Cloud Controller Manager is an alpha feature in 1.8. In upcoming releases it will be the preferred way to integrate Kubernetes with any cloud. This will ensure cloud providers can develop their features independantly from the core Kubernetes release cycles.
Before going into how to build your own cloud controller manager, some background on how it works under the hood is helpful. The cloud controller manager is code from
kube-controller-manager utilizing Go interfaces to allow implementations from any cloud to be plugged in. Most of the scaffolding and generic controller implementations will be in core, but it will always exec out to the cloud interfaces it is provided, so long as the cloud provider interface is satisifed.
To dive a little deeper into implementation details, all cloud controller managers will import packages from Kubernetes core, the only difference being each project will register their own cloud providers by calling cloudprovider.RegisterCloudProvier where a global variable of available cloud providers is updated.
To build an out-of-tree cloud-controller-manager for your cloud, follow these steps:
main.go, ensure your package has an
initblock to run cloudprovider.RegisterCloudProvider.
Using existing out-of-tree cloud providers as an example may be helpful. You can find the list here.