firecracker-netns/cmd/main.go

//go:build linux

package main

import (
	"antoine-roux.tk/projects/go/firecracker-netns/internal/netlink"
	"antoine-roux.tk/projects/go/firecracker-netns/internal/netns"
	"fmt"
	"net"
	"os"
	"os/exec"
	"runtime"
)

func setupEnv() int {
	newNs, err := netns.New()
	if err != nil {
		fmt.Println("new ns error", err)
		return 1
	}

	defer func(handle netns.NsHandle) {
		err := handle.Close()
		if err != nil {
			fmt.Println("close ns error", err)
		}
	}(newNs)

	defer func(ns netns.NsHandle) {
		err := netns.Delete(ns)
		if err != nil {
			fmt.Println("delete ns error", err)
		}
	}(newNs)

	vethPair, err := netlink.NewVirtualPairing(newNs, "wlp3s0")
	if err != nil {
		fmt.Println("new Veth error", err)
		return 1
	}

	defer func(veth *netlink.PairLink) {
		err = veth.DeleteVirtualPairing()
		if err != nil {
			fmt.Println("delete vethPair error", err)
		}
	}(vethPair)

	err = netns.Set(newNs)
	if err != nil {
		return 1
	}

	// Do something with the network namespace
	interfaces, _ := net.Interfaces()
	fmt.Printf("Interfaces: %v\n", interfaces)

	cmd := exec.Command("/bin/sh")

	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	cmd.Env = []string{"PS1=-[ns-process]- # "}

	if err := cmd.Run(); err != nil {
		fmt.Printf("Error running the /bin/sh command - %s\n", err)
		os.Exit(1)
	}

	return 0
}

func main() {
	// Lock the OS Thread, so we don't accidentally switch namespaces
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	os.Exit(setupEnv())
}