X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lxcsu;h=90491870ebfad43dc9aa4f20112af17b7f73096e;hb=0a7a037c4d0c9cd5b23904da298080261fb60fcd;hp=4c4bc04ec6873a31e78443724c985ed01e9d43f6;hpb=c2b9fa70310e6fd5e55f70d69868254ee1881c9c;p=lxc-userspace.git

diff --git a/lxcsu b/lxcsu
index 4c4bc04..9049187 100755
--- a/lxcsu
+++ b/lxcsu
@@ -3,15 +3,16 @@
 import sys
 import os
 import setns
-import pdb
+import pwd
 
 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()
+def getarch(pid):
+    exe_filename='/proc/%s/exe'%pid
+    output = os.popen('readelf -h %s 2>&1'%exe_filename).readlines()
     classlines = [x for x in output if ('Class' in x.split(':')[0])]
     line = classlines[0]
     c = line.split(':')[1]
@@ -20,7 +21,7 @@ def getarch(f):
     elif ('ELF32' in c):
         return 'i686'
     else:
-        raise Exception('Could not determine architecture')
+        raise Exception('Could not determine architecture for pid %s'%pid)
 
 def get_cgroup_subdirs_for_pid(pid):
     cgroup_info_file = '/proc/%s/cgroup'%pid
@@ -79,6 +80,24 @@ def main ():
     args = parser.parse_args()
     slice_name=args.slice_name
 
+    # support for either setting debug at the top of this file, or on the command-line
+    if args.debug:
+        global debug
+	debug=True
+
+    # somehow some older nodes won't be able to find the login name in /etc/passwd 
+    # when this is done down the road, so compute slice_uid while in a safe env
+    # even though we don't use the slice_uid any more, this is still 
+    # checked later on as a means to ensure existence of the slice account
+    try:
+        slice_uid = pwd.getpwnam(slice_name).pw_uid
+    except Exception, e:
+        if debug:
+            import traceback
+            print 'error while computing slice_uid',e
+            traceback.print_exc()
+        slice_uid=None
+
     # 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
 
@@ -93,11 +112,6 @@ def main ():
 	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
@@ -105,10 +119,10 @@ def main ():
         # 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
+        # Thierry: I am changing the code below to use init_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
+        # some should be changed as well
 
     except:
         print "Domain %s not found"%slice_name
@@ -119,8 +133,8 @@ def main ():
 	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)
+    # driver_pid is always x86_64, we need to look at the VM's init process here
+    arch = getarch(init_pid)
 
     # Set sysctls specific to slice
     sysctls = []
@@ -230,13 +244,6 @@ def main ():
 
     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() 
@@ -244,10 +251,7 @@ def main ():
                 # 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:
+                if not slice_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