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