X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lxcsu;h=164344f70abfb55f948134a9213c3e3dfbdf315c;hb=13a56a4ff176386a815904f98f67aa5b75ed6b87;hp=24fcf4592140f923a7f089a328f9bf065487844d;hpb=6b7a68f13c328f74592f5397e362ff6cabe4f209;p=lxc-userspace.git diff --git a/lxcsu b/lxcsu index 24fcf45..164344f 100755 --- a/lxcsu +++ b/lxcsu @@ -3,63 +3,179 @@ import setns import os +import sys -from optparse import OptionParser - -drop_capabilities='cap_sys_admin,cap_net_admin,cap_sys_boot,cap_sys_module' - -parser = OptionParser() -parser.add_option("-n", "--net", - action="store_true", dest="netns", default=False, - help="Enter network namespace") -parser.add_option("-m", "--mnt", - action="store_true", dest="mntns", default=False, - help="Enter mount namespace") -parser.add_option("-p", "--pid", - action="store_true", dest="pidns", default=False, - help="Enter pid namespace") - -(options, args) = parser.parse_args() - -try: - slice_name = args[0] -except IndexError: - print "You must specify a vm name" - exit(1) - -try: - cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name - output = os.popen(cmd).readlines() -except: - print "Error finding slice %s"%slice_name - exit(1) - -slice_spec = None -for e in output: - try: - l = e.rstrip() - path = l.split(':')[0] - comp = l.rsplit(':')[-1] - slice_name_check = comp.rsplit('/')[-1] - - if (slice_name_check == slice_name): - slice_path = path - pid = slice_path.split('/')[2] - cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00') - if (cmdline == '/sbin/init'): - slice_spec = slice_path - break - except: - break - -if (not slice_spec or not pid): - print "Not started: %s"%slice_name - exit(1) - -r1 = setns.chcontext('/proc/%s/ns/utc'%pid) -r2 = setns.chcontext('/proc/%s/ns/ipc'%pid) -path = '/proc/%s/ns/net'%pid -r3 = setns.chcontext(path) -open('/proc/lxcsu','w').write(pid) -#os.system('mount none -t proc /proc') -os.execv('/usr/sbin/capsh',['--drop',drop_capabilities,'--']) +from argparse import ArgumentParser + +drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module' + +debug = False + +def getarch(f): + output = os.popen('readelf -h %s 2>&1'%f).readlines() + if debug: print "readelf output %s lines"%len(output) + classlines = [x for x in output if ('Class' in x.split(':')[0])] + line = classlines[0] + c = line.split(':')[1] + if ('ELF64' in c): + return 'x86_64' + elif ('ELF32' in c): + return 'i686' + else: + raise Exception('Could not determine architecture') + +def umount(fs_dir): + output = os.popen('/bin/umount %s 2>&1'%fs_dir).read() + return ('device is busy' not in fs_dir) + +def main (): + parser = ArgumentParser() + parser.add_argument("-n", "--nonet", + action="store_true", dest="netns", default=False, + help="Don't enter network namespace") + parser.add_argument("-m", "--nomnt", + action="store_true", dest="mntns", default=False, + help="Don't enter mount namespace") + parser.add_argument("-p", "--nopid", + action="store_true", dest="pidns", default=False, + help="Don't enter pid namespace") + parser.add_argument("-r", "--root", + action="store_true", dest="root", default=False, + help="Enter as root: be careful") + parser.add_argument("-d","--debug", + action='store_true', dest='debug', default=False, + help="debug option") + parser.add_argument ("slice_name") + parser.add_argument ("command_to_run",nargs="*") + + options = parser.parse_args() + slice_name=options.slice_name + global debug + debug=options.debug + + try: + cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name + output = os.popen(cmd).readlines() + if debug: print "output of grep freezer has %s lines"%len(output) + except: + print "Error finding slice %s"%slice_name + exit(1) + + slice_spec = None + + # provide a default as this is not always properly computed + arch = None + + for e in output: + try: + l = e.rstrip() + path = l.split(':')[0] + comp = l.rsplit(':')[-1] + slice_name_check = comp.rsplit('/')[-1] + if debug: print "dealing with >%s<"%slice_name_check + + if (slice_name_check == slice_name): + if debug: print "found %s"%slice_name + slice_path = path + pid = slice_path.split('/')[2] + cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00') + if (cmdline == '/sbin/init'): + slice_spec = slice_path + arch = getarch('/proc/%s/exe'%pid) + if debug: print "setting arch",arch + break + except Exception,e: + if debug: + import traceback + print "BEG lxcsu - ignoring exception" + traceback.print_exc() + print "END lxcsu - ignoring exception" + pass + + if (not slice_spec or not pid): + print "Not started: %s"%slice_name + exit(1) + + if arch is None: + arch = 'x86_64' + if debug: print "WARNING: setting arch to default x86_64" + + # Enter cgroups + try: + for subsystem in ['cpuset','memory','blkio']: + open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid())) + + except: + print "Error assigning resources: %s"%slice_name + exit(1) + + try: + open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid())) + except: + print "Error assigning cpuacct: %s" % slice_name + exit(1) + + # If the slice is frozen, then we'll get an EBUSY when trying to write to the task + # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best + # in this case to error out the shell. (an alternative would be to un-freeze it, + # add the task, and re-freeze it) + try: + f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w') + f.write(str(os.getpid())) + # note: we need to call f.close() explicitly, or we'll get an exception in + # the object destructor, which will not be caught + f.close() + except: + print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name + exit(1) + + setns.chcontext('/proc/%s/ns/uts'%pid) + setns.chcontext('/proc/%s/ns/ipc'%pid) + + if (not options.netns): + setns.chcontext('/proc/%s/ns/net'%pid) + + if (not options.mntns): + setns.chcontext('/proc/%s/ns/mnt'%pid) + + if (not options.pidns): + setns.chcontext('/proc/%s/ns/pid'%pid) + + if (not os.access('/proc/self',0)): + setns.proc_mount() + + # cgroups is not yet LXC-safe, so we need to use the course grained access control + # strategy of unmounting the filesystem + + umount_result = True + for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event']: + fs_path = '/sys/fs/cgroup/%s'%subsystem + if (not umount(fs_path)): + print "Error disabling cgroup access" + exit(1) + + if (not umount('/sys/fs/cgroup')): + print "Error disabling cgroup access" + exit(1) + + pid = os.fork() + + if (pid == 0): + cap_arg = '--drop='+drop_capabilities + + if (not options.root): + exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login']+options.command_to_run + else: + exec_args = [arch,'/usr/sbin/capsh','--','--login']+options.command_to_run + + if debug: + print "exec'ing" + for arg in exec_args: print ">%s<"%arg + os.environ['SHELL'] = '/bin/sh' + os.execv('/usr/bin/setarch',exec_args) + else: + _,status = os.waitpid(pid,0) + exit(os.WEXITSTATUS(status)) + +if __name__ == '__main__': + main()