In the generic cluster architecture, our cluster needs a local configuration management tool like confd to pull updates from the Discovery Service and Global Configuration Stores. This ensures applications running on the node are using the most up-to-date parameters.
In Kubernetes, this is the job of kubelet. However, kubelet does a lot more than just updating the local configuration and restarting services. It also monitors each service, make sure they are running and healthy, and reports their status back to etcd via kube-apiserver.
