7장. OpenStack Cloud Controller Manager reference guide

Beginning with OpenShift Container Platform 4.12, clusters that run on Red Hat OpenStack Platform (RHOSP) were switched from the legacy OpenStack cloud provider to the external OpenStack Cloud Controller Manager (CCM). This change follows the move in Kubernetes from in-tree, legacy cloud providers to external cloud providers that are implemented by using the Cloud Controller Manager.

To preserve user-defined configurations for the legacy cloud provider, existing configurations are mapped to new ones as part of the migration process. It searches for a configuration called cloud-provider-config in the openshift-config namespace.

Found configurations are synchronized to the cloud-conf config map in the openshift-cloud-controller-manager namespace.

As part of this synchronization, the OpenStack CCM Operator alters the new config map such that its properties are compatible with the external cloud provider. The file is changed in the following ways:

Additionally, the CCM Operator enforces a number of default options. Values for these options are always overriden as follows:

[Global]
use-clouds = true
clouds-file = /etc/openstack/secret/clouds.yaml
cloud = openstack
...

[LoadBalancer]
enabled = true

The clouds-value value, /etc/openstack/secret/clouds.yaml, is mapped to the openstack-cloud-credentials config in the openshift-cloud-controller-manager namespace. You can modify the RHOSP cloud in this file as you do any other clouds.yaml file.