Overview

When deployed on OpenStack, OpenShift Container Platform can be configured to access OpenStack infrastructure, including using OpenStack Cinder volumes as persistent storage for application data.

Configuring OpenStack Variables

To set the required OpenStack variables, create a /etc/cloud.conf file with the following contents on all of your OpenShift Container Platform hosts, both masters and nodes:

[Global]
auth-url = <OS_AUTH_URL>
username = <OS_USERNAME>
password = <password>
domain-id = <OS_USER_DOMAIN_ID>
tenant-id = <OS_TENANT_ID>
region = <OS_REGION_NAME>

[LoadBalancer]
subnet-id = <UUID of the load balancer subnet>

Consult your OpenStack administrators for values of the OS_ variables, which are commonly used in OpenStack configuration.

Configuring OpenShift Container Platform Masters for OpenStack

You can set an OpenStack configuration on your OpenShift Container Platform master and node hosts in two different ways:

Configuring OpenShift Container Platform for OpenStack with Ansible

During advanced installations, OpenStack can be configured using the following parameters, which are configurable in the inventory file:

  • openshift_cloudprovider_kind

  • openshift_cloudprovider_openstack_auth_url

  • openshift_cloudprovider_openstack_username

  • openshift_cloudprovider_openstack_password

  • openshift_cloudprovider_openstack_domain_id

  • openshift_cloudprovider_openstack_domain_name

  • openshift_cloudprovider_openstack_tenant_id

  • openshift_cloudprovider_openstack_tenant_name

  • openshift_cloudprovider_openstack_region

  • openshift_cloudprovider_openstack_lb_subnet_id

Example 1. Example OpenStack Configuration with Ansible
# Cloud Provider Configuration
#
# Note: You may make use of environment variables rather than store
# sensitive configuration within the ansible inventory.
# For example:
#openshift_cloudprovider_openstack_username="{{ lookup('env','USERNAME') }}"
#openshift_cloudprovider_openstack_password="{{ lookup('env','PASSWORD') }}"
#
# Openstack
#openshift_cloudprovider_kind=openstack
#openshift_cloudprovider_openstack_auth_url=http://openstack.example.com:35357/v2.0/
#openshift_cloudprovider_openstack_username=username
#openshift_cloudprovider_openstack_password=password
#openshift_cloudprovider_openstack_domain_id=domain_id
#openshift_cloudprovider_openstack_domain_name=domain_name
#openshift_cloudprovider_openstack_tenant_id=tenant_id
#openshift_cloudprovider_openstack_tenant_name=tenant_name
#openshift_cloudprovider_openstack_region=region
#openshift_cloudprovider_openstack_lb_subnet_id=subnet_id

Manually Configuring OpenShift Container Platform Masters for OpenStack

Edit or create the master configuration file on all masters (/etc/origin/master/master-config.yaml by default) and update the contents of the apiServerArguments and controllerArguments sections:

kubernetesMasterConfig:
  ...
  apiServerArguments:
    cloud-provider:
      - "openstack"
    cloud-config:
      - "/etc/cloud.conf"
  controllerArguments:
    cloud-provider:
      - "openstack"
    cloud-config:
      - "/etc/cloud.conf"

When triggering a containerized installation, only the directories of /etc/origin and /var/lib/origin are mounted to the master and node container. Therefore, cloud.conf should be in /etc/origin/ instead of /etc/.

Manually Configuring OpenShift Container Platform Nodes for OpenStack

Edit or create the node configuration file on all nodes (/etc/origin/node/node-config.yaml by default) and update the contents of the kubeletArguments and nodeName sections:

nodeName:
  <instance_name> (1)

kubeletArguments:
  cloud-provider:
    - "openstack"
  cloud-config:
    - "/etc/cloud.conf"
1 Name of the OpenStack instance where the node runs (i.e., name of the virtual machine)

Currently, the nodeName must match the instance name in Openstack in order for the cloud provider integration to work properly. The name must also be RFC1123 compliant.

When triggering a containerized installation, only the directories of /etc/origin and /var/lib/origin are mounted to the master and node container. Therefore, cloud.conf should be in /etc/origin/ instead of /etc/.

Applying Configuration Changes

Start or restart OpenShift Container Platform services on all master and node hosts to apply your configuration changes:

# systemctl restart atomic-openshift-master
# systemctl restart atomic-openshift-node

Switching from not using a cloud provider to using a cloud provider produces an error message. Adding the cloud provider tries to delete the node because the node switches from using the hostname as the externalID (which would have been the case when no cloud provider was being used) to using the OpenStack instance-id (which is what the OpenStack cloud provider specifies). To resolve this issue:

  1. Log in to the CLI as a cluster administrator.

  2. Check and backup existing node labels:

    $ oc describe node <node_name> | grep -Poz '(?s)Labels.*\n.*(?=Taints)'
  3. Delete the nodes:

    $ oc delete node <node_name>
  4. On each node host, restart the OpenShift Container Platform service.

    $ systemctl restart atomic-openshift-node
  5. Add back any labels on each node that you previously had.