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3.8 KiB
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99 lines
3.8 KiB
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=======================
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About OpenStack-Ansible
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=======================
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OpenStack-Ansible (OSA) uses the `Ansible <https://www.ansible.com/how-ansible-works>`_
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IT automation engine to deploy an OpenStack environment on Ubuntu, with CentOS and
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openSUSE currently in Beta release.
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For isolation and ease of maintenance, you can install OpenStack components
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into Linux containers (LXC).
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Why choose OpenStack-Ansible?
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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* Supports the major Linux distributions Ubuntu, CentOS (WIP) and OpenSUSE
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(WIP).
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* Supports the major CPU architectures x86, ppc64, s390x (WIP).
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* Offers automation for upgrades between major OpenStack releases.
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* Uses OpenStack defaults for each of the project roles, and provides
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extra wiring and optimised configuration when combining projects
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together.
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* Does not implement its own DSL, and uses wherever possible Ansible
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directly. All the experience acquired using Ansible can be used in
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openstack-ansible, and the other way around.
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* You like to use reliable, proven technology. We try to run OpenStack
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with a minimum amount of packages that are not provided by distributions
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or the OpenStack community. Less dependencies and distribution tested
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software make the project more reliable.
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* You want to be able to select how to deploy on your hardware: deploy
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partially on metal, fully on metal, or fully in machine containers.
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When **not** to choose OpenStack-Ansible?
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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* If your company is already invested with other configuration management
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systems, Puppet or Chef, and does not want to use Ansible we recommend
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re-using your knowledge and experimenting with a different
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OpenStack deployment project.
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* You want to deploy OpenStack with 100% application containers.
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We currently support machine containers, with lxc and we will support
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*systemd-nspawn* in the future (WIP). If you want to go 100% Docker,
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there are other projects in the OpenStack community that can
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help you.
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Ansible
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~~~~~~~
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Ansible provides an automation platform to simplify system and application
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deployment. Ansible manages systems by using Secure Shell (SSH)
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instead of unique protocols that require remote daemons or agents.
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Ansible uses playbooks written in the YAML language for orchestration.
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For more information, see `Ansible - Intro to
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Playbooks <http://docs.ansible.com/playbooks_intro.html>`_.
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This guide refers to the following types of hosts:
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* `Deployment host`, which runs the Ansible playbooks
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* `Target hosts`, where Ansible installs OpenStack services and infrastructure
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components
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Linux containers (LXC)
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~~~~~~~~~~~~~~~~~~~~~~
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Containers provide operating-system level virtualization by enhancing
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the concept of ``chroot`` environments. Containers isolate resources and file
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systems for a particular group of processes without the overhead and
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complexity of virtual machines. They access the same kernel, devices,
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and file systems on the underlying host and provide a thin operational
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layer built around a set of rules.
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The LXC project implements operating-system-level
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virtualization on Linux by using kernel namespaces, and it includes the
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following features:
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* Resource isolation including CPU, memory, block I/O, and network, by
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using ``cgroups``
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* Selective connectivity to physical and virtual network devices on the
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underlying physical host
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* Support for a variety of backing stores, including Logical Volume Manager
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(LVM)
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* Built on a foundation of stable Linux technologies with an active
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development and support community
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Installation workflow
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~~~~~~~~~~~~~~~~~~~~~
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The following diagram shows the general workflow of an OpenStack-Ansible
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installation.
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.. figure:: figures/installation-workflow-overview.png
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:width: 100%
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#. :ref:`deployment-host`
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#. :ref:`target-hosts`
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#. :ref:`configure`
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#. :ref:`run-playbooks`
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#. :ref:`verify-operation`
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