========
Overview
========

DevStack has evolved to support a large number of configuration options
and alternative platforms and support services. That evolution has grown
well beyond what was originally intended and the majority of
configuration combinations are rarely, if ever, tested. DevStack is not
a general OpenStack installer and was never meant to be everything to
everyone.

Below is a list of what is specifically is supported (read that as
"tested") going forward.

Supported Components
====================

Base OS
-------

*The OpenStack Technical Committee (TC) has defined the current CI
strategy to include the latest Ubuntu release and the latest RHEL
release.*

-  Ubuntu: current LTS release plus current development release
-  Fedora: current release plus previous release
-  RHEL/CentOS: current major release
-  Other OS platforms may continue to be included but the maintenance of
   those platforms shall not be assumed simply due to their presence.
   Having a listed point-of-contact for each additional OS will greatly
   increase its chance of being well-maintained.
-  Patches for Ubuntu and/or Fedora will not be held up due to
   side-effects on other OS platforms.

Databases
---------

*As packaged by the host OS*

-  MySQL

Queues
------

*As packaged by the host OS*

-  Rabbit

Web Server
----------

*As packaged by the host OS*

-  Apache

OpenStack Network
-----------------

-  Neutron: A basic configuration approximating the original FlatDHCP
   mode using linuxbridge or OpenVSwitch.

Services
--------

The default services configured by DevStack are Identity (keystone),
Object Storage (swift), Image Service (glance), Block Storage
(cinder), Compute (nova), Placement (placement),
Networking (neutron), Dashboard (horizon).

Additional services not included directly in DevStack can be tied in to
``stack.sh`` using the :doc:`plugin mechanism <plugins>` to call
scripts that perform the configuration and startup of the service.

Node Configurations
-------------------

-  single node
-  multi-node configurations as are tested by the gate