Find IP address that matches a subset.

main.go

package main

import (
	"bytes"
	"fmt"
	"log"
	"net"
)

func main() {
	ifaces, err := net.Interfaces()
	if err != nil {
		log.Print(fmt.Errorf("localAddresses: %v\n", err.Error()))
		return
	}
	for _, i := range ifaces {
		addrs, err := i.Addrs()
		if err != nil {
			log.Print(fmt.Errorf("localAddresses: %v\n", err.Error()))
			continue
		}
		for _, a := range addrs {
			switch v := a.(type) {
			case *net.IPNet:
				needle := []byte(`10.7.7.`)
				hay := []byte(v.IP.String())
				if bytes.Contains(hay, needle) {
					log.Println("YES")
				}
			}

		}
	}
}