make a simple container

createContainer.go

package main

import (
	"os"
	"os/exec"
	"syscall"
)

func must(err error) {
	if err != nil {
		panic(err)
	}
}

func main() {
	// need to make rootfs dir from linux OS file system
	// bellow is a sample to make rootfs dir from alpine
	// $ docker pull alpine
	// $ docker create --name alpine alpine
	// $ docker export alpine > alpine.tar
	// $ docker rm alpine
	// $ mkdir rootfs
	must(syscall.Chroot("./rootfs"))
	must(syscall.Chdir("/"))

	cmd := exec.Command("/bin/sh")
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.SysProcAttr = &syscall.SysProcAttr{
		Cloneflags: syscall.CLONE_NEWPID | syscall.CLONE_NEWUTS,
	}

	must(cmd.Run())
}