Building Linux System Appliances
Note
This documentation covers KIWI Next Generation (KIWI NG) 10.2.0- the command line utility to build Linux system appliances. If you are using a KIWI NG schema version older than v74, upgrade the kiwi file as follows:
$ xsltproc /usr/share/kiwi/xsl_to_v74/update.xsl config.xml|*.kiwi
The Appliance Concept
An appliance is a ready to use image of an operating system including a pre-configured application for a specific use case. The appliance is provided as an image file and needs to be deployed to, or activated in the target system or service.
KIWI NG can create appliances in various forms: beside classical installation ISOs and images for virtual machines it can also build images that boot via PXE or Vagrant boxes.
In KIWI NG, the appliance is specified via a collection of human readable files
in a directory, also called the image description. At least one XML file
config.xml or .kiwi is required. In addition there may as
well be other files like scripts or configuration data.
Use Cases
The following list shows a selection of use cases for which an appliance is needed:
- Private and Public Clouds
Cloud environments are managed through an API provided by the cloud service provider. The classic way to install a machine is not possible in such an environment because there is no physical access to the machine. An appliance is needed to be registered with the cloud
- Custom Linux Distribution
Linux distributors provides their distribution based on a collection of packages and release them on an install media like a DVD or an USB stick. Typically a lot more software components exists for the distribution which are not part of the default installation media or the installation media comes with software and installation routines that are not matching your target audience. With an appliance made by KIWI NG you can create provide an installation media that matches custom criteria as needed by the customer and does not require extra post processing steps after the default installation method provided by the distributor.
- Live Systems
The ability to have a Linux OS that runs from a small storage device like a USB stick or a SD card is the swiss army knife of many system administrators. The creation of such a live system includes use of technologies that are not part of a standard installation process. An appliance builder is needed to create this sort of system
- Embedded Systems
Embedded Systems like the Raspberry Pi comes with limited hardware components. Their boot sequences often does not allow for classic installation methods through USB or DVD devices. Instead they boot through SD card slots or via the network. SoC (System on Chip) devices also tend to implement non standard boot methods which can only be implemented through custom OS appliances.
- And More
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