+# $Id$
+# $URL$
+
"""A few things that didn't seem to fit anywhere else."""
-import cPickle
-import errno
import os
import pwd
import tempfile
+import fcntl
+import errno
import threading
+import subprocess
import logger
+PID_FILE = '/var/run/nodemanager.pid'
+
+####################
+def get_default_if():
+ interface = get_if_from_hwaddr(get_hwaddr_from_plnode())
+ if not interface: interface = "eth0"
+ return interface
-PID_FILE = '/var/run/nm.pid'
+def get_hwaddr_from_plnode():
+ try:
+ for line in open("/usr/boot/plnode.txt", 'r').readlines():
+ if line.startswith("NET_DEVICE"):
+ return line.split("=")[1].strip().strip('"')
+ except:
+ pass
+ return None
+def get_if_from_hwaddr(hwaddr):
+ import sioc
+ devs = sioc.gifconf()
+ for dev in devs:
+ dev_hwaddr = sioc.gifhwaddr(dev)
+ if dev_hwaddr == hwaddr: return dev
+ return None
+
+####################
+# daemonizing
def as_daemon_thread(run):
"""Call function <run> with no arguments in its own thread."""
thr = threading.Thread(target=run)
os.chdir('/')
os.umask(0)
devnull = os.open(os.devnull, os.O_RDWR)
- for fd in range(3): os.dup2(devnull, fd)
+ os.dup2(devnull, 0)
+ # xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
+ crashlog = os.open('/var/log/nodemanager.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
+ os.dup2(crashlog, 1)
+ os.dup2(crashlog, 2)
def fork_as(su, function, *args):
"""fork(), cd / to avoid keeping unused directories open, close all nonstandard file descriptors (to avoid capturing open sockets), fork() again (to avoid zombies) and call <function> with arguments <args> in the grandchild process. If <su> is not None, set our group and user ids appropriately in the child process."""
try:
os.chdir('/')
close_nonstandard_fds()
- pw_ent = pwd.getpwnam(su)
- os.setegid(pw_ent[3])
- os.seteuid(pw_ent[2])
+ if su:
+ pw_ent = pwd.getpwnam(su)
+ os.setegid(pw_ent[3])
+ os.seteuid(pw_ent[2])
child_pid = os.fork()
if child_pid == 0: function(*args)
except:
os.seteuid(os.getuid()) # undo su so we can write the log file
os.setegid(os.getgid())
- logger.log_exc()
+ logger.log_exc("tools: fork_as")
os._exit(0)
else: os.waitpid(child_pid, 0)
+####################
+# manage files
def pid_file():
- """We use a pid file to ensure that only one copy of NM is running at a given time. If successful, this function will write a pid file containing the pid of the current process. The return value is the pid of the other running process, or None otherwise."""
+ """We use a pid file to ensure that only one copy of NM is running at a given time.
+If successful, this function will write a pid file containing the pid of the current process.
+The return value is the pid of the other running process, or None otherwise."""
other_pid = None
if os.access(PID_FILE, os.F_OK): # check for a pid file
handle = open(PID_FILE) # pid file exists, read it
try: do_write(f)
finally: f.close()
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
+def replace_file_with_string (target, new_contents):
+ try:
+ current=file(target).read()
+ except:
+ current=""
+ # xxx if verbose, report diffs...
+ if current==new_contents:
+ return False
+ # overwrite target file
+ f=file(target,'w')
+ f.write(new_contents)
+ f.close()
+ 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
+
+# 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)