Heat

= OpenStack Orchestration =

The mission of the OpenStack Orchestration program is to create a human- and machine-accessible service for managing the entire lifecycle of infrastructure and applications within OpenStack clouds.

= Heat =

Heat is the main project in the OpenStack Orchestration program. It implements an orchestration engine to launch multiple composite cloud applications based on templates in the form of text files that can be treated like code. A native Heat template format is evolving, but Heat also endeavours to provide compatibility with the AWS CloudFormation template format, so that many existing CloudFormation templates can be launched on OpenStack. Heat provides both an OpenStack-native ReST API and a CloudFormation-compatible Query API.

Why ‘Heat’? It makes the clouds rise!

How it works

 * A Heat template describes the infrastructure for a cloud application in a text file that is readable and writable by humans, and can be checked into version control, diffed, &c.
 * Infrastructure resources that can be described include: servers, floating ips, volumes, security groups, users, etc.
 * Heat also provides an autoscaling service that integrates with Telemetry, so you can include a scaling group as a resource in a template.
 * Templates can also specify the relationships between resources (e.g. this volume is connected to this server). This enables Heat to call out to the OpenStack APIs to create all of your infrastructure in the correct order to completely launch your application.
 * Heat manages the whole lifecycle of the application - when you need to change your infrastructure, simply modify the template and use it to update your existing stack. Heat knows how to make the necessary changes. It will delete all of the resources when you are finished with the application, too.
 * Heat primarily manages infrastructure, but the templates integrate well with software configuration management tools such as Puppet and Chef. The Heat team is working on providing even better integration between infrastructure and software.

Architecture
Heat comprises a number of Python applications:

heat
The heat tool is a CLI which communicates with the heat-api to execute AWS CloudFormation APIs. Of course this is not required—developers could also use the Heat APIs directly.

heat-api
The heat-api component provides an OpenStack-native ReST API that processes API requests by sending them to the heat-engine over RPC.

heat-api-cfn
The heat-api-cfn component provides an AWS-style Query API that is compatible with AWS CloudFormation and processes API requests by sending them to the heat-engine over RPC.

heat-engine
The heat engine does the main work of orchestrating the launch of templates and providing events back to the API consumer.

Development

 * Source repository
 * Client source repository
 * Example templates
 * Bug/Feature tracker
 * Tarballs
 * Heat Plugin Developer Guide
 * Developer Process
 * Core Team
 * Code Review Dashboard

Getting Started Guides
There are getting started guides for several distributions in the Heat Documentation
 * The installation guides on http://docs.openstack.org
 * Getting Started With Heat on Fedora
 * Getting Started With Heat on Ubuntu
 * Heat and Devstack
 * Heat chapter of the OpenStack Clients Guide

Other Links

 * Heat Orchestration Template (HOT) Guide
 * How Heat uses CloudFormation and cloud-init for application deployment
 * Boto Compatibility Matrix
 * VPC Resources Support
 * All topics in the Heat Wiki Namespace
 * Heat Translator Project

heat-core Blogs & Presentation Material

 * Steve Baker Blog
 * Zane Bitter Blog & Presentation Material
 * Steve Dake Blog & Presentation Material
 * Steve Hardy Blog & Presentation Material
 * Angus Salkeld Blog

= Get involved =

IRC
The developers use IRC in  on OFTC for development discussion.

Meetings
Meetings are held on IRC in  on OFTC every Wednesday. See the Heat agenda page for times and details.

Mailing list
Discussions about Heat happens on the openstack-dev mailing list. Please use the tag  in the subject line for new threads.