Blueprint-api-feature-discovery


 * Launchpad Entry: NovaSpec:api-feature-discovery
 * Created:
 * Contributors:

Summary
Allow third-party or implementation-specific features to be discovered.

Release Note
Added support for discovery of API features. In addition to /versions for API versions, you can now visit /features (authentication required) to see what optional components are enabled, or what third-party features have been installed.

Rationale
Cloud providers will want to differentiate themselves and add new features into their deployments. This provides a way for them to work with standard OpenStack API tools, as well as clients that are aware of the vendor-specific extensions that are installed. Examples could be annotating reservations with deployment information on how to run e.g. Puppet, Chef, or cfengine.

Design
Add an authenticated endpoint (/features) that returns a properly formatted (json, xml, yaml, or other supported encoding) dictionary of {  plugin0 => [VERSION0, VERSION1, ...], plugin1 => [VERSION0, VERSION1]  }

Each optional / additional plugin should be accessed via (/features/plugin-name/version-number[/.*]).

This requires a smart loading mechanism for plugins, as well as a way to modify the router.