// PodLifecycleHandler defines the interface used by the PodController to react
// to new and changed pods scheduled to the node that is being managed.
//
// Errors produced by these methods should implement an interface from
// github.com/virtual-kubelet/virtual-kubelet/errdefs package in order for the
// core logic to be able to understand the type of failure.
type PodLifecycleHandler interface {
    // CreatePod takes a Kubernetes Pod and deploys it within the provider.
    CreatePod(ctx context.Context, pod *corev1.Pod) error

    // UpdatePod takes a Kubernetes Pod and updates it within the provider.
    UpdatePod(ctx context.Context, pod *corev1.Pod) error

    // DeletePod takes a Kubernetes Pod and deletes it from the provider.
    DeletePod(ctx context.Context, pod *corev1.Pod) error

    // GetPod retrieves a pod by name from the provider (can be cached).
    // The Pod returned is expected to be immutable, and may be accessed
    // concurrently outside of the calling goroutine. Therefore it is recommended
    // to return a version after DeepCopy.
    GetPod(ctx context.Context, namespace, name string) (*corev1.Pod, error)

    // GetPodStatus retrieves the status of a pod by name from the provider.
    // The PodStatus returned is expected to be immutable, and may be accessed
    // concurrently outside of the calling goroutine. Therefore it is recommended
    // to return a version after DeepCopy.
    GetPodStatus(ctx context.Context, namespace, name string) (*corev1.PodStatus, error)

    // GetPods retrieves a list of all pods running on the provider (can be cached).
    // The Pods returned are expected to be immutable, and may be accessed
    // concurrently outside of the calling goroutine. Therefore it is recommended
    // to return a version after DeepCopy.
    GetPods(context.Context) ([]*corev1.Pod, error)
}

type PodMetricsProvider interface {
    GetStatsSummary(context.Context) (*stats.Summary, error)
}