Configuring Multiple OpenStack Regions

Overview

Platform9 Managed OpenStack enables administrators to manage multiple regions as part of their OpenStack cloud infrastructure. Datacenter resources in separate regions are managed by distinct sets of OpenStack management services (Nova/Glance/Cinder, etc.) but share a single Keystone identity server, and thus a single set of user, tenant and role settings.

An administrator might choose to add additional regions

In version 1.5, users will notice a new menu at the top of the Platform9 user interface that allows them to select from a list of regions. Choosing a particular region gives them control over the resources managed by that region's services.

regions

Note that hosts, images, instances, networks and cinder volumes are all secluded within the region. Resources from a particular region are only available when that region is selected.

Regions and the Keystone Service Catalog

When using the OpenStack command line clients, it's important to understand how regions help the clients (WebUI or command-line) locate the various services. The Keystone identity service assists with connection to cloud management services by maintaining a catalog of the endpoints for each of the other services. Each endpoint listed in the Keystone service catalog contains:

Given the Keystone service catalog, a client can find a URL for the service and region he wishes to use.

In general, a client wishing to send a request to one of the management services follows this sequence:

For multi-region clouds, when using the OpenStack command line clients, it will be necessary to include the region name in the command line. For example, to get a list of instances in region 'williamsport-pa', the Nova client must be invoked as follows:

nova --os-region williamport-pa list

This tells Nova to list the instances managed by the nova-api service in the williamsport-pa region. Other OpenStack commmand line clients have a similar command line setting to select the region for the call.


February 02, 2016