netmaker/logic/network.go

package logic

import (
	"net"

	"github.com/gravitl/netmaker/models"
)

// GetLocalIP - gets the local ip
func GetLocalIP(node models.Node) string {

	var local string

	ifaces, err := net.Interfaces()
	if err != nil {
		return local
	}
	_, localrange, err := net.ParseCIDR(node.LocalRange)
	if err != nil {
		return local
	}

	found := false
	for _, i := range ifaces {
		if i.Flags&net.FlagUp == 0 {
			continue // interface down
		}
		if i.Flags&net.FlagLoopback != 0 {
			continue // loopback interface
		}
		addrs, err := i.Addrs()
		if err != nil {
			return local
		}
		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				if !found {
					ip = v.IP
					local = ip.String()
					if node.IsLocal == "yes" {
						found = localrange.Contains(ip)
					} else {
						found = true
					}
				}
			case *net.IPAddr:
				if !found {
					ip = v.IP
					local = ip.String()
					if node.IsLocal == "yes" {
						found = localrange.Contains(ip)

					} else {
						found = true
					}
				}
			}
		}
	}
	return local
}