Nova service plugin

This spec is proposed to support nova service plugin (OS::Nova::Service, note that OS::Nova::Service doesn’t exist in heat resource type same as the hypervisor plugin, and it is an admin-only resource type), and versioned notifications are supported for services in nova [0], it would be a nice additional plugin for Searchlight.

Problem Description

A service[1] takes a manager and enables rpc by listening to queues based on topic. It also periodically runs tasks on the manager and reports its state to the database services table. So in cloud with large amount of compute nodes, there will be a pretty large number of services (typically one service each compute node, and four services each controller node). The list or search services (you can use command nova service-list to get the whole list or filter the result by host or binary) may get slow using the native nova API. And the versioned notifications for hypervisor [2] refers to the service id. In future implementation for notification in hypervisor plugin [3] we may want to fetch the service details for hypervisor create or update action by the service id.

Proposed Change

  1. Support index services through nova API.

  2. Support versioned notifications.