rd.py 文件源码

def contain(command, image_name, image_dir, container_id, container_dir):
    new_root = create_container_root(
        image_name, image_dir, container_id, container_dir)
    print('Created a new root fs for our container: {}'.format(new_root))

    # TODO: time to say goodbye to the old mount namespace,
    #       see "man 2 unshare" to get some help
    #   HINT 1: there is no os.unshare(), time to use the linux module we made
    #           just for you!
    #   HINT 2: the linux module includes both functions and constants!
    #           e.g. linux.CLONE_NEWNS

    # TODO: remember shared subtrees?
    # (https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt)
    # Make / a private mount to avoid littering our host mount table.

    # Create mounts (/proc, /sys, /dev) under new_root
    linux.mount('proc', os.path.join(new_root, 'proc'), 'proc', 0, '')
    linux.mount('sysfs', os.path.join(new_root, 'sys'), 'sysfs', 0, '')
    linux.mount('tmpfs', os.path.join(new_root, 'dev'), 'tmpfs',
                linux.MS_NOSUID | linux.MS_STRICTATIME, 'mode=755')
    # Add some basic devices
    devpts_path = os.path.join(new_root, 'dev', 'pts')
    if not os.path.exists(devpts_path):
        os.makedirs(devpts_path)
        linux.mount('devpts', devpts_path, 'devpts', 0, '')
    for i, dev in enumerate(['stdin', 'stdout', 'stderr']):
        os.symlink('/proc/self/fd/%d' % i, os.path.join(new_root, 'dev', dev))

    # TODO: add more devices (e.g. null, zero, random, urandom) using os.mknod.

    os.chroot(new_root)

    os.chdir('/')

    os.execvp(command[0], command)