lxcsu

   1 #!/usr/bin/python
   2
   3
   4 import setns
   5 import os
   6 import sys
   7
   8 #from optparse import OptionParser
   9
  10 drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'.split(',')
  11
  12 """
  13 parser = OptionParser()
  14 parser.add_option("-n", "--net",
  15                   action="store_true", dest="netns", default=False,
  16                   help="Enter network namespace")
  17 parser.add_option("-m", "--mnt",
  18                   action="store_true", dest="mntns", default=False,
  19                   help="Enter mount namespace")
  20 parser.add_option("-p", "--pid",
  21                   action="store_true", dest="pidns", default=False,
  22                   help="Enter pid namespace")
  23
  24 (options, args) = parser.parse_args()
  25 """
  26 args = sys.argv[1:]
  27
  28 try:
  29         slice_name = args[0]
  30 except IndexError:
  31         print "You must specify a vm name"
  32         exit(1)
  33
  34 try:
  35         cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
  36         output = os.popen(cmd).readlines()
  37 except:
  38         print "Error finding slice %s"%slice_name
  39         exit(1)
  40
  41 slice_spec = None
  42 for e in output:
  43         try:
  44                 l = e.rstrip()
  45                 path = l.split(':')[0]
  46                 comp = l.rsplit(':')[-1]
  47                 slice_name_check = comp.rsplit('/')[-1]
  48
  49                 if (slice_name_check == slice_name):
  50                         slice_path = path
  51                         pid = slice_path.split('/')[2]
  52                         cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
  53                         if (cmdline == '/sbin/init'):
  54                                 slice_spec = slice_path
  55                                 break
  56         except:
  57                 break
  58
  59 if (not slice_spec or not pid):
  60     print "Not started: %s"%slice_name
  61     exit(1)
  62
  63 # Enter cgroups
  64 try:
  65     for subsystem in ['cpuset','memory','blkio']:
  66         open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
  67
  68 except:
  69     print "Error assigning resources: %s"%slice_name
  70     exit(1)
  71
  72 # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
  73 # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
  74 # in this case to error out the shell. (an alternative would be to un-freeze it,
  75 # add the task, and re-freeze it)
  76 try:
  77     f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
  78     f.write(str(os.getpid()))
  79     # note: we need to call f.close() explicitly, or we'll get an exception in
  80     # the object destructor, which will not be caught
  81     f.close()
  82 except:
  83     print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
  84     exit(1)
  85
  86 r1 = setns.chcontext('/proc/%s/ns/uts'%pid)
  87
  88 r2 = setns.chcontext('/proc/%s/ns/ipc'%pid)
  89 r3 = setns.chcontext('/proc/%s/ns/net'%pid)
  90
  91 open('/proc/lxcsu','w').write(pid)
  92 open('/proc/pidsu','w').write(pid)
  93
  94 pid = os.fork()
  95
  96 cap_args = map(lambda c:'--drop='+c, drop_capabilities)
  97
  98 if (pid == 0):
  99     os.execv('/usr/sbin/capsh',cap_args+['--','--login']+args[1:])
 100 else:
 101     os.waitpid(pid,0)