kiwi-el8/doc/source/overview.rst
Marcus Schäfer f6f77b3162
Fixup documentation for consistency
There is the legacy kiwi version and there is this kiwi(next generation).
From a documentation perspective there are several inconsistencies that
could confuse users. This commit makes the name for KIWI-NG consistent
across the entire documentation. At places where we point to older
documentation we use the term Legacy KIWI and a link to the documentation
that covers this part. All this is needed in preparation to cleanup the
documentation situation for the SUSE documentation but with respect to
the upstream doc sources, their layout and markup.
2020-02-19 18:01:14 +01:00

95 lines
3.2 KiB
ReStructuredText

.. _db_overview:
Overview
========
.. note:: **Abstract**
This document provides a conceptual overview about the steps
of creating an image with {kiwi}. It also explains the terminology
regarding the concept and process when building system images
with {kiwi} |version|.
.. toctree::
:maxdepth: 1
overview/workflow
Conceptual Overview
-------------------
A system image (usually called "image"), is a *complete installation* of a Linux
system within a file. The image represents an operation system and,
optionally, contains the "final" configuration.
{kiwi} creates images in a two step process:
1. The first step, the *prepare operation*, generates a so-called
*unpacked image tree* (directory) using the information provided in
the image description.
2. The second step, the *create operation*, creates the *packed image* or
*image* in the specified format based on the unpacked image and the
information provided in the configuration file.
The image creation process with {kiwi} is automated and does not require any
user interaction. The information required for the image creation process is
provided by the image description.
Terminology
-----------
Appliance
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.
Image
The result of a {kiwi} build process.
Image Description
Specification to define an appliance. The image description is a
collection of human readable files in a directory. At least one XML
file :file:`config.xml` or :file:`.kiwi` is required. In addition
there may be as well other files like scripts or configuration data.
These can be used to customize certain parts either of the {kiwi}
build process or of the initial start-up behavior of the image.
Overlay Files
A directory structure with files and subdirectories stored as part
of the Image Description. This directory structure is packaged as
a file :file:`root.tar.gz` or stored inside a directory named
:file:`root`. The content of the directory structure is copied on top of
the the existing file system (overlayed) of the appliance root.
This also includes permissions and attributes as a supplement.
{kiwi}
An OS appliance builder.
Virtualization Technology
Software simulated computer hardware. A virtual machine acts like
a real computer, but is separated from the physical hardware.
Within this documentation the QEMU virtualization system is
used. Another popular alternative is Virtualbox.
System Requirements
-------------------
To use and run {kiwi}, you need:
* A recent Linux distribution, see :ref:`supported-distributions` for
details. Alternatively a Linux distribution which supports the docker
container system, where {kiwi} can be run inside a container, see:
:ref:`container-building`
* Enough free disk space to build and store the image. We recommend a
minimum of 15GB.
* Python version 3.4 or higher
* Git (package ``git``) to clone a repository.
* Any virtualization technology to start the image. We recommend QEMU.