prysm-pulse/shared/iputils/external_ip.go

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2018-08-14 16:16:21 +00:00
package iputils
import (
"net"
)
// ExternalIPv4 returns the first IPv4 available.
func ExternalIPv4() (string, error) {
ifaces, err := net.Interfaces()
if err != nil {
return "", err
}
for _, iface := range ifaces {
if iface.Flags&net.FlagUp == 0 {
continue // interface down
}
if iface.Flags&net.FlagLoopback != 0 {
continue // loopback interface
}
addrs, err := iface.Addrs()
if err != nil {
return "", 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
}
if ip == nil || ip.IsLoopback() {
continue
}
ip = ip.To4()
if ip == nil {
continue // not an ipv4 address
}
return ip.String(), nil
}
}
return "127.0.0.1", nil
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}