-# $Id$
-# $URL$
-
"""A few things that didn't seem to fit anywhere else."""
-import os
+import os, os.path
import pwd
import tempfile
import fcntl
import errno
import threading
import subprocess
+import shutil
+import sys
import logger
os.setsid()
if os.fork() != 0: os._exit(0)
os.chdir('/')
- os.umask(0)
+ os.umask(0022)
devnull = os.open(os.devnull, os.O_RDWR)
os.dup2(devnull, 0)
# xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
def write_file(filename, do_write, **kw_args):
"""Write file <filename> atomically by opening a temporary file, using <do_write> to write that file, and then renaming the temporary file."""
- os.rename(write_temp_file(do_write, **kw_args), filename)
+ shutil.move(write_temp_file(do_write, **kw_args), filename)
def write_temp_file(do_write, mode=None, uidgid=None):
fd, temporary_filename = tempfile.mkstemp()
return temporary_filename
# replace a target file with a new contents - checks for changes
-# return True if a change occurred, in which case
-# chown/chmod settings should be taken care of
+# can handle chmod if requested
+# can also remove resulting file if contents are void, if requested
+# performs atomically:
+# writes in a tmp file, which is then renamed (from sliverauth originally)
+# returns True if a change occurred, or the file is deleted
def replace_file_with_string (target, new_contents, chmod=None, remove_if_empty=False):
try:
current=file(target).read()
if current==new_contents:
# if turns out to be an empty string, and remove_if_empty is set,
# then make sure to trash the file if it exists
- if remove_if_empty and os.path.isfile(target):
+ if remove_if_empty and not new_contents and os.path.isfile(target):
+ logger.verbose("tools.replace_file_with_string: removing file %s"%target)
try: os.unlink(target)
finally: return True
return False
- # overwrite target file
- f=file(target,'w')
- f.write(new_contents)
- f.close()
+ # overwrite target file: create a temp in the same directory
+ path=os.path.dirname(target) or '.'
+ fd, name = tempfile.mkstemp('','repl',path)
+ os.write(fd,new_contents)
+ os.close(fd)
+ if os.path.exists(target):
+ os.unlink(target)
+ shutil.move(name,target)
if chmod: os.chmod(target,chmod)
return True
-# not needed yet - should that unlink the new file ?
-#def replace_file_with_file (target, new):
-# return replace_file_with_string (target, file(new).read())
####################
# utilities functions to get (cached) information from the node
def release(self):
logger.log("tools: Lock released.", 2)
fcntl.lockf(self.fd, fcntl.LOCK_UN)
+
+####################
+# Utilities for getting the IP address of a LXC/Openvswitch slice. Do this by
+# running ifconfig inside of the slice's context.
+
+def get_sliver_process(slice_name, process_cmdline):
+ """ Utility function to find a process inside of an LXC sliver. Returns
+ (cgroup_fn, pid). cgroup_fn is the filename of the cgroup file for
+ the process, for example /proc/2592/cgroup. Pid is the process id of
+ the process. If the process is not found then (None, None) is returned.
+ """
+ try:
+ cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
+ output = os.popen(cmd).readlines()
+ except:
+ # the slice couldn't be found
+ logger.log("get_sliver_process: couldn't find slice %s" % slice_name)
+ return (None, None)
+
+ cgroup_fn = None
+ pid = 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 == process_cmdline):
+ cgroup_fn = slice_path
+ break
+ except:
+ break
+
+ if (not cgroup_fn) or (not pid):
+ logger.log("get_sliver_process: process %s not running in slice %s" % (process_cmdline, slice_name))
+ return (None, None)
+
+ return (cgroup_fn, pid)
+
+def get_sliver_ifconfig(slice_name, device="eth0"):
+ """ return the output of "ifconfig" run from inside the sliver.
+
+ side effects: adds "/usr/sbin" to sys.path
+ """
+
+ # See if setns is installed. If it's not then we're probably not running
+ # LXC.
+ if not os.path.exists("/usr/sbin/setns.so"):
+ return None
+
+ # setns is part of lxcsu and is installed to /usr/sbin
+ if not "/usr/sbin" in sys.path:
+ sys.path.append("/usr/sbin")
+ import setns
+
+ (cgroup_fn, pid) = get_sliver_process(slice_name, "/sbin/init")
+ if (not cgroup_fn) or (not pid):
+ return None
+
+ path = '/proc/%s/ns/net'%pid
+
+ result = None
+ try:
+ setns.chcontext(path)
+
+ args = ["/sbin/ifconfig", device]
+ sub = subprocess.Popen(args, stderr = subprocess.PIPE, stdout = subprocess.PIPE)
+ sub.wait()
+
+ if (sub.returncode != 0):
+ logger.log("get_slice_ifconfig: error in ifconfig: %s" % sub.stderr.read())
+
+ result = sub.stdout.read()
+ finally:
+ setns.chcontext("/proc/1/ns/net")
+
+ return result
+
+def get_sliver_ip(slice_name):
+ ifconfig = get_sliver_ifconfig(slice_name)
+ if not ifconfig:
+ return None
+
+ for line in ifconfig.split("\n"):
+ if "inet addr:" in line:
+ # example: ' inet addr:192.168.122.189 Bcast:192.168.122.255 Mask:255.255.255.0'
+ parts = line.strip().split()
+ if len(parts)>=2 and parts[1].startswith("addr:"):
+ return parts[1].split(":")[1]
+
+ return None
+
+### this returns the kind of virtualization on the node
+# either 'vs' or 'lxc'
+# also caches it in /etc/planetlab/virt for next calls
+# could be promoted to core nm if need be
+virt_stamp="/etc/planetlab/virt"
+def get_node_virt ():
+ try:
+ return file(virt_stamp).read().strip()
+ except:
+ pass
+ logger.log("Computing virt..")
+ try:
+ if subprocess.call ([ 'vserver', '--help' ]) ==0: virt='vs'
+ else: virt='lxc'
+ except:
+ virt='lxc'
+ with file(virt_stamp,"w") as f:
+ f.write(virt)
+ return virt
+
+def command_in_slice (slicename, argv):
+ # with vserver this can be done using vserver .. exec <trigger-script>
+ # with lxc this is less clear as we are still discussing how lxcsu should behave
+ # ideally we'd need to run lxcsu .. <trigger-script>
+ virt=get_node_virt()
+ if virt=='vs':
+ return [ 'vserver', slicename, 'exec', ] + argv
+ elif virt=='lxc':
+ return [ 'lxcsu', slicename, ] + argv
+ logger.log("command_in_slice: WARNING: could not find a valid virt")
+ return argv
+