const (
	StateFileLock     = "lock"
	StateFileChildPID = "child_pid" // decimal pid number text
	StateFileAPISock  = "api.sock"  // REST API Socket
)

type Opt struct {
	PipeFDEnvKey   string               // needs to be set
	StateDir       string               // directory needs to be precreated
	StateDirEnvKey string               // optional env key to propagate StateDir value
	NetworkDriver  network.ParentDriver // nil for HostNetwork
	PortDriver     port.ParentDriver    // nil for --port-driver=none
}