machinectl tool operates on machines and images whose names must be chosen following strict rules.
Machine names must be suitable for use as host names 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 and underscore. The maximum
length of a machine name is 64 characters.

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.

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.

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.

FILES AND DIRECTORIES

       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.

       Note that some image operations are only supported, efficient or atomic on btrfs file systems.

       Disk images are understood by systemd-nspawn(1) and machinectl in three formats:

       •   A simple directory tree, containing the files and directories of the container to boot.

       •   Subvolumes (on btrfs file systems), which are similar to the simple directories, described above.
           However, they have additional benefits, such as efficient cloning and quota reporting.

       •   "Raw" disk images, i.e. binary images of disks with a GPT or MBR partition table. Images of this type
           are regular files with the suffix ".raw".

       See systemd-nspawn(1) for more information on image formats, in particular its --directory= and --image=
       options.

EXAMPLES

Example 1. Download an Ubuntu image and open a shell in it

# machinectl pull-tar https://cloud-images.ubuntu.com/trusty/current/trusty-server-cloudimg-amd64-root.tar.gz
# systemd-nspawn -M trusty-server-cloudimg-amd64-root

This downloads and verifies the specified .tar image, and then uses systemd-nspawn(1) to open a shell in
it.

Example 2. Download a Fedora image, set a root password in it, start it as service

# machinectl pull-raw --verify=no https://dl.fedoraproject.org/pub/fedora/linux/releases/27/CloudImages/x86_64/images/Fedora-Cloud-Base-27-1.6.x86_64.raw.xz
# systemd-nspawn -M Fedora-Cloud-Base-27-1.6.x86_64
# passwd
# exit
# machinectl start Fedora-Cloud-Base-27-1.6.x86_64
# machinectl login Fedora-Cloud-Base-27-1.6.x86_64

This downloads the specified .raw image with verification disabled. Then, a shell is opened in it and a
root password is set. Afterwards the shell is left, and the machine started as system service. With the
last command a login prompt into the container is requested.

Example 3. Exports a container image as tar file

# machinectl export-tar fedora myfedora.tar.xz

Exports the container "fedora" as an xz-compressed tar file myfedora.tar.xz into the current directory.

Example 4. Create a new shell session

# machinectl shell --uid=lennart

This creates a new shell session on the local host for the user ID "lennart", in a su(1)-like fashion.

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

ENVIRONMENT

$SYSTEMD_PAGER
Pager to use when --no-pager is not given; overrides $PAGER. If neither $SYSTEMD_PAGER nor $PAGER are
set, a set of well-known pager implementations are tried in turn, including less(1) and more(1),
until one is found. If no pager implementation is discovered no pager is invoked. Setting this
environment variable to an empty string or the value "cat" is equivalent to passing --no-pager.

$SYSTEMD_LESS
Override the options passed to less (by default "FRSXMK").

Users might want to change two options in particular:

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.

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.

See less(1) for more discussion.

$SYSTEMD_LESSCHARSET
Override the charset passed to less (by default "utf-8", if the invoking terminal is determined to be
UTF-8 compatible).

$SYSTEMD_COLORS
The value must be a boolean. Controls whether colorized output should be generated. This can be
specified to override the decision that systemd makes based on $TERM and what the console is
connected to.

$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.