OpenStack Cloud Controller Manager - An external cloud controller manager for running kubernetes in an OpenStack cluster.
External cloud providers were introduced as an Alpha feature in Kubernetes release 1.6. openstack-cloud-controller-manager
is the implementation of external cloud provider for OpenStack clusters. An external cloud provider
is a kubernetes controller that runs cloud provider-specific loops required for the functioning of
kubernetes. These loops were originally a part of the kube-controller-manager, but they were tightly
coupling the kube-controller-manager to cloud-provider specific code. In order to free the kubernetes
project of this dependency, the cloud-controller-manager was introduced.
cloud-controller-manager allows cloud vendors and kubernetes core to evolve independent of each other.
In prior releases, the core Kubernetes code was dependent upon cloud provider-specific code for functionality.
In future releases, code specific to cloud vendors should be maintained by the cloud vendor themselves, and
linked to cloud-controller-manager while running Kubernetes.
As such, you must disable these controller loops in the kube-controller-manager if you are running the
openstack-cloud-controller-manager. You can disable the controller loops by setting the --cloud-provider
flag to external when starting the kube-controller-manager.
For more details, please see:
- https://github.com/kubernetes/enhancements/blob/master/keps/sig-cloud-provider/20180530-cloud-controller-manager.md
- https://kubernetes.io/docs/tasks/administer-cluster/running-cloud-controller/#running-cloud-controller-manager
- https://kubernetes.io/docs/tasks/administer-cluster/developing-cloud-controller-manager/
Here are some examples of how you could leverage openstack-cloud-controller-manager: