HydPy February Container Snippet

container.py

import os
import sys
import unshare
import random
import string
import cgroups

if len(sys.argv) == 1:
    print(f"Usage {sys.argv[0]} cmd args")
    sys.exit(1)

cmd = sys.argv[1]
args = sys.argv[1:]
container_id = ''.join([random.choice(string.ascii_lowercase + string.digits) for _ in range(12)])

BASE_PATH = "/home/shubham1172/Workspace/rootfs"

cg = cgroups.Cgroup(container_id)
cg.set_memory_limit(10)
cg.set_cpu_limit(0.2)

unshare.unshare(unshare.CLONE_NEWUTS | unshare.CLONE_NEWPID)

pid = os.fork()
if pid == 0:
    # child process
    os.system(f'hostname {container_id}')
    cg.add(os.getpid())
    os.chroot(BASE_PATH)
    os.chdir('/')
    os.system('mount -t proc proc /proc')
    print(f"(pid {os.getpid()}) executing {cmd} with args: {args}")
    os.execv(cmd, args)
else:
    # parent process
    os.waitpid(pid, 0)
    os.system(f'umount {BASE_PATH}/proc')
    cg.delete()
    print(f"(pid {os.getpid()}) child terminated")