+
+# replace a target file with a new contents - checks for changes
+# 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()
+ except:
+ current=""
+ 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 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: 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
+
+
+####################
+# utilities functions to get (cached) information from the node
+
+# get node_id from /etc/planetlab/node_id and cache it
+_node_id=None
+def node_id():
+ global _node_id
+ if _node_id is None:
+ try:
+ _node_id=int(file("/etc/planetlab/node_id").read())
+ except:
+ _node_id=""
+ return _node_id
+
+_root_context_arch=None
+def root_context_arch():
+ global _root_context_arch
+ if not _root_context_arch:
+ sp=subprocess.Popen(["uname","-i"],stdout=subprocess.PIPE)
+ (_root_context_arch,_)=sp.communicate()
+ _root_context_arch=_root_context_arch.strip()
+ return _root_context_arch
+
+
+####################
+class NMLock:
+ def __init__(self, file):
+ logger.log("tools: Lock %s initialized." % file, 2)
+ self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+ flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+ flags |= fcntl.FD_CLOEXEC
+ fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+ def __del__(self):
+ os.close(self.fd)
+ def acquire(self):
+ logger.log("tools: Lock acquired.", 2)
+ fcntl.lockf(self.fd, fcntl.LOCK_SH)
+ 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
+ """
+
+ # 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
+