design.puml

@startuml
title Ephemeral Namespace Management
!include <C4/C4_Component>

Person(user, "App Developer")
Component(reso, "NamespaceReservation", "k8s custom resource", "Acts as interface for the lifecycle of an ephemeral namespace")
Component(controller, "NamespaceReservation controller", "k8s controller", "Manages ephemeral namespaces.  Specifically, it creates ephemeral namespaces and populates them with common resources.")
Component(pool, "Namespace pool", "k8s namespaces", "Pool of pre-populated namespaces ready to be reserved")
Component(ns, "Checked out namesapce", "k8s namespace", "Namespace checked out to user.  Will be deleted at end of reservation")

Rel(user, reso, "User creates reservation, and reads it to know which namespace to use")
Rel(reso, controller, "Controller reads reservation to check out namespace and to know when to delete")
Rel_R(pool, controller, "Controller keeps pool of 'on-deck' namespaces to speed up ephemeral environment initialization")
Rel(controller, ns, "Checks out by setting name on status of reservation and adding RoleBindings")
Rel(user, ns, "Interacts directly with namespace once checked out")

@enduml