@startuml
title Upgrade Provider and change contract version
actor User
participant APIServer
participant "Management Cluster\nController" as Controller

note over APIServer
Current State:
A core provider exists with version 
v0.3.10 abiding by contract v1alpha3
end note
====
User -> APIServer: kubectl apply -f updated-provider.yaml

activate APIServer
APIServer --> Controller: upgrade core provider to v0.4.0\nwhich abides by contract v1alpha4
activate Controller
Controller -> Controller: Reconcile

Controller -> APIServer: Get existing Core provider
APIServer --> Controller: Response

note over Controller
- Verify if the Core provider exists
- Get the Status.Contract of existing provider
end note

Controller -> APIServer: Get metadata from ConfigMap for v0.4.0
APIServer --> Controller: Response

note over Controller
Identify that we are upgrading 
the contract of the providers.
end note 

Controller -> APIServer: Get all providers
APIServer --> Controller: Response

note over Controller
For each existing provider,
fetch version that abides by new contract.
If there is a provider that doesn't have a
version that abides by new contract,
then set condition, notify user of error?
Else continue...
end note

Controller -> APIServer: Pause all providers\nto avoid reconciliation

Controller -> APIServer: Delete each provider
Controller -> APIServer: Install new provider

note over Controller
Confirm all health checks,
providers are running.
end note

Controller -> APIServer: Unpause all providers

deactivate APIServer
deactivate Controller
@enduml