machinectl(1)
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 are considered: * Directory trees containing an OS, including its top-level directories /usr, /etc, and so on. * btrfs subvolumes containing OS trees, similar to normal directory trees. * Binary "raw" disk images containing MBR or GPT partition tables and Linux file system partitions. * The file system tree of the host OS itself.
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.
--no-ask-password
Do not query the user for authentication for privileged operations.
--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 directory before
applying the bind mount.
--read-only
When used with bind, applies 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. If multiple addresses are
to be written for a given machine, every address except the first
one is on a new line and is followed by "," if another address will
be output afterwards.
-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 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.
-M, --machine=
Execute operation on a local container. Specify a container name to
connect to.
--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.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
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 /bin/sh if none is specified. By default, opens a "root" shell,
but by using --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.
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) may be used in place of the shell command,
and allows more detailed, low-level configuration of the invoked
unit. However, it is frequently more privileged than the shell
command.
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 directory from the host into the specified container.
The first directory argument is the source directory on the host,
the second directory argument is the destination 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.
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.
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 btrfs file systems, 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. Also note that, if set-limit is invoked without an
image parameter, and /var/lib/machines is empty, and the directory
is not located on btrfs, a btrfs loopback file is implicitly
created as /var/lib/machines.raw with the given size, and mounted
to /var/lib/machines. The size of the loopback may later be
readjusted with set-limit, as well. If such a loopback-mounted
/var/lib/machines directory is used, set-limit without an image
name alters both the quota setting within the file system as well
as the loopback file and file system size itself.
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 via SHA256SUMS and
SHA256SUMS.gpg files that need to be made available on the same web
server, under the same URL as the .tar file, but with the last
component (the filename) of the URL replaced. With
--verify=checksum, only the SHA256 checksum for the file is
verified, based on the SHA256SUMS file. With --verify=signature,
the SHA256SUMS file is first verified with 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 file name is passed as "-", the
image is read from standard input, in which case the second
argument is mandatory.
Both pull-tar and pull-raw will resize /var/lib/machines.raw and
the filesystem therein as necessary. 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.
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-transfers 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.
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 many image operations are only supported, efficient or atomic on btrfs file systems. Due to this, if the pull-tar, pull-raw, import-tar, import-raw and set-limit commands notice that /var/lib/machines is empty and not located on btrfs, they will implicitly set up a loopback file /var/lib/machines.raw containing a btrfs file system that is mounted to /var/lib/machines. The size of this loopback file may be controlled dynamically with set-limit. 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/23/Cloud/x86_64/Images/Fedora-Cloud-Base-23-20151030.x86_64.raw.xz
# systemd-nspawn -M Fedora-Cloud-Base-23-20151030
# passwd
# exit
# machinectl start Fedora-Cloud-Base-23-20151030
# machinectl login Fedora-Cloud-Base-23-20151030
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").
$SYSTEMD_LESSCHARSET
Override the charset passed to less (by default "utf-8", if the
invoking terminal is determined to be UTF-8 compatible).
SEE ALSO
systemd-machined.service(8), systemd-nspawn(1), systemd.special(7), tar(1), xz(1), gzip(1), bzip2(1)
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