@startuml K3s Infrastructure Class Diagram
skinparam classAttributeIconSize 0

title K3s Kubernetes Cluster - Terraform Resource Relationships

package "Terraform Infrastructure" {
  class "Development Environment" as dev {
    + server_ip: string
    + worker_ips: list(string)
    + ssh_user: string
    + ssh_private_key: string
    + replace_url: string
    + domain: string
    + ssl_cert_path: string
    + ssl_key_path: string
    + install_argocd: bool
    + enable_traefik_dashboard: bool
    + enable_ssh_tunnel: bool
  }

  class "K3s Install Module" as k3s_module {
    + server_ip: string
    + worker_ips: list(string)
    + ssh_user: string
    + ssh_private_key: string
    + replace_url: string
    + apply()
    + destroy()
  }
  
  class "null_resource.setup_ssh_config" as ssh_config {
    + triggers: map
    - local-exec: create SSH config
  }
  
  class "null_resource.install_k3s_server" as server_install {
    + depends_on: [setup_ssh_config]
    + triggers: map
    - remote-exec: install K3s server
    - remote-exec: uninstall on destroy
  }
  
  class "null_resource.get_k3s_config" as get_config {
    + depends_on: [install_k3s_server, setup_ssh_config]
    - remote-exec: copy kubeconfig
    - local-exec: download kubeconfig
    - local-exec: update server URL
  }
  
  class "null_resource.get_k3s_token" as get_token {
    + depends_on: [install_k3s_server, setup_ssh_config]
    - remote-exec: extract node token
    - local-exec: download token
  }
  
  class "null_resource.copy_token_to_workers" as copy_token {
    + depends_on: [get_k3s_token]
    + count: length(worker_ips)
    - file: upload token to worker
  }
  
  class "null_resource.install_k3s_worker" as worker_install {
    + depends_on: [copy_token_to_workers]
    + count: length(worker_ips)
    + triggers: map
    - remote-exec: install K3s agent
    - remote-exec: uninstall on destroy
  }
  
  class "Output" as output {
    + kubeconfig_path: string
  }
}

package "External Resources" {
  class "Server Node" as server {
    + hostname: string
    + K3s server
    + Control plane components
    + Node token
    + Kubeconfig
  }
  
  class "Worker Node" as worker {
    + hostname: string
    + K3s agent
    + Container runtime
  }
}

dev --> k3s_module : uses
k3s_module --> ssh_config : creates
k3s_module --> server_install : creates
k3s_module --> get_config : creates
k3s_module --> get_token : creates
k3s_module --> copy_token : creates
k3s_module --> worker_install : creates
k3s_module --> output : provides

ssh_config ..> server : configures access
ssh_config ..> worker : configures access
server_install ..> server : provisions
get_config ..> server : extracts config
get_token ..> server : extracts token
copy_token ..> worker : transfers token
worker_install ..> worker : provisions

note bottom of k3s_module
  The K3s Install Module orchestrates the provisioning of a K3s Kubernetes cluster 
  by creating and managing the necessary resources in sequence:
  1. Set up SSH configuration
  2. Install K3s on server node
  3. Retrieve kubeconfig and node token
  4. Copy token to worker nodes
  5. Install K3s agents on worker nodes
end note

footer K3s Infrastructure Class Diagram - Version 1.0
@enduml