Index · Directives systemd 223

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).

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 (".").

-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.

--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.

-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 transfer is complete, but no signatures are verified. If "signature" is specified, the checksum is verified and the images'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.

--dkr-index-url

Specifies the index server to use for downloading "dkr" images with the pull-dkr. Takes a "http://", "https://" URL.

--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.

-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 container images that can be started, use list-images (see below).

status NAME...

Show terse 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 an 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. 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, see below.

login NAME

Open an interactive terminal login session to a container. This will create a TTY connection to a specific container 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, which then asks for username and password. Use systemd-run(1) with the --machine= switch to invoke a single command, either interactively or in the background within a local container.

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. 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 an 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 subvolume images with this command. 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.

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 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 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 image name alters both the quota setting within the file system as well as the loopback file and file system size itself.

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.

pull-dkr REMOTE [NAME]

Downloads a "dkr" container image and makes it available locally. The remote name refers to a "dkr" container name. If omitted, the local machine name is derived from the "dkr" container name.

Image verification is not available for "dkr" containers, and thus --verify=no must always be specified with this command.

This command downloads all (missing) layers for the specified container and places them in read-only subvolumes in /var/lib/machines/. A writable snapshot of the newest layer is then created under the specified local machine name. To omit creation of this writable snapshot, pass "-" as local machine name.

The read-only layer subvolumes are prefixed with .dkr-, and thus not shown by list-images, unless --all is passed.

To specify the "dkr" index server to use for looking up the specified container, use --dkr-index-url=.

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 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.

Similar as with pull-tar, pull-raw the file system /var/lib/machines.raw is increased in size of necessary and appropriate. 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.

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, pull-dkr, 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.

  • A subvolume (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 it's --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 http://ftp.halifax.rwth-aachen.de/fedora/linux/releases/21/Cloud/Images/x86_64/Fedora-Cloud-Base-20141203-21.x86_64.raw.xz
# systemd-nspawn -M Fedora-Cloud-Base-20141203-21
# passwd
# exit
# machinectl start Fedora-Cloud-Base-20141203-21
# machinectl login Fedora-Cloud-Base-20141203-21

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. Download a Fedora "dkr" image

# machinectl pull-dkr --verify=no mattdm/fedora
# systemd-nspawn -M fedora

Downloads a "dkr" image and opens a shell in it. Note that the specified download command might require an index server to be specified with the "--dkr-index-url=".


Example 4. Exports a container image as tar file

# machinectl export-tar fedora myfedora.tar.xz

Exports the container "fedora" in an xz-compress tar file myfedora.tar.xz in the current directory.


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. Setting this to an empty string or the value "cat" is equivalent to passing --no-pager.

$SYSTEMD_LESS

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

See Also

systemd-machined.service(8), systemd-nspawn(1), systemd.special(7), tar(1), xz(1), gzip(1), bzip2(1)