8 from argparse import ArgumentParser
10 # can set to True here, but also use the -d option
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')
25 def get_cgroup_subdirs_for_pid(pid):
26 cgroup_info_file = '/proc/%s/cgroup'%pid
27 cgroup_lines = open(cgroup_info_file).read().splitlines()
30 for line in cgroup_lines:
32 _, cgroup_name, subdir = line.split(':')
33 subdirs[cgroup_name] = subdir
35 print "Error reading cgroup info: %s"%str(e)
41 def umount(fs_dir, opts=''):
42 output = os.popen('/bin/umount %s %s 2>&1'%(opts, fs_dir)).read()
43 return ('device is busy' not in output)
46 parser = ArgumentParser()
47 parser.add_argument("-n", "--nonet",
48 action="store_true", dest="no_netns", default=False,
49 help="Don't enter network namespace")
50 parser.add_argument("-m", "--nomnt",
51 action="store_true", dest="no_mntns", default=False,
52 help="Don't enter mount namespace")
53 parser.add_argument("-p", "--nopid",
54 action="store_true", dest="no_pidns", default=False,
55 help="Don't enter pid namespace")
56 parser.add_argument("-r", "--root",
57 action="store_true", dest="root", default=False,
58 help="Enter as root: be careful")
59 parser.add_argument("-i","--internal",
60 action="store_true", dest="internal", default=False,
61 help="does *not* prepend '-- -c' to arguments - or invoke lxcsu-internal")
62 parser.add_argument("-d","--debug",
63 action='store_true', dest='debug', default=False,
65 parser.add_argument("-s","--nosliceuid",
66 action='store_true', dest="nosliceuid", default=False,
67 help="do not change to slice uid inside of slice")
68 parser.add_argument("-o","--noslicehome",
69 action='store_true', dest="noslicehome", default=False,
70 help="do not change to slice home directory inside of slice")
72 if os.path.exists("/etc/lxcsu_default"):
73 defaults = parser.parse_args(file("/etc/lxcsu_default","r").read().split())
74 parser.set_defaults(**defaults.__dict__)
76 parser.add_argument ("slice_name")
77 parser.add_argument ("command_to_run",nargs="*")
79 args = parser.parse_args()
80 slice_name=args.slice_name
82 # unless we run the symlink 'lxcsu-internal', or we specify the -i option, prepend '--' '-c'
83 if sys.argv[0].find('internal')>=0: args.internal=True
85 if len(args.command_to_run)>0 and (args.command_to_run[0] == "/sbin/service"):
86 # A quick hack to support nodemanager interfaces.py when restarting
87 # networking in a slice.
88 args.nosliceuid = True
92 # no command given: enter interactive shell
93 if not args.command_to_run: args.command_to_run=['/bin/sh']
94 args.command_to_run = [ '-c' ] + [" ".join(args.command_to_run)]
96 # support for either setting debug at the top of this file, or on the command-line
102 cmd = '/usr/bin/virsh --connect lxc:/// domid %s'%slice_name
103 # convert to int as a minimal raincheck
104 driver_pid = int(os.popen(cmd).read().strip())
105 # locate the pid for the - expected - single child, that would be the init for that VM
106 #init_pid = int(open("/proc/%s/task/%s/children"%(driver_pid,driver_pid)).read().strip())
107 init_pid = int(os.popen('pgrep -P %s'%driver_pid).readlines()[0].strip())
108 # Thierry: I am changing the code below to use child_pid instead of driver_pid
109 # for the namespace handling features, that I was able to check
110 # I've left the other ones as they were, i.e. using driver_pid, but I suspect
111 # they chould be changed as well
114 print "Domain %s not found"%slice_name
117 if not driver_pid or not init_pid:
118 print "Domain %s not started"%slice_name
121 if debug: print "Found driver_pid",driver_pid,'and init_pid=',init_pid
122 # xxx probably init_pid here too
123 arch = getarch('/proc/%s/exe'%driver_pid)
125 # Set sysctls specific to slice
127 sysctl_dir = '/etc/planetlab/vsys-attributes/%s'%slice_name
128 if (os.access(sysctl_dir,0)):
129 entries = os.listdir(sysctl_dir)
131 prefix = 'vsys_sysctl.'
132 if (e.startswith(prefix)):
133 sysctl_file = '/'.join([sysctl_dir,e])
134 sysctl_name = e[len(prefix):]
135 sysctl_val = open(sysctl_file).read()
136 sysctls.append((sysctl_file, sysctl_name, sysctl_val))
138 # xxx probably init_pid here too
139 subdirs = get_cgroup_subdirs_for_pid(driver_pid)
140 sysfs_root = '/sys/fs/cgroup'
142 # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
143 # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
144 # in this case to error out the shell. (an alternative would be to un-freeze it,
145 # add the task, and re-freeze it)
148 for subsystem in ['cpuset','memory','blkio','cpuacct','cpuacct,cpu','freezer']:
150 current_cgroup = subsystem
152 # There seems to be a bug in the cgroup schema: cpuacct,cpu can become cpu,cpuacct
153 # We need to handle both
156 subsystem_comps = subsystem.split(',')
157 subsystem_comps.reverse()
158 subsystem_alt = ','.join(subsystem_comps)
159 tasks_path_alt = [sysfs_root, subsystem_alt, subdirs[subsystem], 'tasks']
163 tasks_path = [sysfs_root,subsystem,subdirs[subsystem],'tasks']
164 tasks_path_str = '/'.join(tasks_path)
167 f = open(tasks_path_str, 'w')
169 tasks_path_alt_str = '/'.join(tasks_path_alt)
170 f = open(tasks_path_alt_str, 'w')
172 f.write(str(os.getpid()))
173 if (subsystem=='freezer'):
177 if (not subdirs.has_key(subsystem)):
181 print "Error assigning cgroup %s (pid=%s) for slice %s"%(current_cgroup,driver_pid, slice_name)
185 def chcontext (path):
186 retcod = setns.chcontext (path)
188 print 'WARNING - setns(%s)=>%s (ignored)'%(path,retcod)
191 # Use init_pid and not driver_pid to locate reference namespaces
192 ref_ns = "/proc/%s/ns/"%init_pid
194 if True: chcontext(ref_ns+'uts')
195 if True: chcontext(ref_ns+'ipc')
197 if (not args.no_pidns): chcontext(ref_ns+'pid')
198 if (not args.no_netns): chcontext(ref_ns+'net')
199 if (not args.no_mntns): chcontext(ref_ns+'mnt')
202 if (not os.access('/proc/self',0)):
206 for (sysctl_file, sysctl_name, sysctl_val) in sysctls:
207 for fn in ["/sbin/sysctl", "/usr/sbin/sysctl", "/bin/sysctl", "/usr/bin/sysctl"]:
208 if os.path.exists(fn):
209 os.system('%s -w %s=%s >/dev/null 2>&1'%(fn, sysctl_name,sysctl_val))
212 print "Error: image does not have a sysctl binary"
214 # cgroups is not yet LXC-safe, so we need to use the coarse grained access control
215 # strategy of unmounting the filesystem
218 for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event','systemd']:
219 fs_path = '/sys/fs/cgroup/%s'%subsystem
220 if (not umount(fs_path,'-l')):
221 print 'WARNING - umount failed (ignored) with path=',fs_path
223 # Leaving these comments for historical reference
224 #print "Error disabling cgroup access"
225 #exit(1) - Don't need this because failure here implies failure in the call to umount /sys/fs/cgroup
227 if (not umount('/sys/fs/cgroup')):
228 print "Error disabling cgroup access"
233 def getuid (slicename):
236 return pwd.getpwnam(slicename).pw_uid
243 if (args.nosliceuid):
244 # we still want to drop capabilities, but don't want to switch UIDs
245 exec_args = [arch,'/bin/sh','--login',]+args.command_to_run
247 # let's keep this check even though we don't use the uid
248 # as a way of checking the existence of the slice account
249 uid = getuid (slice_name)
251 print "lxcsu could not spot %s in /etc/passwd - exiting"%slice_name
253 exec_args = [arch,'/usr/bin/sudo','-u',slice_name,'/bin/sh','--login',]+args.command_to_run
254 # once we can drop f12, it would be nicer to instead go for
255 # exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--login',]+args.command_to_run
257 exec_args = [arch,'/bin/sh','--login']+args.command_to_run
259 os.environ['SHELL'] = '/bin/sh'
260 if os.path.exists('/etc/planetlab/lib/bind_public.so'):
261 os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so'
262 if not args.noslicehome:
263 os.environ['HOME'] = '/home/%s'%slice_name
264 os.chdir("/home/%s"%(slice_name))
265 if debug: print 'lxcsu:execv:','/usr/bin/setarch',exec_args
266 os.execv('/usr/bin/setarch',exec_args)
269 _,status = os.waitpid(fork_pid,0)
270 exit(os.WEXITSTATUS(status))
272 if __name__ == '__main__':