*******
Classes
*******

This chapter document the classes that are provided by Belden CoreOS. Classes
provided by OpenEmbedded-Core are documented in the
:external:doc:`Yocto Reference Manual <ref-manual/classes>`.

.. _ref-classes-coreos-metadata-scm:
.. index:: coreos_metadata_scm.bbclass

``coreos_metadata_scm.bbclass``
===============================

The ``coreos_metadata_scm`` class is used inside the CoreOS distribution
configuration file to set the variables ``COREOS_METADATA_BRANCH`` and
``COREOS_METADATA_REVISION`` to the current Git branch and revision of the main
CoreOS repository.

The ``coreos_metadata_scm`` is automatically inherited if ``DISTRO`` is set to
``belden-coreos`` or to any distro based on ``belden-coreos``.

.. _ref-classes-coreos-image:
.. index:: coreos-image.bbclass

``coreos-image.bbclass``
========================

The ``coreos-image`` class provides common definitions for the
``coreos-image-*`` image recipes, such as support for additional
:extern:ref:`IMAGE_FEATURE <ref-features-image>`.

.. _ref-classes-coreos-sanity:
.. index:: coreos-sanity.class

``coreos-sanity.bbclass``
=========================

The ``coreos-sanity`` class is inherited inside the CoreOS layer
configuration file to add some sanity checks. Theses check ensure that the 
policies of CoreOS are followed.

Currently, this add check to ensure:
  - that the distro is based on CoreOS
  - that SystemD is used as ``INIT_MANAGER``
  - that glibc is used as the default C library