Cloned from launchpad blueprint https://blueprints.launchpad.net/ceilometer/+spec/billing-in-ceilometer. Description: This blueprint aims for providing the admin user of a private cloud facility to view usage and billing details for the spawned instances. Admin can view project-wise billing details of each instance of that project. Usage of resources by the instances will be measured in terms of disk usage, network usage and CPU usage. Total cost for each project will be calculated. Admin user can create rate plans. Rate plans will define charges based on usage by the instance. Any rate plans can be applied for any instance to calculate its billing cost. There will be a default rate plan that will be applied to an instance if admin does not specify explicity which rate plan has to be used. For getting the billing deatils for each tenant/instance we will add more Ceilometer API. Ceilometer will measure usage of resources in terms of disk usage, network usage and CPU usage. Specification URL (additional information): https://wiki.openstack.org/wiki/Ceilometer/blueprints/Add_Billing_in_Ceilometer