multi-regions.rst

Multiple Regions Deployment with Kolla

This section describes how to perform a basic multiple regions deployment with Kolla. A basic multiple regions deployment consists of separate OpenStack installation in two or more regions (RegionOne, RegionTwo, ...) with a shared Keystone and Horizon. The rest of this documentation assumes Keystone and Horizon are deployed in RegionOne, and other regions have access to the admin endpoint (i.e., kolla_internal_fqdn) of RegionOne. It also assumes that the operator knows the name of all OpenStack regions in advance, and considers as many Kolla deployments as there are regions.

There are specifications of multiple regions deployment at: http://docs.openstack.org/arch-design/multi-site-architecture.html and https://wiki.openstack.org/wiki/Heat/Blueprints/Multi_Region_Support_for_Heat.

Deployment of the first region with Keystone and Horizon

Deployment of the first region results in a typical Kolla deployment whenever, it is an all-in-one or multinode deployment (see :doc:`quickstart`). It only requires slight modifications in the /etc/kolla/globals.yml configuration file. First of all, ensure that Keystone and Horizon are enabled:

enable_keystone: "yes"
enable_horizon: "yes"

Then, change the value of multiple_regions_names to add names of other regions. In this example, we consider two regions. The current one, formerly knows as RegionOne, that is hided behind openstack_region_name variable, and the RegionTwo:

openstack_region_name: "RegionOne"
multiple_regions_names:
    - "{{ openstack_region_name }}"
    - "RegionTwo"

Note

Kolla uses these variables to create necessary endpoints into Keystone so that services of other regions can access it. Kolla also updates the Horizon local_settings to support multiple regions.

Finally, note the value of kolla_internal_fqdn and run kolla-ansible. The kolla_internal_fqdn value will be used by other regions to contact Keystone. For the sake of this example, we assume the value of kolla_internal_fqdn is 10.10.10.254.

Deployment of other regions

Deployment of other regions follows an usual Kolla deployment except that OpenStack services connect to the RegionOne's Keystone. This implies to update the /etc/kolla/globals.yml configuration file to tell Kolla how to reach Keystone. In the following, kolla_internal_fqdn_r1 refers to the value of kolla_internal_fqdn in RegionOne:

kolla_internal_fqdn_r1: 10.10.10.254

keystone_admin_url: "{{ admin_protocol }}://{{ kolla_internal_fqdn_r1 }}:{{ keystone_admin_port }}/v3"
keystone_internal_url: "{{ internal_protocol }}://{{ kolla_internal_fqdn_r1 }}:{{ keystone_public_port }}/v3"

openstack_auth:
    auth_url: "{{ admin_protocol }}://{{ kolla_internal_fqdn_r1 }}:{{ keystone_admin_port }}"
    username: "admin"
    password: "{{ keystone_admin_password }}"
    project_name: "admin"

Configuration files of nova/neutron/glance... have to be updated to contact RegionOne's Keystone. Fortunately, Kolla offers to override all configuration files at the same time thanks to the node_custom_config variable (see :ref:`service-config`). This implies to create a global.conf file with the following content:

[keystone_authtoken]
auth_uri = {{ keystone_internal_url }}
auth_url = {{ keystone_admin_url }}

The Placement API section inside the nova configuration file also has to be updated to contact RegionOne's Keystone. So create, in the same directory, a nova.conf file with below content:

[placement]
auth_url = {{ keystone_admin_url }}

And link the directory that contains these files into the /etc/kolla/globals.yml:

node_custom_config: path/to/the/directory/of/global&nova_conf/

Also, change the name of the current region. For instance, RegionTwo:

openstack_region_name: "RegionTwo"

Finally, disable the deployment of Keystone and Horizon that are unnecessary in this region and run kolla-ansible:

enable_keystone: "no"
enable_horizon: "no"

The configuration is the same for any other region.