save

#!/usr/bin/env python3
import os
import subprocess
import sys

def run_cmd(cmd, silent=False):
    if silent:
        # CRIU shows errors even when it works. Suppress it.
        return subprocess.check_call(cmd, shell=True,
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL)  
    else:
        return subprocess.check_call(cmd, shell=True)

if not len(sys.argv) == 2:
    print('Usage: save dirname')
    sys.exit(1)

savename = sys.argv[1]
savedir = savename
if not savedir.startswith('/'):
    savedir = '/saves/' + savedir

# get tmux pid
try:
    pid = subprocess.check_output(["pidof", "tmux"])
    pid = pid.decode("ascii").strip()
except:
    pid = None

if pid is None:
    print('No tmux process found - cannot save.')
    sys.exit(2)
elif len(pid.split()) > 1:
    print('Found multiple tmux pids: [{}]. Detach from tmux before running save-to.'.format(pid))
    sys.exit(3)


# check exists
if os.path.isdir(savedir):
    response = input('Overwrite "{}" (y/n)? '.format(savedir))
    if response.lower() not in ['y', 'yes']:
        print('Save aborted.')
        sys.exit(0)
    else:
        run_cmd('rm -rf {}'.format(savedir))  # good thing we're in a container

# create dir if needed
if not os.path.isdir(savedir):
    os.mkdir(savedir)

# save
run_cmd("criu dump --leave-running --tree {} --images-dir {}".format(pid, savedir), silent=True)
print('Saved to {}.'.format(savedir))
print('Resume your game with "tmux attach".'.format(savedir))