How do I get the local IP address in Go?
To ensure that you get a non-loopback address, simply check that an IP is not a loopback when you are iterating.
// GetLocalIP returns the non loopback local IP of the host
func GetLocalIP() string {
addrs, err := net.InterfaceAddrs()
if err != nil {
return ""
}
for _, address := range addrs {
// check the address type and if it is not a loopback the display it
if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
if ipnet.IP.To4() != nil {
return ipnet.IP.String()
}
}
}
return ""
}
Here is a better solution to retrieve the preferred outbound ip address when there are multiple ip interfaces exist on the machine.
import (
"log"
"net"
"strings"
)
// Get preferred outbound ip of this machine
func GetOutboundIP() net.IP {
conn, err := net.Dial("udp", "8.8.8.8:80")
if err != nil {
log.Fatal(err)
}
defer conn.Close()
localAddr := conn.LocalAddr().(*net.UDPAddr)
return localAddr.IP
}
You need to loop through all network interfaces
ifaces, err := net.Interfaces()
// handle err
for _, i := range ifaces {
addrs, err := i.Addrs()
// handle err
for _, addr := range addrs {
var ip net.IP
switch v := addr.(type) {
case *net.IPNet:
ip = v.IP
case *net.IPAddr:
ip = v.IP
}
// process IP address
}
}
Play (taken from util/helper.go)