github.com/wfusion/gofusion@v1.1.14/common/utils/ip.go

package utils

import (
	"net"
)

func ClientIP() (ip string) {
	addrs, err := net.InterfaceAddrs()
	if err != nil {
		panic(err)
	}

	for _, address := range addrs {
		if addr, ok := address.(*net.IPNet); ok && !addr.IP.IsLoopback() {
			if addr.IP.To4() != nil {
				return addr.IP.String()
			}

		}
	}

	return
}

func HostIPInDocker() (ip string) {
	addrs, err := net.LookupIP("host.docker.internal")
	if err != nil {
		return
	}

	for _, addr := range addrs {
		if addr.To4() != nil {
			return addr.String()
		}
	}
	return
}

type localIP struct {
	_     func()
	bytes []byte
	str   string
}

func (l *localIP) Bytes() (d []byte) {
	if l.bytes == nil {
		return
	}
	d = make([]byte, len(l.bytes), cap(l.bytes))
	copy(d, l.bytes)
	return
}

func (l *localIP) String() string {
	return l.str
}

var LocalIP = &localIP{
	str: ClientIP(),
	bytes: func() []byte {
		reverse := func(bs []byte) {
			i, j := 0, len(bs)-1
			for i < j {
				bs[i], bs[j] = bs[j], bs[i]
				i++
				j--
			}
		}

		if ipAddr := ClientIP(); ipAddr != "" {
			realIP := []byte("000000000000")
			idx := 0
			for i := len(ipAddr) - 1; i >= 0; i-- {
				c := ipAddr[i]
				if c == '.' {
					idx = (((idx - 1) / 3) + 1) * 3
					continue
				}
				realIP[idx] = c
				idx++
			}
			reverse(realIP)
			return realIP
		}
		return []byte("000000000000")
	}(),
}