From 958a51c139fd55a18d8ba07923801fdffcd91cbf Mon Sep 17 00:00:00 2001
From: Sapan Bhatia <gwsapan@gmail.com>
Date: Wed, 19 Mar 2014 01:43:23 -0400
Subject: [PATCH] Replaced lxcsu with slicesu. The latter supports hypervisors
e.g. KVM
---
slicesu | 310 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 310 insertions(+)
create mode 100644 slicesu
diff --git a/slicesu b/slicesu
new file mode 100644
index 0000000..15e5854
--- /dev/null
+++ b/slicesu
@@ -0,0 +1,310 @@
+#!/usr/bin/python
+
+import sys
+import os
+import setns
+import pdb
+
+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):
+ # Find MAC address of virt interface
+ ifstr = os.popen('/usr/bin/virsh domiflist %s'%slice_name).read().strip()
+ mac_address = ifstr.split()[-1]
+
+ # Find IP address of virt interface
+ ipaddr_str = os.popen('arp -an | grep %s'%'78:2b:cb:2d:f0:60').read().strip()
+ ip_addr_part = ipaddr_str.split()[1]
+ if (ip_addr_part[0]=='(' and ip_addr_part[-1]==')'):
+ ip_addr = ip_addr_part[1:len(ip_addr_part)-1]
+
+ os.execv('/usr/bin/ssh',['/usr/bin/ssh','-o','StrictHostKeyChecking=no','root@%s'%ip_addr,'"$@"'])
+
+
+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()
--
2.47.0