Welcome to Nova’s developer documentation!

Nova is an OpenStack project designed to provide power massively scalable, on demand, self service access to compute resources.

The developer documentation provided here is continually kept up-to-date based on the latest code, and may not represent the state of the project at any specific prior release.


This is documentation for developers, if you are looking for more general documentation including API, install, operator and user guides see docs.openstack.org

This documentation is intended to help explain what the Nova developers think is the current scope of the Nova project, as well as the architectural decisions we have made in order to support that scope. We also document our plans for evolving our architecture over time. Finally, we documented our current development process and policies.

Compute API References

Nova has had a v2 API for a long time. We are currently in the process of moving to a new implementation of that API, which we have called v2.1. v2.1 started life as an API called v3, but that name should never be used any more. We are currently in the process of transitioning users over to the v2.1 implementation, at which point the v2 code will be deleted.

Changes to the Compute API post v2.1 are made using microversions. You can see a history of our microversions here:

We also have a local copy of the v2 docs:

There was a session on the v2.1 API at the Liberty summit which you can watch here.

Hypervisor Support Matrix

The hypervisor support matrix is how we document what features we require hypervisor drivers to implement, as well as the level of support for optional features that we currently have. You can see the support matrix here:

Developer Guide

If you are new to Nova, this should help you start to understand what Nova actually does, and why.

Development Policies

The Nova community is a large community. We have lots of users, and they all have a lot of expectations around upgrade and backwards compatibility. For example, having a good stable API, with discoverable versions and capabilities is important for maintaining the strong ecosystem around Nova.

Our process is always evolving, just as Nova and the community around Nova evolves over time. If there are things that seem strange, or you have ideas on how to improve things, please engage in that debate, so we continue to improve how the Nova community operates.

This section looks at the processes and why. The main aim behind all the process is to aid good communication between all members of the Nova community, while keeping users happy and keeping developers productive.

Architecture Concepts

This follows on for the discussion in the introduction, and digs into details on specific parts of the Nova architecture.

We find it important to document the reasons behind our architectural decisions, so its easier for people to engage in the debates about the future of Nova’s architecture. This is all part of Open Design and Open Development.

Architecture Evolution Plans

The following section includes documents that describe the overall plan behind groups of nova-specs. Most of these cover items relating to the evolution of various parts of Nova’s architecture. Once the work is complete, these documents will move into the “Concepts” section. If you want to get involved in shaping the future of Nova’s architecture, these are a great place to start reading up on the current plans.

Indices and tables