kube-vip/pkg/detector/interfaces.go

package detector

import (
	"fmt"
	"net"
)

// This file performs interface detection

// FindIPAddress - this will find the address associated with an adapter
func FindIPAddress(addrName string) (string, string, error) {
	var address string
	list, err := net.Interfaces()
	if err != nil {
		return "", "", err
	}

	for _, iface := range list {
		addrs, err := iface.Addrs()
		if err != nil {
			return "", "", err
		}
		for _, a := range addrs {
			if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
				if ipnet.IP.To16() != nil {
					address = ipnet.IP.String()
					// If we're not searching for a specific adapter return the first one
					if addrName == "" {
						return iface.Name, address, nil
					}
					// If this is the correct adapter return the details
					if iface.Name == addrName {
						return iface.Name, address, nil
					}
				}
			}
		}

	}
	return "", "", fmt.Errorf("unknown interface [%s]", addrName)
}