@startuml
title User scales up a KubeadmControlPlane
actor User

' -- GROUPS START ---

box #lightgreen
participant "API Server"
end box

box #violet
participant "KubeadmControlPlane Controller"
end box

' -- GROUPS END ---

User->"API Server":kubectl scale cp/my-control-plane -replicas=3
"API Server"-->>"KubeadmControlPlane Controller": KubeadmControlPlane Updated

"KubeadmControlPlane Controller"-> "KubeadmControlPlane Controller":Enqueues KubeadmControlPlane Reconcile

"KubeadmControlPlane Controller"-> "KubeadmControlPlane Controller":KubeadmControlPlane Controller Reconcile
activate "KubeadmControlPlane Controller"

note over "KubeadmControlPlane Controller": - ✅ KubeadmControlPlane.OwnerReferences \ncontains a Cluster

"KubeadmControlPlane Controller"->"API Server": Get Cluster
"KubeadmControlPlane Controller"<<--"API Server": Response

note over "KubeadmControlPlane Controller": - ✅ Cluster.Status.InfrastructureReady is true\n- ✅ KubeadmControlPlane instance is valid

"KubeadmControlPlane Controller"->"API Server": Get Machines matching label selector
"KubeadmControlPlane Controller"<<--"API Server": Response

opt #FFFFFFCC KubeadmControlPlane.Spec.Replicas >= 1, all existing Machines "Ready", num Machines < Replicas

"KubeadmControlPlane Controller"->"API Server": Create KubeadmConfig from KubeadmControlPlane.Spec.KubeadmConfigSpec
"KubeadmControlPlane Controller"<<--"API Server": Response

"KubeadmControlPlane Controller"->"API Server": Create InfrastructureMachine from KubeadmControlPlane.Spec.InfrastructureTemplate
"KubeadmControlPlane Controller"<<--"API Server": Response

"KubeadmControlPlane Controller"->"API Server": Create Machine using refs from created KubeadmConfig and InfrastructureMachine resources
"KubeadmControlPlane Controller"<<--"API Server": Response

end

"KubeadmControlPlane Controller"->"API Server": Update KubeadmControlPlane
"KubeadmControlPlane Controller"<<--"API Server": Response

hide footbox
@enduml