Demo code to try out chroot using python context manager

chroot.py

import os
import sys
import shutil

class chroot:
    def __init__(self, root_dir):
        self.root_dir = root_dir

    def __enter__(self):
        self.real_root = os.open("/",os.O_RDONLY)
        folders = [ 'proc', 'sys', 'dev', 'home' ]
        
        for folder in folders:
            full_path = self.root_dir + "/" + folder
            
            if not os.path.exists(full_path):
                os.mkdir(full_path)

            os.system("mount --bind /%s %s" % (folder, full_path))
        os.chroot(self.root_dir)

    def __exit__(self, exc_type, exc_val, traceback):
        os.system("umount {/proc,/sys}")
        os.system("sync")
        os.fchdir(self.real_root)
        os.chroot('.')
        os.close(self.real_root)
        os.system("umount -l %s/home" % self.root_dir)
        os.system("umount -l %s/dev" % self.root_dir)


if __name__ == '__main__':
    with chroot("/mnt"):
        with open("/test.txt", "w") as f:
            f.write("hi\n")
            sys.exit(1)