/
net.go
72 lines (65 loc) · 1.32 KB
/
net.go
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package utils
import (
"errors"
"fmt"
"net"
)
var (
externalIP string
)
// nolint:gochecknoinits
func init() {
var err error
if externalIP, err = getExternalIP(); err != nil {
panic(fmt.Errorf("get external ip, reason=%v", err))
}
}
// GetExternalIP return the first available external ip address
func GetExternalIP() string {
return externalIP
}
func getExternalIP() (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 "", errors.New("not connected to the network")
}
// IsErrClosing return true if err indicates socket is closing
func IsErrClosing(err error) bool {
var opErr *net.OpError
if errors.As(err, &opErr) {
err = opErr.Err
}
// nolint:stylecheck
return "use of closed network connection" == err.Error()
}