prysm-pulse/shared/iputils/external_ip.go
Preston Van Loon 4767b1dfbf Return loopback address when disconnected from network (#1969)
* Return loopback address when disconnected from network

* Update discovery_norace_test.go
2019-03-11 20:01:46 -07:00

47 lines
812 B
Go

package iputils
import (
"fmt"
"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
}
fmt.Print(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
}