Platform9 Cluster API Integration

Platform9 Cluster API Integration offers you the portability and extensibility of the open-source Cluster API(CAPI) project, with the streamlined and fully-managed experience of Platform9.

With Cluster API, Platform9 brings to you our next-generation Kubernetes Cluster Management, succeeding Platform9's Qbert API based clsuters. It offers clusters based on Cluster API(CAPI), which is extended to integrate transparently into the rest of the Platform9 Stack.

Platform9 Cluster API Concepts

Platform9 SaaS Management Plane

Cluster API requires a Kubernetes cluster known as a Management Cluster that manages the lifecycle of Workload Clusters. It is where one or more Infrastructure Providers run, and resources such as Machines are stored.

Platform9 has integrated the Management Cluster capabilities in the Platform9 SaaS Management Plane so that you don't have to run and manage the life cycle of the management cluster. It also means that all the Cluster API components are always up to date and managed for you.

Workload cluster

A workload cluster is a Kubernetes cluster whose lifecycle is managed by a CAPI Management Cluster.

Infrastructure provider

Infrastructure providers are sources of computational resources, such as compute and networking. For example, cloud Infrastructure Providers include AWS, Azure, and Google, and bare metal Infrastructure Providers include VMware, MAAS, and metal3.io. They run as controllers along with other CAPI services and serve as interfaces between the management cluster and the IaaS Platform.

When there is more than one way to obtain resources from the same Infrastructure Provider (such as AWS offering both EC2 and EKS), each way is referred to as a variant.

Bootstrap provider

The Bootstrap Provider is responsible for:

• Generating the cluster certificates, if not otherwise specified.
• Initialising the control plane, and gating the creation of other nodes until it is complete.
• Joining control plane and worker nodes to the cluster.

Platform9 has developed it own bootstrap provider Nodelet for Native clusters such as on AWS. Whereas managed clusters such as EKS use the bootstrap provider like EKS provided by the Infrastructure Provider

Control plane

Platform9 uses its own provider Nodelet to bootstrap the control plane. As of v1beta1, it exposes the configuration via the NodeletControlPlane object. The controller, nodelet-control-plane-controller-manager, can then create Machine and BootstrapConfig objects based on the requested replicas in the NodeletControlPlane object.

External control planes are offered and controlled by some system other than Cluster API, such as GKE, AKS, EKS, or IKS. Eg: AWSManagedControlPlane for EKS.

Sunpike

Sunpike is a custom Kubernetes API Server running the Platform9 SaaS Management Plane which will store all the CAPI Custom Resources which define your clusters.

Custom Resource Definitions

A CustomResourceDefinition(CRD) is a built-in resource that lets you extend the Kubernetes API. Each CustomResourceDefinition represents a customization of a Kubernetes installation.

CRDs are CAPI specific, Provider Specific(Infrastructure, Bootstrap, Control Plane etc) or PMK specific.

A Group of Custom Resources(CRs - Instances of CRDs) define and construct a CAPI cluster.