package main

import (
        "fmt"
        "github.com/vishvananda/netns"
        "io/ioutil"
        "log"
        "net"
        "runtime"
        "sync"
)

func readInterfaces(wg *sync.WaitGroup) {
        fmt.Printf("Z gorutyny\n")
        _, err := ioutil.ReadFile("/proc/net/tcp")
        if err != nil {
                log.Fatalf("nie moge czytac net/tcp: %v", err)
        }

        ifaces, _ := net.Interfaces()
        for _, iff := range ifaces {
                fmt.Println(iff)
        }

        wg.Done()

}
func main() {
        var wg sync.WaitGroup
        wg.Add(1)
        go func(wg *sync.WaitGroup) {
                defer wg.Done()
                // Lock the OS Thread so we don't accidentally switch namespaces
                runtime.LockOSThread()
                defer runtime.UnlockOSThread()

                // Save the current network namespace
                origns, _ := netns.Get()
                defer origns.Close()

                ns, err := netns.GetFromName("box")
                if err != nil {
                        log.Fatalf("GetFromName error: %v", err)
                }

                err = netns.Set(ns)
                if err != nil {
                        log.Fatalf("Cant set ns: %v", err)
                }

                _, err = ioutil.ReadFile("/proc/net/tcp")
                if err != nil {
                        log.Fatalf("nie moge czytac net/tcp: %v", err)
                }

                // Do something with the network namespace
                ifaces, _ := net.Interfaces()
                for _, iff := range ifaces {
                        fmt.Println(iff)
                }
                fmt.Printf("Interfaces: %v\n", ifaces)

                // Switch back to the original namespace
                netns.Set(origns)
        }(&wg)

        wg.Wait()

        for i := 0; i < 10; i++ {
                wg.Add(1)
                go readInterfaces(&wg)
                wg.Wait()
        }
}