Terminology

Web Portal (Portal)

This is the aggregated view and entry point for the user. It provides the mechanisms for the multi-tenant, multi-service-provider self-service portal.

Control Plane (CP)

This runs Crossplane and the AppCat Control Plane (Kubernetes API) which manages all the service instances on worker clusters. Each zone of a Service Provider runs at least one CP.

Worker Cluster

Clusters running the actual workload, managed by the Control Plane. Each zone of a CSP runs at least one Worker Cluster. Services are directly exposed to the end-user.

Service

A generic service like "PostgreSQL" or "Keycloak". This doesn’t include pricing or any other aspect of a managed service.

Plan

A bundle of a service, a price, an SLA and other parameters to form an offering. It can be instantiated (ordered) and parametrized according to the specification in the offering.

Crossplane specific terms

  • Compositions - A template to define how to create resources.

  • Composite Resource Definition (XRD) - A custom API specification.

  • Composite Resource (XR) - Created by using the custom API defined in a Composite Resource Definition. XRs use the Composition template to create new managed resources.

  • Claims (XRC) - Like a Composite Resource, but with namespace scoping.

  • Managed Resource (MR) - Represents an external service in a Provider.

  • Providers enable Crossplane to provision infrastructure on an external service. Providers create new Kubernetes APIs and map them to external APIs.