Build a WSL Container Image

KIWI NG can build WSL images using the appx utility. Make sure you have installed the package that provides the command on your build host.

Once the build host has the appx installed, the following image type setup is required in the XML description config.xml:

<type image="appx" metadata_path="/meta/data"/>

The /meta/data path specifies a path that provides additional information required for the WSL-DistroLauncher. This component consists out of a Windows(exe) executable file and an AppxManifest.xml file that references other files, like icons and resource configurations for the startup of the container under Windows.



Except for the root filesystem tarball KIWI NG is not responsible for providing the meta data required for the WSL-DistroLauncher. It is expected that the given metadata path contains all the needed information. Typically this information is delivered in a package provided by the distribution, and it is installed on the build host.

Setup of the WSL-DistroLauncher

The contents of the AppxManifest.xml is changed by KIWI NG if the containerconfig section is provided in the XML description. In the context of a WSL image, the following container configuration parameters are taken into account:

<containerconfig name="my-wsl-container">
    >Container Description Text</history>

All information provided here, including the entire section, is optional. If the information is not specified, the existing AppxManifest.xml is left untouched.


Specifies the name of a publisher organization. An appx container must to be signed off with a digital signature. If the image is build in the Open Build Service (OBS), this is done automatically. Outside of OBS, you must o make sure that the given publisher organization name matches the certificate used for signing.


Provides the name of the author and maintainer of this container.


Specifies an ID name for the container. The name must start with a letter, and only alphanumeric characters are allowed. KIWI NG doesn not validate the specified name string, because there is no common criteria for various the container architectures.


Specifies the version identification for the container. KIWI NG validates it against the Microsoft Package Version Numbering rules.


Specifies the binary file name of the launcher .exe file.


KIWI NG does not check the configuration in AppxManifest.xml ifor validity or completeness.

The following example shows how to build a WSL image based on openSUSE Tumbleweed:

  1. Check the example image descriptions, see Example Appliance Descriptions.

  2. Include the Virtualization/WSL repository to the list ((replace <DIST> with the desired distribution)):

    $ zypper addrepo<DIST> WSL
  3. Install fb-util-for-appx utility and the package that provides the WSL-DistroLauncher metadata. See the previous note on /meta/data.

    $ zypper in fb-util-for-appx DISTRO_APPX_METADATA_PACKAGE


    When building images with the Open Build Servic,e make sure to add the packages from the zypper command above to the project configuration via osc meta -e prjconf along with the line support: PACKAGE_NAME for each package that needs to be installed on the Open Build Service worker that runs the KIWI NG build process.

  4. Configure the image type:

    Add the following type and container configuration to kiwi/build-tests/x86/tumbleweed/test-image-wsl/

    <type image="appx" metadata_path="/meta/data">
        <containerconfig name="Tumbleweed">
            >Tumbleweed Appliance text based</history>


    If the configured metadata path does not exist, the build will fail. Furthermore, KIWI NG does not check whether the metadata is complete or is valid according to the requirements of the WSL-DistroLauncher

  5. Build the image with KIWI NG:

    $ sudo kiwi-ng system build \
        --description kiwi/build-tests/x86/tumbleweed/test-image-wsl \
        --set-repo \
        --target-dir /tmp/myimage

Testing the WSL image

For testing the image, you need a Windows 10 system. Before you proceed, enable the optional feature named Microsoft-Windows-Subsystem-Linux. For further details on how to setup the Windows machine, see: Windows Subsystem for Linux