The Gardener implements the automated management and operation of Kubernetes clusters as a service and aims to support that service on multiple Cloud providers (AWS, GCP, Azure, OpenStack). Its main principle is to use Kubernetes itself as base for its tasks.
In essence, the Gardener is an extension API server along with a bundle of Kubernetes controllers which introduces new API objects in an existing Kubernetes cluster (which is called Garden cluster) in order to use them for the management of further Kubernetes clusters (which are called Shoot clusters). To do that reliably and to offer a certain quality of service, it requires to control the main components of a Kubernetes cluster (etcd, API server, controller manager, scheduler). These so-called control plane components are hosted in Kubernetes clusters themselves (which are called Seed clusters).
Please find more information regarding the concepts and a detailed description of the architecture in our Kubernetes Wiki.
See our documentation in the /docs repository, please find the index here.
Feedback is always welcome. Please report bugs or suggestions about our Kubernetes clusters as such or the Gardener itself as GitHub issues.