machinectl

systemd
Developer Lennart Poettering lennart@poettering.net
machinectl 1
machinectl Control the systemd machine manager
`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.

## 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 the source directory on the host. 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 behaviour 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 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 behaviour 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

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.

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.

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=`.

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.

## See Also

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