7 from argparse import ArgumentParser
9 drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
14 output = os.popen('readelf -h %s 2>&1'%f).readlines()
15 classlines = [x for x in output if ('Class' in x.split(':')[0])]
17 c = line.split(':')[1]
23 raise Exception('Could not determine architecture')
26 output = os.popen('/bin/umount %s 2>&1'%fs_dir).read()
27 return ('device is busy' not in output)
30 parser = ArgumentParser()
31 parser.add_argument("-n", "--nonet",
32 action="store_true", dest="netns", default=False,
33 help="Don't enter network namespace")
34 parser.add_argument("-m", "--nomnt",
35 action="store_true", dest="mntns", default=False,
36 help="Don't enter mount namespace")
37 parser.add_argument("-p", "--nopid",
38 action="store_true", dest="pidns", default=False,
39 help="Don't enter pid namespace")
40 parser.add_argument("-r", "--root",
41 action="store_true", dest="root", default=False,
42 help="Enter as root: be careful")
43 parser.add_argument("-d","--debug",
44 action='store_true', dest='debug', default=False,
46 parser.add_argument ("slice_name")
47 parser.add_argument ("command_to_run",nargs="*")
49 args = parser.parse_args()
50 slice_name=args.slice_name
51 # support for either setting debug at the top of this file, or on the command-line
57 cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
58 output = os.popen(cmd).readlines()
59 # if debug: print "output of grep freezer has %s lines"%len(output)
61 print "Error finding slice %s"%slice_name
66 # provide a default as this is not always properly computed
72 path = l.split(':')[0]
73 comp = l.rsplit(':')[-1]
74 slice_name_check = comp.rsplit('/')[-1]
75 if debug: print "dealing with >%s<"%slice_name_check
77 if (slice_name_check == slice_name):
78 if debug: print "found %s"%slice_name
80 pid = slice_path.split('/')[2]
81 cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
82 if (cmdline == '/sbin/init') or (cmdline.startswith("init [")):
83 slice_spec = slice_path
84 arch = getarch('/proc/%s/exe'%pid)
89 print "BEG lxcsu - ignoring exception"
91 print "END lxcsu - ignoring exception"
94 if (not slice_spec or not pid):
95 print "Not started: %s"%slice_name
101 # Set sysctls specific to slice
102 sysctl_dir = '/etc/planetlab/vsys-attributes/%s'%slice_name
103 if (os.access(sysctl_dir,0)):
104 entries = os.listdir(sysctl_dir)
106 prefix = 'vsys_sysctl.'
107 if (e.startswith(prefix)):
108 sysctl_file = '/'.join([sysctl_dir,e])
109 sysctl_name = e[len(prefix):]
110 sysctl_val = open(sysctl_file).read()
111 os.system('sysctl -w %s=%s'%(sysctl_name,sysctl_val))
115 for subsystem in ['cpuset','memory','blkio']:
116 open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
119 print "Error assigning resources: %s"%slice_name
123 open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid()))
125 print "Error assigning cpuacct: %s" % slice_name
128 # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
129 # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
130 # in this case to error out the shell. (an alternative would be to un-freeze it,
131 # add the task, and re-freeze it)
133 f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
134 f.write(str(os.getpid()))
135 # note: we need to call f.close() explicitly, or we'll get an exception in
136 # the object destructor, which will not be caught
139 print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
142 setns.chcontext('/proc/%s/ns/uts'%pid)
143 setns.chcontext('/proc/%s/ns/ipc'%pid)
146 setns.chcontext('/proc/%s/ns/pid'%pid)
149 setns.chcontext('/proc/%s/ns/net'%pid)
152 setns.chcontext('/proc/%s/ns/mnt'%pid)
157 if (not os.access('/proc/self',0)):
163 # cgroups is not yet LXC-safe, so we need to use the course grained access control
164 # strategy of unmounting the filesystem
167 for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event']:
168 fs_path = '/sys/fs/cgroup/%s'%subsystem
169 if (not umount(fs_path)):
170 print "Error disabling cgroup access"
173 if (not umount('/sys/fs/cgroup')):
174 print "Error disabling cgroup access"
180 cap_arg = '--drop='+drop_capabilities
183 exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--','--login',]+args.command_to_run
185 exec_args = [arch,'/usr/sbin/capsh','--','--login']+args.command_to_run
187 os.environ['SHELL'] = '/bin/sh'
188 os.environ['HOME'] = '/home/%s'%slice_name
189 os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so'
190 os.chdir("/home/%s"%(slice_name))
191 if debug: print 'lxcsu-internal:execv:','/usr/bin/setarch',exec_args
192 os.execv('/usr/bin/setarch',exec_args)
195 _,status = os.waitpid(pid,0)
196 exit(os.WEXITSTATUS(status))
198 if __name__ == '__main__':