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
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.
--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.
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.
-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 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=
--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.
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.
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).
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. 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 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 theSHA256SUMS 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.
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-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.
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. 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
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
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).
$SYSTEMD_PAGERSECURE
Takes a boolean argument. When true, the
"secure" mode of the pager is enabled; if false, disabled. If
$SYSTEMD_PAGERSECURE is not set at all, 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). In secure mode,
LESSSECURE=1 will be set when invoking the pager, and the pager shall
disable commands that open or create new files or start new subprocesses. When
$SYSTEMD_PAGERSECURE is not set at all, pagers which are not known to
implement secure mode will not be used. (Currently only
less(1)
implements secure mode.)
Note: when commands are invoked with elevated privileges, for
example under sudo(8) or pkexec(1), care must be taken to
ensure that unintended interactive features are not enabled.
"Secure" mode for the pager may be enabled automatically as
describe above. Setting SYSTEMD_PAGERSECURE=0 or not removing it from
the inherited environment allows the user to invoke arbitrary commands. Note
that if the $SYSTEMD_PAGER or $PAGER variables are to be
honoured, $SYSTEMD_PAGERSECURE must be set too. It might be
reasonable to completly disable the pager using --no-pager
instead.