apiVersion: "autoscaling.agones.dev/v1"
kind: FleetAutoscaler
# FleetAutoscaler Metadata
# https://v1-24.docs.kubernetes.io/docs/reference/generated/kubernetes-api/v1.24/#objectmeta-v1-meta
metadata:
  name: fleet-autoscaler-example
spec:
  # The name of the fleet to attach to and control. Must be an existing Fleet in the same namespace
  # as this FleetAutoscaler
  fleetName: fleet-example
  # The autoscaling policy
  policy:
    # type of the policy. for now, only Buffer is available
    type: Buffer
    # parameters of the buffer policy
    buffer:
      # Size of a buffer of "ready" game server instances
      # The FleetAutoscaler will scale the fleet up and down trying to maintain this buffer, 
      # as instances are being allocated or terminated
      # it can be specified either in absolute (i.e. 5) or percentage format (i.e. 5%)
      bufferSize: 5
      # minimum fleet size to be set by this FleetAutoscaler. 
      # if not specified, the actual minimum fleet size will be bufferSize
      minReplicas: 10
      # maximum fleet size that can be set by this FleetAutoscaler
      # required
      maxReplicas: 20
  # [Stage:Beta]
  # [FeatureFlag:CustomFasSyncInterval]
  # The autoscaling sync strategy
  sync:
    # type of the sync. for now, only FixedInterval is available
    type: FixedInterval
    # parameters of the fixedInterval sync
    fixedInterval:
      # the time in seconds between each auto scaling
      seconds: 30

apiVersion: "autoscaling.agones.dev/v1"
kind: FleetAutoscaler
metadata:
  name: webhook-fleet-autoscaler
spec:
  fleetName: simple-game-server
  policy:
    # type of the policy - this example is Webhook
    type: Webhook
    # parameters for the webhook policy - this is a WebhookClientConfig, as per other K8s webhooks
    webhook:
      # use a service, or URL
      service:
        name: autoscaler-webhook-service
        namespace: default
        path: scale
      # optional for URL defined webhooks
      # url: ""
      # caBundle:  optional, used for HTTPS webhook type
  # The autoscaling sync strategy
  sync:
    # type of the sync. for now, only FixedInterval is available
    type: FixedInterval
    # parameters of the fixedInterval sync
    fixedInterval:
      # the time in seconds between each auto scaling
      seconds: 30

// FleetAutoscaleReview is passed to the webhook with a populated Request value,
// and then returned with a populated Response.
type FleetAutoscaleReview struct {
	Request  *FleetAutoscaleRequest  `json:"request"`
	Response *FleetAutoscaleResponse `json:"response"`
}

type FleetAutoscaleRequest struct {
	// UID is an identifier for the individual request/response. It allows us to distinguish instances of requests which are
	// otherwise identical (parallel requests, requests when earlier requests did not modify etc)
	// The UID is meant to track the round trip (request/response) between the Autoscaler and the WebHook, not the user request.
	// It is suitable for correlating log entries between the webhook and apiserver, for either auditing or debugging.
	UID types.UID `json:"uid""`
	// Name is the name of the Fleet being scaled
	Name string `json:"name"`
	// Namespace is the namespace associated with the request (if any).
	Namespace string `json:"namespace"`
	// The Fleet's status values
	Status v1.FleetStatus `json:"status"`
}

type FleetAutoscaleResponse struct {
	// UID is an identifier for the individual request/response.
	// This should be copied over from the corresponding FleetAutoscaleRequest.
	UID types.UID `json:"uid"`
	// Set to false if no scaling should occur to the Fleet
	Scale bool `json:"scale"`
	// The targeted replica count
	Replicas int32 `json:"replicas"`
}

// FleetStatus is the status of a Fleet
type FleetStatus struct {
	// Replicas the total number of current GameServer replicas
	Replicas int32 `json:"replicas"`
	// ReadyReplicas are the number of Ready GameServer replicas
	ReadyReplicas int32 `json:"readyReplicas"`
	// ReservedReplicas are the total number of Reserved GameServer replicas in this fleet.
	// Reserved instances won't be deleted on scale down, but won't cause an autoscaler to scale up.
	ReservedReplicas int32 `json:"reservedReplicas"`
	// AllocatedReplicas are the number of Allocated GameServer replicas
	AllocatedReplicas int32 `json:"allocatedReplicas"`
}