.. _self_contained: Building in a Self-Contained Environment ======================================== .. note:: **Abstract** Users building images with {kiwi} face problems if they want to build an image matching one of the following criteria: * build should happen as non root user. * build should happen on a host system distribution for which no {kiwi} packages exists. * build happens on an incompatible host system distribution compared to the target image distribution. For example building an apt/dpkg based system on an rpm based system. * run more than one build process at the same time on the same host. * run a build process for a different target architecture compared to the host architecture (Cross Arch Image Build) This document describes how to perform the build process in a self contained environment using fast booting virtual machines to address the issues listed above. The changes on the machine to become a build host will be reduced to the requirements of the {kiwi} `boxed plugin` Requirements ------------ Add the {kiwi} repo from the Open Build Service. For details see :ref:`installation-from-obs`. The following {kiwi} plugin needs to be installed on the build system: .. code:: bash $ sudo zypper in python3-kiwi_boxed_plugin Building with the boxbuild command ---------------------------------- The installation of the {kiwi} boxed plugin has registered a new kiwi command named `boxbuild`. The command implementation uses KVM as virtualization technology and runs the {kiwi} `build` command inside of a KVM controlled virtual machine. For running the build process in a virtual machine it's required to provide VM images that are suitable to perform this job. We call the VM images `boxes` and they contain kiwi itself as well as all other components needed to build appliances. Those boxes are hosted in the Open Build Service and are publicly available at the `Subprojects` tab in the: `Virtualization:Appliances:SelfContained `__ project. As a user you don't need to work with the boxes because this is all done by the plugin and provided as a service by the {kiwi} team. The `boxbuild` command knows where to fetch the box and also cares for an update of the box when it has changed. Building an image with the `boxbuild` command is similar to building with the `build` command. The plugin validates the given command call with the capabilities of the `build` command. Thus one part of the `boxbuild` command is exactly the same as with the `build` command. The separation between `boxbuild` and `build` options is done using the `--` separator like shown in the following example: .. code:: bash $ kiwi-ng --type iso system boxbuild --box leap -- \ --description kiwi/build-tests/{exc_description_disk} \ --set-repo {exc_repo_leap} \ --target-dir /tmp/myimage .. note:: The provided `--description` and `--target-dir` options are setup as shared folders between the host and the box. No other data will be shared with the host. Sharing Backends ---------------- As mentioned above, the `boxbuild` call shares the two host directories provided in `--description` and `--target-dir` with the box. To do this the following sharing backends are supported: ``--9p-sharing`` With QEMU's `9pfs` you can create virtual filesystem devices (virtio-9p-device) and expose them to the box. For more information see `9pfs `__. Using this sharing backend does not require any setup procedure from the user and is also the default for `boxbuild` ``--sshfs-sharing`` SSHFS is a FUSE-based filesystem client for mounting remote directories over a Secure Shell connection (SSH). In `boxbuild` this is used to mount directories from the host into the box. Because this runs through an SSH connection the host must allow connections from the box. If you plan to use `sshfs` add the following SSH public key to the :file:`~/.ssh/authorized_keys` file of the user which is expected to call `boxbuild` .. code:: bash echo "ssh-rsa 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 kiwi@boxbuild" >> ~/.ssh/authorized_keys The public key mentioned here is associated with an SSH key pair we provide in the pre-built box images. .. warning:: If the `sshfs` backend is used without the host trusting the box, the `boxbuild` call will become interactive at the time of the sshfs mount. In this case the user might be asked for a passphrase or depending on the host `sshd` setup the request will be declined and the boxbuild fails. ``--virtiofs-sharing`` QEMU virtio-fs shared file system daemon. Share a host directory tree with a box through a virtio-fs device. For more information see `virtiofs `__. Using this sharing backend does not require any setup procedure from the user .. warning:: virtiofs support was added but considered experimental and not yet stable across the distributions. Feedback welcome.