8 from argparse import ArgumentParser
10 # can set to True here, but also use the -d option
15 exe_filename = '/proc/%s/exe' % pid
16 output = os.popen('readelf -h %s 2>&1' % exe_filename).readlines()
17 classlines = [x for x in output if ('Class' in x.split(':')[0])]
19 c = line.split(':')[1]
25 raise Exception('Could not determine architecture for pid %s' % pid)
28 def get_cgroup_subdirs_for_pid(pid):
29 cgroup_info_file = '/proc/%s/cgroup' % pid
30 cgroup_lines = open(cgroup_info_file).read().splitlines()
33 for line in cgroup_lines:
35 _, cgroup_name, subdir = line.split(':')
36 subdirs[cgroup_name] = subdir
37 except Exception as e:
38 print("Error reading cgroup info: %s" % str(e))
44 def umount(fs_dir, opts=''):
45 output = os.popen('/bin/umount %s %s 2>&1' % (opts, fs_dir)).read()
46 return ('device is busy' not in output)
50 parser = ArgumentParser()
51 parser.add_argument("-n", "--nonet",
52 action="store_true", dest="no_netns", default=False,
53 help="Don't enter network namespace")
54 parser.add_argument("-m", "--nomnt",
55 action="store_true", dest="no_mntns", default=False,
56 help="Don't enter mount namespace")
57 parser.add_argument("-p", "--nopid",
58 action="store_true", dest="no_pidns", default=False,
59 help="Don't enter pid namespace")
60 parser.add_argument("-r", "--root",
61 action="store_true", dest="root", default=False,
62 help="Enter as root: be careful")
63 parser.add_argument("-i", "--internal",
64 action="store_true", dest="internal", default=False,
65 help="does *not* prepend '-- -c' to arguments - or invoke lxcsu-internal")
66 parser.add_argument("-d", "--debug",
67 action='store_true', dest='debug', default=False,
69 parser.add_argument("-s", "--nosliceuid",
70 action='store_true', dest="nosliceuid", default=False,
71 help="do not change to slice uid inside of slice")
72 parser.add_argument("-o", "--noslicehome",
73 action='store_true', dest="noslicehome", default=False,
74 help="do not change to slice home directory inside of slice")
76 if os.path.exists("/etc/lxcsu_default"):
77 defaults = parser.parse_args(
78 file("/etc/lxcsu_default", "r").read().split())
79 parser.set_defaults(**defaults.__dict__)
81 parser.add_argument("slice_name")
82 parser.add_argument("command_to_run", nargs="*")
84 args = parser.parse_args()
85 slice_name = args.slice_name
87 # support for either setting debug at the top of this file, or on the command-line
92 # somehow some older nodes won't be able to find the login name in /etc/passwd
93 # when this is done down the road, so compute slice_uid while in a safe env
94 # even though we don't use the slice_uid any more, this is still
95 # checked later on as a means to ensure existence of the slice account
97 slice_uid = pwd.getpwnam(slice_name).pw_uid
98 except Exception as e:
101 print('error while computing slice_uid', e)
102 traceback.print_exc()
105 # unless we run the symlink 'lxcsu-internal', or we specify the -i option, prepend '--' '-c'
106 if sys.argv[0].find('internal') >= 0:
109 if len(args.command_to_run) > 0 and (args.command_to_run[0] == "/sbin/service"):
110 # A quick hack to support nodemanager interfaces.py when restarting
111 # networking in a slice.
112 args.nosliceuid = True
115 if not args.internal:
116 # no command given: enter interactive shell
117 if not args.command_to_run:
118 args.command_to_run = ['/bin/sh']
119 args.command_to_run = ['-c'] + [" ".join(args.command_to_run)]
122 cmd = '/usr/bin/virsh --connect lxc:/// domid %s' % slice_name
123 # convert to int as a minimal raincheck
124 driver_pid = int(os.popen(cmd).read().strip())
125 # locate the pid for the - expected - single child, that would be the init for that VM
126 #init_pid = int(open("/proc/%s/task/%s/children"%(driver_pid,driver_pid)).read().strip())
127 init_pid = int(os.popen('pgrep -P %s' %
128 driver_pid).readlines()[0].strip())
129 # Thierry: I am changing the code below to use init_pid instead of driver_pid
130 # for the namespace handling features, that I was able to check
131 # I've left the other ones as they were, i.e. using driver_pid, but I suspect
132 # some should be changed as well
135 print("Domain %s not found" % slice_name)
138 if not driver_pid or not init_pid:
139 print("Domain %s not started" % slice_name)
143 print("Found driver_pid", driver_pid, 'and init_pid=', init_pid)
144 # driver_pid is always x86_64, we need to look at the VM's init process here
145 arch = getarch(init_pid)
147 # Set sysctls specific to slice
149 sysctl_dir = '/etc/planetlab/vsys-attributes/%s' % slice_name
150 if (os.access(sysctl_dir, 0)):
151 entries = os.listdir(sysctl_dir)
153 prefix = 'vsys_sysctl.'
154 if (e.startswith(prefix)):
155 sysctl_file = '/'.join([sysctl_dir, e])
156 sysctl_name = e[len(prefix):]
157 sysctl_val = open(sysctl_file).read()
158 sysctls.append((sysctl_file, sysctl_name, sysctl_val))
160 # xxx probably init_pid here too
161 subdirs = get_cgroup_subdirs_for_pid(driver_pid)
162 sysfs_root = '/sys/fs/cgroup'
164 # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
165 # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
166 # in this case to error out the shell. (an alternative would be to un-freeze it,
167 # add the task, and re-freeze it)
170 for subsystem in ['cpuset', 'memory', 'blkio', 'cpuacct', 'cpuacct,cpu', 'freezer']:
172 current_cgroup = subsystem
174 # There seems to be a bug in the cgroup schema: cpuacct,cpu can become cpu,cpuacct
175 # We need to handle both
178 subsystem_comps = subsystem.split(',')
179 subsystem_comps.reverse()
180 subsystem_alt = ','.join(subsystem_comps)
181 tasks_path_alt = [sysfs_root, subsystem_alt,
182 subdirs[subsystem], 'tasks']
183 except Exception as e:
186 tasks_path = [sysfs_root, subsystem, subdirs[subsystem], 'tasks']
187 tasks_path_str = '/'.join(tasks_path)
190 f = open(tasks_path_str, 'w')
192 tasks_path_alt_str = '/'.join(tasks_path_alt)
193 f = open(tasks_path_alt_str, 'w')
195 f.write(str(os.getpid()))
196 if (subsystem == 'freezer'):
199 except Exception as e:
200 if (subsystem not in subdirs):
205 print("Error assigning cgroup %s (pid=%s) for slice %s" %
206 (current_cgroup, driver_pid, slice_name))
210 retcod = setns.chcontext(path)
212 print('WARNING - setns(%s)=>%s (ignored)' % (path, retcod))
215 # Use init_pid and not driver_pid to locate reference namespaces
216 ref_ns = "/proc/%s/ns/" % init_pid
219 chcontext(ref_ns+'uts')
221 chcontext(ref_ns+'ipc')
223 if (not args.no_pidns):
224 chcontext(ref_ns+'pid')
225 if (not args.no_netns):
226 chcontext(ref_ns+'net')
227 if (not args.no_mntns):
228 chcontext(ref_ns+'mnt')
231 if (not os.access('/proc/self', 0)):
235 for (sysctl_file, sysctl_name, sysctl_val) in sysctls:
236 for fn in ["/sbin/sysctl", "/usr/sbin/sysctl", "/bin/sysctl", "/usr/bin/sysctl"]:
237 if os.path.exists(fn):
238 os.system('%s -w %s=%s >/dev/null 2>&1' %
239 (fn, sysctl_name, sysctl_val))
242 print("Error: image does not have a sysctl binary")
244 # cgroups is not yet LXC-safe, so we need to use the coarse grained access control
245 # strategy of unmounting the filesystem
248 for subsystem in ['cpuset', 'cpu,cpuacct', 'memory', 'devices', 'freezer', 'net_cls', 'blkio', 'perf_event', 'systemd']:
249 fs_path = '/sys/fs/cgroup/%s' % subsystem
250 if (not umount(fs_path, '-l')):
251 print('WARNING - umount failed (ignored) with path=', fs_path)
253 # Leaving these comments for historical reference
254 # print "Error disabling cgroup access"
255 # exit(1) - Don't need this because failure here implies failure in the call to umount /sys/fs/cgroup
257 if (not umount('/sys/fs/cgroup')):
258 print("Error disabling cgroup access")
266 if (args.nosliceuid):
267 # we still want to drop capabilities, but don't want to switch UIDs
268 exec_args = [arch, '/bin/sh', '--login', ]+args.command_to_run
271 print("lxcsu could not spot %s in /etc/passwd - exiting" %
274 exec_args = [arch, '/usr/bin/sudo', '-u', slice_name,
275 '/bin/sh', '--login', ]+args.command_to_run
276 # once we can drop f12, it would be nicer to instead go for
277 # exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--login',]+args.command_to_run
279 exec_args = [arch, '/bin/sh', '--login']+args.command_to_run
281 os.environ['SHELL'] = '/bin/sh'
282 if os.path.exists('/etc/planetlab/lib/bind_public.so'):
283 os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so'
284 if not args.noslicehome:
285 os.environ['HOME'] = '/home/%s' % slice_name
286 os.chdir("/home/%s" % (slice_name))
288 print('lxcsu:execv:', '/usr/bin/setarch', exec_args)
289 os.execv('/usr/bin/setarch', exec_args)
292 _, status = os.waitpid(fork_pid, 0)
293 exit(os.WEXITSTATUS(status))
296 if __name__ == '__main__':