Image Description Elements

Note

This document provides a reference for the elements and attributes of the KIWI NG XML document in version 9.21.7

<image>

The toplevel of any KIWI NG image description

<image schemaversion="7.2" name="LimeJeOS-Leap-15.1">
    <!-- descendants -->
</image>

The image definition starts with an image tag and requires the schema format at version 7.2. The attribute name specifies the name of the image which is also used for the filenames created by KIWI. Because we don’t want spaces in filenames the name attribute must not have any spaces in its name.

The following optional attributes can be inserted in the image tag:

displayname

Allows setup of the boot menu title for the selected boot loader. So you can have suse-SLED-foo as the image name but a different name as the boot display name. Spaces are not allowed in the display name because it causes problems for some boot loaders and kiwi did not take the effort to separate the ones which can display them correctly from the ones which can’t

id

sets an identification number which appears as file /etc/ImageID within the image.

<description>

Provide an image identity.

<description type="system">
  <author>name</author>
  <contact>contact</contact>
  <specification>text</specification>
</description>

The mandatory description section contains information about the creator of this image description. The attribute type could be either of the value system which indicates this is a system image description or at value boot for custom kiwi boot image descriptions.

The following optional sub sections can be inserted below the description tag:

license

Specifies the license name which applies to this image description.

<preferences>

Setup image type and layout.

<preferences>
  <version>1.2.3</version>
  <packagemanager name="zypper"/>
  <type image="tbz"/>
</preferences>

The mandatory preferences section contains information about the supported image type(s), the used package manager, the version of this image, and further optional elements.

<preferences><version>

The mandatory image version must be a three-part version number of the format: Major.Minor.Release. In case of changes to the image description the following rules should apply:

  • For smaller image modifications that do not add or remove any new packages, only the release number is incremented. The XML description file(config.xml) remains unchanged.

  • For image changes that involve the addition or removal of packages the minor number is incremented and the release number is reset.

  • For image changes that changes the behavior or geometry of the image file the major number is incremented.

<preferences><packagemanager>

The mandatory packagemanager element specifies which package manager should be used to handle software packages. The packagemanager setup is connected to the distribution used to build the image. The following table shows which package manager is connected to which distributor:

Distributor

Package Manager

SUSE

zypper

RedHat

dnf

Debian Based

apt-get

Arch Linux

pacman

In general the specification of one preferences section is sufficient. However, it’s possible to specify multiple preferences sections and distinguish between the sections via the profiles attribute.

In combination with the above the preferences element supports the following optional elements:

<preferences><rpm-locale-filtering>

locale-filtering can be set to “true” or “false”. If set to “true” it sets the install_lang macro for RPM based installations to the RPM configured locale list. This results in language specific files to become filtered out by rpm if they don’t match the configured list.

<preferences>
  <rpm-locale-filtering>true</rpm-locale-filtering>
</preferences>

Note

It depends on the individual package design if the install_lang macro contents apply to the package or not.

<preferences><rpm-check-signatures>

Specifies whether package signatures should be checked or not

<preferences>
  <rpm-check-signatures>true</rpm-check-signatures>
</preferences>

<preferences><rpm-excludedocs>

Specifies whether files marked as documentation should be skipped during installation

<preferences>
  <rpm-excludedocs>true</rpm-excludedocs>
</preferences>

<preferences><keytable>

Specifies the name of the console keymap to use. The value corresponds to a map file in /usr/share/kbd/keymaps/xkb.

<preferences>
  <keytable>us</keytable>
</preferences>

<preferences><timezone>

Specifies the time zone. Available time zones are located in the /usr/share/zoneinfo directory. Specify the attribute value relative to /usr/share/zoneinfo. For example, specify Europe/Berlin for /usr/share/zoneinfo/Europe/Berlin.

<preferences>
  <keytable>Europe/Berlin</keytable>
</preferences>

<preferences><locale>

Specifies the name of the UTF-8 locale to use, which defines the contents of the RC_LANG system environment variable used in the image and to run the custom scripts specified as part of the KIWI NG image description. Please note only UTF-8 locales are supported here which also means that the encoding must not be part of the locale information. This means you need to specify the locale using the 4-digit name like the following example: en_US or en_US,de_DE

<preferences>
  <locale>en_US</locale>
</preferences>

<preferences><bootsplash-theme>

Specifies the name of the plymouth bootsplash theme to use

<preferences>
  <bootsplash-theme>bgrt</bootsplash-theme>
</preferences>

<preferences><bootloader-theme>

Specifies the name of the bootloader theme to use if that used bootloader has theme support.

<preferences>
  <bootloader-theme>openSUSE</bootloader-theme>
</preferences>

Along with the version and the packagemanager at least one image type element must be specified to indicate which image type should be build.

<preferences><type>

At least one type element must be configured. It is possible to specify multiple type elements in a preferences block. To set a given type description as the default image use the boolean attribute primary and set its value to true:

<preferences>
  <type image="typename" primary="true"/>
</preferences>

The image type to be created is determined by the value of the image attribute. The following list describes the supported types and possible values of the image attribute:

image=”tbz”

A simple tar archive image. The tbz type packs the contents of the image root tree into a xz compressed tarball.

image=”btrfs|ext2|ext3|ext4|squashfs|xfs”

A filesystem image. The image root tree data is packed into a filesystem image of the given type. An image of that type can be loop mounted and accessed according to the capabiities of the selected filesystem.

image=”iso”

An iso image which can be dumped on a CD/DVD or USB stick and boots off from this media without interfering with other system storage components. A useful pocket system for testing and demo and debugging purposes.

image=”vmx”

An image representing the system disk, useful for cloud frameworks like Amazon EC2, Google Compute Engine or Microsoft Azure.

image=”oem”

An image representing an expandable system disk. This means after deployment the system can resize itself to the new disk geometry. The resize operation is configurable as part of the image description and an installation image for CD/DVD, USB stick and Network deployment can be created in addition.

image=”docker”

An archive image suitable for the docker container engine. The image can be loaded via the docker load command and works within the scope of the container engine

image=”oci”

An archive image that builds a container matching the OCI (Open Container Interface) standard. The container should be able to run with any oci compliant container engine.

image=”appx”

An archive image suitable for the Windows Subsystem For Linux container engine. The image can be loaded From a Windows System that has support for WSL activated.

image=”kis”

An optional root filesystem image associated with a kernel and initrd. The use case for this component image type is highly customizable. Many different deployment strategies are possible.

For completion of a type description, there could be several other optional attributes and child elements. The type element supports a plethora of optional attributes, some of these are only relevant for certain build types and will be covered in extra chapters that describes the individual image types more detailed. Certain attributes are however useful for nearly all build types and will be covered next:

bootpartition=”true|false”:

Boolean parameter notifying KIWI NG whether an extra boot partition should be used or not (the default depends on the current layout). This will override KIWI NG’s default layout.

btrfs_quota_groups=”true|false”:

Boolean parameter to activate filesystem quotas if the filesystem is btrfs. By default quotas are inactive.

btrfs_root_is_snapshot=”true|false”:

Boolean parameter that tells KIWI NG to install the system into a btrfs snapshot. The snapshot layout is compatible with snapper. By default snapshots are turned off.

btrfs_root_is_readonly_snapshot=”true|false”:

Boolean parameter notifying KIWI NG that the btrfs root filesystem snapshot has to made read-only. if this option is set to true, the root filesystem snapshot it will be turned into read-only mode, once all data has been placed to it. The option is only effective if btrfs_root_is_snapshot is also set to true. By default the root filesystem snapshot is writable.

compressed=”true|false”:

Specifies whether the image output file should be compressed or not. This option is only used for filesystem only images or for the pxe or cpio types.

editbootconfig=”file_path”:

Specifies the path to a script which is called right before the bootloader is installed. The script runs relative to the directory which contains the image structure.

editbootinstall=”file_path”:

Specifies the path to a script which is called right after the bootloader is installed. The script runs relative to the directory which contains the image structure.

filesystem=”btrfs|ext2|ext3|ext4|squashfs|xfs”

The root filesystem

firmware=”efi|uefi”

Specifies the boot firmware of the appliance, supported options are: bios, ec2, efi, uefi, ofw and opal. This attribute is used to differentiate the image according to the firmware which boots up the system. It mostly impacts the disk layout and the partition table type. By default bios is used on x86, ofw on PowerPC and efi on ARM.

force_mbr=”true|false”:

Boolean parameter to force the usage of a MBR partition table even if the system would default to GPT. This is occasionally required on ARM systems that use a EFI partition layout but which must not be stored in a GPT. Note that forcing a MBR partition table incurs limitations with respect to the number of available partitions and their sizes.

fsmountoptions=”option_string”:

Specifies the filesystem mount options which are passed via the -o flag to mount and are included in /etc/fstab.

fscreateoptions=”option_string”:

Specifies the filesystem options used to create the filesystem. In KIWI NG the filesystem utility to create a filesystem is called without any custom options. The default options are filesystem specific and are provided along with the package that provides the filesystem utility. For the Linux ext[234] filesystem, the default options can be found in the /etc/mke2fs.conf file. Other filesystems provides this differently and documents information about options and their defaults in the respective manual page, e.g man mke2fs. With the fscreateoptions attribute it’s possible to directly influence how the filesystem will be created. The options provided as a string are passed to the command that creates the filesystem without any further validation by KIWI NG. For example, to turn off the journal on creation of an ext4 filesystem the following option would be required:

<preferences>
  <type fscreateoptions="-O ^has_journal"/>
</preferences>
kernelcmdline=”string”:

Additional kernel parameters passed to the kernel by the bootloader.

luks=”passphrase”:

Supplying a value will trigger the encryption of the partitions using the LUKS extension and using the provided string as the password. Note that the password must be entered when booting the appliance!

target_blocksize=”number”

Specifies the image blocksize in bytes which has to match the logical blocksize of the target storage device. By default 512 Bytes is used, which works on many disks. You can obtain the blocksize from the SSZ column in the output of the following command:

blockdev --report $DEVICE

The following sections shows the supported child elements of the type element including references to their usage in a detailed type setup:

<preferences><type><bootloader>

Used to describe the bootloader setup in vmx or oem disk image types. For details see: Setting up the Bootloader of the Image

<preferences><type><containerconfig>

Used to describe the container configuration metadata in docker or wsl image types. For details see: Build a Docker Container Image and: Build a WSL Container Image

<preferences><type><vagrantconfig>

Used to describe vagrant configuration metadata in vmx disk image that is being used as a vagrant box. For details see: Image Description for Vagrant

<preferences><type><systemdisk>

Used to describe the geometry, partitions and volumes, in a vmx or oem disk image. For details see: Custom Disk Volumes

<preferences><type><oemconfig>

Used to customize the deployment process in an oem disk image. For details see: OEM Customization

<preferences><type><size>

Used to customize the size of the resulting disk image in a vmx or oem image. For details see: Modifying the Size of the Image

<preferences><type><machine>

Used to customize the virtual machine configuration which describes the components of an emulated hardware. For details see: Customizing the Virtual Machine

<repository>

Setup software sources for the image.

<repository>
  <source path="uri"/>
</repository>

The mandatory repository element specifies the location and type of a repository to be used by the package manager as a package installation source. KIWI NG supports apt, dnf, pacman and zypper as package managers, specified with the packagemanager element. The repository element has the following optional attributes:

alias=”name”

Specifies an alternative name for the configured repository. If the attribute is not specified KIWI NG will generate a random alias name for the repository.

components=”name”

Used for Debian (apt) based repositories only. Specifies the component name that should be used from the repository. By default the main component is used

distribution=”name”

Used for Debian (apt) based repositories only. Specifies the distribution name to be used on call of debootstrap

imageonly=”true|false”

Specifies whether or not this repository should be configured in the resulting image without using it at build time. By default the value is set to false

repository_gpgcheck=”true|false”

Specifies whether or not this specific repository is configured to to run repository signature validation. If not set, no value is appended into the repository configuration file. If set the relevant key information needs to be provided on the KIWI NG commandline using the --signing-key option

imageinclude=”true|false”

Specifies whether the given repository should be configured as a repository in the image or not. The default behavior is that repositories used to build an image are not configured as a repository inside the image. This feature allows you to change the behavior by setting the value to true.

Note

Scope of repository uri’s

The repository is configured in the image according to the source path as specified with the path attribute of the source element. Therefore, if the path is not a fully qualified URL, you may need to adjust the repository file in the image to accommodate the expected location. It is recommended that you use the alias attribute in combination with the imageinclude attribute to avoid having unpredictable random names assigned to the repository you wish to include in the image.

password=”string”

Specifies a password for the given repository. The password attribute must be used in combination with the username attribute. Dependent on the repository location this information may not be used.

username=”name”

Specifies a user name for the given repository. The username attribute must be used in combination with the password attribute. Dependent on the repository location this information may not be used.

prefer-license=”true|false”

The repository providing this attribute will be used primarily to install the license tarball if found on that repository. If no repository with a preferred license attribute exists, the search happens over all repositories. It’s not guaranteed in that case that the search order follows the repository order like they are written into the XML description.

priority=”number”

Specifies the repository priority for this given repository. Priority values are treated differently by different package managers. Repository priorities allow the package management system to disambiguate packages that may be contained in more than one of the configured repositories. The zypper package manager for example prefers packages from a repository with a lower priority over packages from a repository with higher priority values. The value 99 means “no priority is set”. For other package managers please refer to the individual documentation about repository priorities.

sourcetype=”baseurl|metalink|mirrorlist”

Specifies the source type of the repository path. Depending on if the source path is a simple url or a pointer to a metadata file or mirror list, the configured package manager needs to be setup appropriately. By default the source is expected to be a simple repository baseurl.

<repository><source>

The location of a repository is specified by the path attribute of the mandatory source child element:

<repository alias="kiwi">
  <source path="obs://Virtualization:Appliances:Builder/openSUSE_Leap_15.1"/>
</repository>

The location specification may include the %arch macro which will expand to the architecture of the image building host. The value for the path attribute may begin with any of the following location indicators:

  • dir:///local/path An absolute path to a directory accessible through the local file system.

  • ftp://<ftp://> A ftp protocol based network location.

  • http://<http://> A http protocol based network location.

  • https://<https://> A https protocol based network location.

    Note

    https repositories

    When specifying a https location for a repository it is generally necessary to include the openssl certificates and a cracklib word dictionary as package entries in the bootstrap section of the image configuration. The names of the packages to include are individual to the used distribution. On SUSE systems as one example this would be openssl-certs and cracklib-dict-full

  • iso://<iso://> An absolute path to an .iso file accessible via the local file system. KIWI NG will loop mount the the .iso file to a temporary directory with a generated name. The generated path is provided to the specified package manager as a directory based repository location.

  • obs://Open:Build:Service:Project:Name A reference to a project in the Open Build Service (OBS). KIWI NG translates the given project path into a remote url at which the given project hosts the packages.

  • obsrepositories:/ A placeholder for the Open Build Service (OBS) to indicate that all repositories are taken from the project configuration in OBS.

<packages>

Setup software components to be installed in the image.

<packages type="type"/>

The mandatory packages element specifies the setup of a packages group for the given type. The value of the type attribute specifies at which state in the build process the packages group gets handled, supported values are as follows:

type=”bootstrap”

Bootstrap packages, list of packages to be installed first into a new (empty) root tree. The packages list the required components to support a chroot environment from which further software components can be installed

type=”image”

Image packages, list of packages to be installed as part of a chroot operation inside of the new root tree.

type=”uninstall|delete”

Packages to be uninstalled or deleted. For further details see Uninstall System Packages

type=”image_type_name”

Packages to be installed for the given image type name. For example if set to type=”iso”, the packages in this group will only be installed if the iso image type is build.

The packages element must contain at least one child element of the following list to provide specific configuration information for the specified packages group:

<packages><package>

<packages type="image"/>
  <package name="name" arch="arch"/>
</packages>

The package element installs the given package name. The optional arch attribute can be used to limit the installation of the package to the host architecture from which KIWI NG is called. The arch attribute is also available in all of the following elements.

<packages><namedCollection>

<packages type="image" patternType="onlyRequired">
  <namedCollection name="base"/>
</packages>

The namedCollection element is used to install a number of packages grouped together under a name. This is a feature of the individual distribution and used in the implementation of the KIWI NG package manager backend. At the moment collections are only supported for SUSE and RedHat based distributions. The optional patternType attribute is used to control the behavior of the dependency resolution of the package collection. onlyRequired installs only the collection and its required packages. plusRecommended installs the collection, any of its required packages and any recommended packages.

Note

Collections on SUSE

On SUSE based distributions collections are names patterns and are just simple packages. To get the names of the patterns such that they can be used in a namedCollection type the following command: $ zypper patterns. If for some reason the collection name cannot be used it is also possible to add the name of the package that provides the collection as part of a package element. To get the names of the pattern packages type the following command: $ zypper search patterns. By convention all packages that starts with the name “patterns-” are representing a pattern package.

Note

Collections on RedHat

On RedHat based distributions collections are named groups and are extra metadata. To get the names of these groups type the following command: $ dnf group list. Please note that group names are allowed to contain whitespace characters.

<packages><archive>

<packages type="image"/>
  <archive name="name"/>
</packages>

The archive element takes the name attribute and looks up the given name as file on the system. If specified relative KIWI NG looks up the name in the image description directory. The archive is installed using the tar program. Thus the file name is expected to be a tar archive. The compression of the archive is detected automatically by the tar program.

<packages><ignore>

<packages type="image"/>
  <ignore name="name"/>
</packages>

The ignore element instructs the used package manager to ignore the given package name at installation time. Please note whether or not the package can be ignored is up to the package manager. Packages that are hard required by other packages in the install procedure cannot be ignored and the package manager will simply ignore the request.

<packages><product>

<packages type="image">
  <product name="name"/>
</packages>

The product element instructs the used package manager to install the given product. What installation of a product means is up to the package manager and also distribution specific. This feature currently only works on SUSE based distributions

<users>

Setup image users.

<users>
  <user
    name="user"
    groups="group_list"
    home="dir"
    id="number"
    password="text"
    pwdformat="encrypted|plain"
    realname="name"
    shell="path"
  />
</users>

The optional users element contains the user setup KIWI NG should create in the system. At least one user child element must be specified as part of the users element. Multiple user elements may be specified.

Each user element represents a specific user that is added or modified. The following attributes are mandatory:

name=”name”:

the UNIX username

home=”path”:

The path to the user’s home directory

Additionally, the following optional attributes can be specified:

groups=”group_a,group_b”:

A comma separated list of UNIX groups. The first element of the list is used as the user’s primary group. The remaining elements are appended to the user’s supplementary groups. When no groups are assigned then the system’s default primary group will be used.

id=”number”:

The numeric user id of this account.

pwdformat=”plain|encrypted”:

The format in which password is provided. The default if not specified is encrypted.

password=”string”

The password for this user account. It can be provided either in cleartext form or encrypted. An encrypted password can be created using openssl as follows:

$ openssl passwd -1 -salt xyz PASSWORD

It is also possible to specify the password as a non encrypted string by using the pwdformat attribute and setting it’s value to plain. KIWI NG will then encrypt the password prior to the user being added to the system.

Warning

plain text passwords

We do not recommend plain passwords as they will be readable in the image configuration in plain text

All specified users and groups will be created if they do not already exist. The defined users will be part of the group(s) specified with the groups attribute or belong to the default group as configured in the system. If specified the first entry in the groups list is used as the login group.

<profiles>

Manage image namespace(s).

<profiles>
  <profile name="name" description="text"/>
</profiles>

The optional profiles section lets you maintain one image description while allowing for variation of other sections that are included. A separate profile element must be specified for each variation. The profile child element, which has name and description attributes, specifies an alias name used to mark sections as belonging to a profile, and a short description explaining what this profile does.

For example to mark a set of packages as belonging to a profile, simply annotate them with the profiles attribute as shown below:

<packages type="image" profiles="profile_name">
  <package name="name"/>
</packages>

It is also possible to mark sections as belonging to multiple profiles by separating the names in the profiles attribute with a comma:

<packages type="image" profiles="profile_A,profile_B">
  <package name="name"/>
</packages>

If a section tag does not have a profiles attribute, it is globally present in the configuration. If global sections and profiled sections contains the same sub-sections, the profiled sections will overwrite the global sections in the order of the provided profiles. For a better overview of the result configuration when profiles are used we recommend to put data that applies in any case to non profiled (global) sections and only extend those global sections with profiled data. For example:

<preferences>
  <version>1.2.3</version>
  <packagemanager name="zypper"/>
</preferences>

<preferences profiles="vmx_qcow_format">
  <type image="vmx" filesystem="ext4" format="qcow2"/>
</preferences>

<preferences profiles="vmx_vmdk_format">
  <type image="vmx" filesystem="ext4" format="vmdk"/>
</preferences>

The above example configures two version of the same vmx type. One builds a disk in qcow2 format the other builds a disk in vmdk format. The global preferences section without a profile assigned will be used in any case and defines those preferences settings that are common to any build process. A user can select both profiles at a time but that will result in building the disk format that is specified last because one is overwriting the other.

Use of one or more profile(s) during image generation is triggered by the use of the --profile command line argument. multiple profiles can be selected by passing this option multiple times.