Multiple Regions Deployment with Kolla

This section describes how to perform a basic multiple region deployment with Kolla. A basic multiple region deployment consists of separate OpenStack installations 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 internal endpoint (for example, 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 is specifications of multiple regions deployment at 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 whether it is an all-in-one or multinode deployment (see Quick Start). 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 known as RegionOne, that is hidden 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_internal_url: "{{ internal_protocol }}://{{ kolla_internal_fqdn_r1 }}:{{ keystone_public_port }}"

openstack_auth:
    auth_url: "{{ keystone_internal_url }}"
    username: "{{ keystone_admin_user }}"
    password: "{{ keystone_admin_password }}"
    user_domain_name: "{{ default_user_domain_name }}"
    system_scope: "all"

Note

If the kolla_internal_vip_address and/or the kolla_external_vip_address reside on the same subnet as kolla_internal_fqdn_r1, you should set the keepalived_virtual_router_id value in the /etc/kolla/globals.yml to a unique number.

Configuration files of cinder,nova,neutron,glance… have to be updated to contact RegionOne’s Keystone. Fortunately, Kolla allows you to override all configuration files at the same time thanks to the node_custom_config variable (see OpenStack Service Configuration in Kolla). To do so, create a global.conf file with the following content:

[keystone_authtoken]
www_authenticate_uri = {{ keystone_internal_url }}
auth_url = {{ keystone_internal_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_internal_url }}

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

[trustee]
www_authenticate_uri = {{ keystone_internal_url }}
auth_url = {{ keystone_internal_url }}

[ec2authtoken]
www_authenticate_uri = {{ keystone_internal_url }}

[clients_keystone]
www_authenticate_uri = {{ keystone_internal_url }}

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

[service_credentials]
auth_url = {{ keystone_internal_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.