The EWC Kubernetes Service is a core part of the European Weather Cloud (EWC), providing a centralized platform for managing Kubernetes clusters.
The service managed at ECMWF side of EWC is based on Magnum, which is an OpenStack API service which makes container orchestration engines (COE) such as Kubernetes available as first class resources in OpenStack.
Magnum offers complete life-cycle management of Kubernetes in an OpenStack environment, integrated with other OpenStack services for a seamless experience for OpenStack users who wish to run containers in an OpenStack environment.
This section introduces the fundamental concepts and components that are part of the system.
ClusterTemplate
A ClusterTemplate is a collection of parameters to describe how a cluster can be constructed. This includes the definition of both control plane and worker nodes.
ECMWF manages a pre-defined collections of cluster templates that are ready to use for instantiating new Kubernetes cluster.
Cluster
A cluster is an instance of the ClusterTemplate of a Kubernetes container orchestration engines (COE). Magnum deploys a cluster by referring to the attributes defined in the particular ClusterTemplate as well as a few additional parameters for the cluster. Magnum deploys the orchestration templates provided by the cluster driver to create and configure all the necessary infrastructure. When ready, the cluster is an operational Kubernetes that can host containers.
The cluster, including both control plane and worker nodes, once deployed resides on the Openstack cloud project belonging to the EWC user tenancy.
LifeCycle
A set of life cycle operations on the cluster is one of the capabilities that Magnum provides, enabling clusters to be managed on OpenStack.
The user can interact with the Magnum service to create, manage and delete his own deployed clusters.
Magnum Python Command-line Client
The Magnum python command-line client "python-magnumclient" allows to interact with the Magnum Openstack API service and to manage the Kubernetes cluster life cycle.