lxc-shutdown

#! /usr/bin/env python

import sys, os, signal, getopt, time

base_cgroup = "/cgroup"

def get_pids(name):
    pids = open(os.path.join(base_cgroup, name, "tasks")).read().split()
    return pids

def find_init(name):
    pids = get_pids(name)

    inits = []
    
    for p in pids:
        try:
            exe = os.readlink("/proc/%s/exe" % p)
        except OSError:
            continue
        
        if exe=="/sbin/init":
            inits.append(p)

    if not inits:
        raise RuntimeError("could not find '/sbin/init'")

    if len(inits)>1:
        raise RuntimeError("more than one '/sbin/init' found")

    return int(inits[0]), "/sbin/init"

    

def shutdown(name):
    init, exe = find_init(name)
    
    print "sending SIGINT (ctrl-alt-del) to %s (%s) in container %s" % (exe, init, name)
    
    os.kill(init, signal.SIGINT)
    try:
        print "processes running in %s:" % name, 
        for x in range(60):
            num = len(get_pids(name))
            print num,
            sys.stdout.flush()
            if num==1:
                break
            time.sleep(1)
    finally:
        os.system("lxc-stop -n %s" % (name, ))

def usage():
    print "lxc-shutdown -n NAME"
    print "    send SIGINT to /sbin/init in container NAME and wait for all processes besides init to finish"
    sys.exit(0)
    
def main():
    try:
        opts, args = getopt.getopt(sys.argv[1:], "n:", ["name="])
    except getopt.GetoptError, err:
        print str(err)
        sys.exit(10)

    name = None
        
    for o, a in opts:
        if o in ("-n", "--name"):
            name = a

    if not name:
        usage()

    shutdown(name)

    
    
if __name__=="__main__":
    main()