// docker-proxy provides a network Proxy interface and implementations for TCP
// and UDP.
package main

// ipVersion refers to IP version - v4 or v6
type ipVersion string

const (
	// IPv4 is version 4
	ip4 ipVersion = "4"
	// IPv4 is version 6
	ip6 ipVersion = "6"
)

// Proxy defines the behavior of a proxy. It forwards traffic back and forth
// between two endpoints : the frontend and the backend.
// It can be used to do software port-mapping between two addresses.
// e.g. forward all traffic between the frontend (host) 127.0.0.1:3000
// to the backend (container) at 172.17.42.108:4000.
type Proxy interface {
	// Run starts forwarding traffic back and forth between the front
	// and back-end addresses.
	Run()
	// Close stops forwarding traffic and close both ends of the Proxy.
	Close()
}