8 from optparse import OptionParser
10 drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
13 output = os.popen('readelf -h %s 2>&1'%f).readlines()
14 classlines = [x for x in output if ('Class' in x.split(':')[0])]
16 c = line.split(':')[1]
22 raise Exception('Could not determine architecture')
25 output = os.popen('/bin/umount %s 2>&1'%fs_dir).read()
26 return ('device is busy' not in fs_dir)
28 parser = OptionParser()
29 parser.add_option("-n", "--nonet",
30 action="store_true", dest="netns", default=False,
31 help="Don't enter network namespace")
32 parser.add_option("-m", "--nomnt",
33 action="store_true", dest="mntns", default=False,
34 help="Don't enter mount namespace")
35 parser.add_option("-p", "--nopid",
36 action="store_true", dest="pidns", default=False,
37 help="Don't enter pid namespace")
38 parser.add_option("-r", "--root",
39 action="store_true", dest="root", default=False,
40 help="Enter as root: be careful")
42 (options, args) = parser.parse_args()
47 print "You must specify a vm name"
51 cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
52 output = os.popen(cmd).readlines()
54 print "Error finding slice %s"%slice_name
59 # xxx fixme xxx - provide a default as this is not always properly computed
65 path = l.split(':')[0]
66 comp = l.rsplit(':')[-1]
67 slice_name_check = comp.rsplit('/')[-1]
69 if (slice_name_check == slice_name):
71 pid = slice_path.split('/')[2]
72 cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
73 if (cmdline == '/sbin/init'):
74 slice_spec = slice_path
75 arch = getarch('/proc/%s/exe'%pid)
80 if (not slice_spec or not pid):
81 print "Not started: %s"%slice_name
86 for subsystem in ['cpuset','memory','blkio']:
87 open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
90 print "Error assigning resources: %s"%slice_name
94 open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid()))
96 print "Error assigning cpuacct: %s" % slice_name
99 # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
100 # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
101 # in this case to error out the shell. (an alternative would be to un-freeze it,
102 # add the task, and re-freeze it)
104 f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
105 f.write(str(os.getpid()))
106 # note: we need to call f.close() explicitly, or we'll get an exception in
107 # the object destructor, which will not be caught
110 print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
113 setns.chcontext('/proc/%s/ns/uts'%pid)
114 setns.chcontext('/proc/%s/ns/ipc'%pid)
116 if (not options.netns):
117 setns.chcontext('/proc/%s/ns/net'%pid)
119 if (not options.mntns):
120 open('/proc/lxcsu','w').write(pid)
122 if (not options.pidns):
123 open('/proc/pidsu','w').write(pid)
125 # cgroups is not yet LXC-safe, so we need to use the course grained access control
126 # strategy of unmounting the filesystem
129 for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event']:
130 fs_path = '/sys/fs/cgroup/%s'%subsystem
131 if (not umount(fs_path)):
132 print "Error disabling cgroup access"
135 if (not umount('/sys/fs/cgroup')):
136 print "Error disabling cgroup access"
142 cap_arg = '--drop='+drop_capabilities
144 if (not options.root):
145 exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login']+args[1:]
147 exec_args = [arch,'/usr/sbin/capsh','--','--login']+args[1:]
149 os.environ['SHELL'] = '/bin/sh'
150 os.execv('/usr/bin/setarch',exec_args)
152 _,status = os.waitpid(pid,0)
153 exit(os.WEXITSTATUS(status))