#!/usr/bin/python import sys import os import setns import pdb import re from argparse import ArgumentParser # can set to True here, but also use the -d option debug = False def getarch(f): output = os.popen('readelf -h %s 2>&1'%f).readlines() 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 get_cgroup_subdirs_for_pid(pid): cgroup_info_file = '/proc/%s/cgroup'%pid cgroup_lines = open(cgroup_info_file).read().splitlines() subdirs = {} for line in cgroup_lines: try: _, cgroup_name, subdir = line.split(':') subdirs[cgroup_name] = subdir except Exception, e: print "Error reading cgroup info: %s"%str(e) pass return subdirs def umount(fs_dir, opts=''): output = os.popen('/bin/umount %s %s 2>&1'%(opts, fs_dir)).read() return ('device is busy' not in output) def kvmsu(slice_name, args): mac_addresses = [] # Find MAC addresses of virt interfaces p = os.popen("virsh domiflist %s"%slice_name) for line in p: m = re.search(r'([0-9A-F]{2}[:-]){5}([0-9A-F]{2})', line, re.I) if m: mac_addresses.append(m.group()) # Find IP address of a reachable virt interface # Here we're taking the one attached to br-nat, but this is specific to OpenCloud ip_addr = None try: f = open('/var/lib/dnsmasq/br-nat.hosts', 'r') for line in f: for mac in mac_addresses: m = re.search("^%s,[0-9.]+$"%mac, line, re.I) if m: ip_addr = m.group().split(',')[1] break f.close() except: pass if ip_addr: # Need to login to a Ubuntu Cloud image as 'ubuntu' user # Not sure how to make this more general os.execv('/usr/bin/ssh', ['/usr/bin/ssh','-o','StrictHostKeyChecking=no','ubuntu@%s'%ip_addr] + args.command_to_run) else: # What should happen here? print "Cannot map instance to IP address" exit(1) def lxcsu(slice_name, args): # plain lxcsu if not args.internal: # no command given: enter interactive shell if not args.command_to_run: args.command_to_run=['/bin/sh'] args.command_to_run = [ '-c' ] + [" ".join(args.command_to_run)] # support for either setting debug at the top of this file, or on the command-line if args.debug: global debug debug=True try: cmd = '/usr/bin/virsh --connect lxc:/// domid %s'%slice_name # convert to int as a minimal raincheck driver_pid = int(os.popen(cmd).read().strip()) # locate the pid for the - expected - single child, that would be the init for that VM #init_pid = int(open("/proc/%s/task/%s/children"%(driver_pid,driver_pid)).read().strip()) init_pid = int(os.popen('pgrep -P %s'%driver_pid).readlines()[0].strip()) # Thierry: I am changing the code below to use child_pid instead of driver_pid # for the namespace handling features, that I was able to check # I've left the other ones as they were, i.e. using driver_pid, but I suspect # they chould be changed as well except: print "Domain %s not found"%slice_name exit(1) if not driver_pid or not init_pid: print "Domain %s not started"%slice_name exit(1) if debug: print "Found driver_pid",driver_pid,'and init_pid=',init_pid # xxx probably init_pid here too arch = getarch('/proc/%s/exe'%driver_pid) # Set sysctls specific to slice sysctls = [] sysctl_dir = '/etc/planetlab/vsys-attributes/%s'%slice_name if (os.access(sysctl_dir,0)): entries = os.listdir(sysctl_dir) for e in entries: prefix = 'vsys_sysctl.' if (e.startswith(prefix)): sysctl_file = '/'.join([sysctl_dir,e]) sysctl_name = e[len(prefix):] sysctl_val = open(sysctl_file).read() sysctls.append((sysctl_file, sysctl_name, sysctl_val)) # xxx probably init_pid here too subdirs = get_cgroup_subdirs_for_pid(driver_pid) sysfs_root = '/sys/fs/cgroup' # 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) # Enter cgroups current_cgroup = '' for subsystem in ['cpuset','memory','blkio','cpuacct','cpuacct,cpu','freezer']: try: current_cgroup = subsystem # There seems to be a bug in the cgroup schema: cpuacct,cpu can become cpu,cpuacct # We need to handle both task_path_alt = None try: subsystem_comps = subsystem.split(',') subsystem_comps.reverse() subsystem_alt = ','.join(subsystem_comps) tasks_path_alt = [sysfs_root, subsystem_alt, subdirs[subsystem], 'tasks'] except Exception,e: pass tasks_path = [sysfs_root,subsystem,subdirs[subsystem],'tasks'] tasks_path_str = '/'.join(tasks_path) try: f = open(tasks_path_str, 'w') except: tasks_path_alt_str = '/'.join(tasks_path_alt) f = open(tasks_path_alt_str, 'w') f.write(str(os.getpid())) if (subsystem=='freezer'): f.close() except Exception,e: if (not subdirs.has_key(subsystem)): pass else: if debug: print e print "Error assigning cgroup %s (pid=%s) for slice %s"%(current_cgroup,driver_pid, slice_name) exit(1) def chcontext (path): retcod = setns.chcontext (path) if retcod != 0: print 'WARNING - setns(%s)=>%s (ignored)'%(path,retcod) return retcod # Use init_pid and not driver_pid to locate reference namespaces ref_ns = "/proc/%s/ns/"%init_pid if True: chcontext(ref_ns+'uts') if True: chcontext(ref_ns+'ipc') if (not args.no_pidns): chcontext(ref_ns+'pid') if (not args.no_netns): chcontext(ref_ns+'net') if (not args.no_mntns): chcontext(ref_ns+'mnt') proc_mounted = False if (not os.access('/proc/self',0)): proc_mounted = True setns.proc_mount() for (sysctl_file, sysctl_name, sysctl_val) in sysctls: for fn in ["/sbin/sysctl", "/usr/sbin/sysctl", "/bin/sysctl", "/usr/bin/sysctl"]: if os.path.exists(fn): os.system('%s -w %s=%s >/dev/null 2>&1'%(fn, sysctl_name,sysctl_val)) break else: print "Error: image does not have a sysctl binary" # cgroups is not yet LXC-safe, so we need to use the coarse 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','systemd']: fs_path = '/sys/fs/cgroup/%s'%subsystem if (not umount(fs_path,'-l')): print 'WARNING - umount failed (ignored) with path=',fs_path pass # Leaving these comments for historical reference #print "Error disabling cgroup access" #exit(1) - Don't need this because failure here implies failure in the call to umount /sys/fs/cgroup if (not umount('/sys/fs/cgroup')): print "Error disabling cgroup access" exit(1) fork_pid = os.fork() def getuid (slicename): import pwd try: return pwd.getpwnam(slicename).pw_uid except: return if (fork_pid == 0): if (not args.root): setns.drop_caps() if (args.nosliceuid): # we still want to drop capabilities, but don't want to switch UIDs exec_args = [arch,'/bin/sh','--login',]+args.command_to_run else: # let's keep this check even though we don't use the uid # as a way of checking the existence of the slice account uid = getuid (slice_name) if not uid: print "lxcsu could not spot %s in /etc/passwd - exiting"%slice_name exit(1) exec_args = [arch,'/usr/bin/sudo','-u',slice_name,'/bin/sh','--login',]+args.command_to_run # once we can drop f12, it would be nicer to instead go for # exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--login',]+args.command_to_run else: exec_args = [arch,'/bin/sh','--login']+args.command_to_run os.environ['SHELL'] = '/bin/sh' if os.path.exists('/etc/planetlab/lib/bind_public.so'): os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so' if not args.noslicehome: os.environ['HOME'] = '/home/%s'%slice_name os.chdir("/home/%s"%(slice_name)) if debug: print 'lxcsu:execv:','/usr/bin/setarch',exec_args os.execv('/usr/bin/setarch',exec_args) else: setns.proc_umount() _,status = os.waitpid(fork_pid,0) exit(os.WEXITSTATUS(status)) def main (): parser = ArgumentParser() parser.add_argument("-n", "--nonet", action="store_true", dest="no_netns", default=False, help="Don't enter network namespace") parser.add_argument("-m", "--nomnt", action="store_true", dest="no_mntns", default=False, help="Don't enter mount namespace") parser.add_argument("-p", "--nopid", action="store_true", dest="no_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("-i","--internal", action="store_true", dest="internal", default=False, help="does *not* prepend '-- -c' to arguments - or invoke lxcsu-internal") parser.add_argument("-d","--debug", action='store_true', dest='debug', default=False, help="debug option") parser.add_argument("-s","--nosliceuid", action='store_true', dest="nosliceuid", default=False, help="do not change to slice uid inside of slice") parser.add_argument("-o","--noslicehome", action='store_true', dest="noslicehome", default=False, help="do not change to slice home directory inside of slice") if os.path.exists("/etc/lxcsu_default"): defaults = parser.parse_args(file("/etc/lxcsu_default","r").read().split()) parser.set_defaults(**defaults.__dict__) parser.add_argument ("slice_name") parser.add_argument ("command_to_run",nargs="*") args = parser.parse_args() slice_name=args.slice_name # unless we run the symlink 'lxcsu-internal', or we specify the -i option, prepend '--' '-c' if sys.argv[0].find('internal')>=0: args.internal=True if len(args.command_to_run)>0 and (args.command_to_run[0] == "/sbin/service"): # A quick hack to support nodemanager interfaces.py when restarting # networking in a slice. args.nosliceuid = True try: cmd = '/usr/bin/virsh dominfo %s'%slice_name info = os.popen(cmd).read() d = {} ostype = None for line in info.split('\n'): pair = line.split(':') d[pair[0].strip()] = pair[1].strip() if (pair[0].strip()=='OS Type'): ostype = pair[1].strip() break except: print "Domain %s not found"%slice_name is_kvm = ostype=='hvm' if (is_kvm): kvmsu(slice_name, args) else: lxcsu(slice_name, args) if __name__ == '__main__': main()