import fcntl
import resource
import logging
+import signal
from cStringIO import StringIO
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
debug = False
+debug_locks = False
no_fork = False
"failed", "fail_reason", "cmd"]
- def __init__(self, exit_code, signal, stdout, stderr, cmd):
+ def __init__(self, exit_code, signal_, stdout, stderr, cmd):
self.cmd = cmd
self.exit_code = exit_code
- self.signal = signal
+ self.signal = signal_
self.stdout = stdout
self.stderr = stderr
- self.failed = (signal is not None or exit_code != 0)
+ self.failed = (signal_ is not None or exit_code != 0)
if self.signal is not None:
self.fail_reason = "terminated by signal %s" % self.signal
output = property(_GetOutput, None, None, "Return full output")
-def RunCmd(cmd):
+def RunCmd(cmd, env=None):
"""Execute a (shell) command.
The command should not read from its standard input, as it will be
closed.
- Args:
- cmd: command to run. (str)
-
- Returns: `RunResult` instance
+ @param cmd: Command to run
+ @type cmd: string or list
+ @param env: Additional environment
+ @type env: dict
+ @return: `RunResult` instance
+ @rtype: RunResult
"""
if no_fork:
strcmd = cmd
shell = True
logging.debug("RunCmd '%s'", strcmd)
- env = os.environ.copy()
- env["LC_ALL"] = "C"
+
+ cmd_env = os.environ.copy()
+ cmd_env["LC_ALL"] = "C"
+ if env is not None:
+ cmd_env.update(env)
+
poller = select.poll()
child = subprocess.Popen(cmd, shell=shell,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE,
stdin=subprocess.PIPE,
- close_fds=True, env=env)
+ close_fds=True, env=cmd_env)
child.stdin.close()
poller.register(child.stdout, select.POLLIN)
status = child.wait()
if status >= 0:
exitcode = status
- signal = None
+ signal_ = None
else:
exitcode = None
- signal = -status
+ signal_ = -status
- return RunResult(exitcode, signal, out, err, strcmd)
+ return RunResult(exitcode, signal_, out, err, strcmd)
def RemoveFile(filename):
Returns: true or false, depending on if the pid exists or not
- Remarks: zombie processes treated as not alive
+ Remarks: zombie processes treated as not alive, and giving a pid <=
+ 0 makes the function to return False.
"""
+ if pid <= 0:
+ return False
+
try:
f = open("/proc/%d/status" % pid)
except IOError, err:
return alive
+def ReadPidFile(pidfile):
+ """Read the pid from a file.
+
+ @param pidfile: Path to a file containing the pid to be checked
+ @type pidfile: string (filename)
+ @return: The process id, if the file exista and contains a valid PID,
+ otherwise 0
+ @rtype: int
+
+ """
+ try:
+ pf = open(pidfile, 'r')
+ except EnvironmentError, err:
+ if err.errno != errno.ENOENT:
+ logging.exception("Can't read pid file?!")
+ return 0
+
+ try:
+ pid = int(pf.read())
+ except ValueError, err:
+ logging.info("Can't parse pid file contents", exc_info=True)
+ return 0
+
+ return pid
+
+
def MatchNameComponent(key, name_list):
"""Try to match a name against a list.
return success
+def OwnIpAddress(address):
+ """Check if the current host has the the given IP address.
+
+ Currently this is done by tcp-pinging the address from the loopback
+ address.
+
+ @type address: string
+ @param address: the addres to check
+ @rtype: bool
+
+ """
+ return TcpPing(address, constants.DEFAULT_NODED_PORT,
+ source=constants.LOCALHOST_IP_ADDRESS)
+
+
def ListVisibleFiles(path):
"""Returns a list of all visible files in a directory.
f.close()
+def GenerateSecret():
+ """Generates a random secret.
+
+ This will generate a pseudo-random secret, and return its sha digest
+ (so that it can be used where an ASCII string is needed).
+
+ """
+ return sha.new(os.urandom(64)).hexdigest()
+
+
+def ReadFile(file_name, size=None):
+ """Reads a file.
+
+ @type size: None or int
+ @param size: Read at most size bytes
+
+ """
+ f = open(file_name, "r")
+ try:
+ if size is None:
+ return f.read()
+ else:
+ return f.read(size)
+ finally:
+ f.close()
+
+
def WriteFile(file_name, fn=None, data=None,
mode=None, uid=-1, gid=-1,
atime=None, mtime=None, close=True,
return 0
+def DaemonPidFileName(name):
+ """Compute a ganeti pid file absolute path, given the daemon name.
+
+ """
+ return os.path.join(constants.RUN_GANETI_DIR, "%s.pid" % name)
+
+
+def WritePidFile(name):
+ """Write the current process pidfile.
+
+ The file will be written to constants.RUN_GANETI_DIR/name.pid
+
+ """
+ pid = os.getpid()
+ pidfilename = DaemonPidFileName(name)
+ if IsProcessAlive(ReadPidFile(pidfilename)):
+ raise errors.GenericError("%s contains a live process" % pidfilename)
+
+ WriteFile(pidfilename, data="%d\n" % pid)
+
+
+def RemovePidFile(name):
+ """Remove the current process pidfile.
+
+ Any errors are ignored.
+
+ """
+ pid = os.getpid()
+ pidfilename = DaemonPidFileName(name)
+ # TODO: we could check here that the file contains our pid
+ try:
+ RemoveFile(pidfilename)
+ except:
+ pass
+
+
+def KillProcess(pid, signal_=signal.SIGTERM, timeout=30):
+ """Kill a process given by its pid.
+
+ @type pid: int
+ @param pid: The PID to terminate.
+ @type signal_: int
+ @param signal_: The signal to send, by default SIGTERM
+ @type timeout: int
+ @param timeout: The timeout after which, if the process is still alive,
+ a SIGKILL will be sent. If not positive, no such checking
+ will be done
+
+ """
+ if pid <= 0:
+ # kill with pid=0 == suicide
+ raise errors.ProgrammerError("Invalid pid given '%s'" % pid)
+
+ if not IsProcessAlive(pid):
+ return
+ os.kill(pid, signal_)
+ if timeout <= 0:
+ return
+ end = time.time() + timeout
+ while time.time() < end and IsProcessAlive(pid):
+ time.sleep(0.1)
+ if IsProcessAlive(pid):
+ os.kill(pid, signal.SIGKILL)
+
+
def FindFile(name, search_path, test=os.path.exists):
"""Look for a filesystem object in a given path.
return None
+def SplitTime(value):
+ """Splits time as floating point number into a tuple.
+
+ @param value: Time in seconds
+ @type value: int or float
+ @return: Tuple containing (seconds, microseconds)
+
+ """
+ (seconds, microseconds) = divmod(int(value * 1000000), 1000000)
+
+ assert 0 <= seconds, \
+ "Seconds must be larger than or equal to 0, but are %s" % seconds
+ assert 0 <= microseconds <= 999999, \
+ "Microseconds must be 0-999999, but are %s" % microseconds
+
+ return (int(seconds), int(microseconds))
+
+
+def MergeTime(timetuple):
+ """Merges a tuple into time as a floating point number.
+
+ @param timetuple: Time as tuple, (seconds, microseconds)
+ @type timetuple: tuple
+ @return: Time as a floating point number expressed in seconds
+
+ """
+ (seconds, microseconds) = timetuple
+
+ assert 0 <= seconds, \
+ "Seconds must be larger than or equal to 0, but are %s" % seconds
+ assert 0 <= microseconds <= 999999, \
+ "Microseconds must be 0-999999, but are %s" % microseconds
+
+ return float(seconds) + (float(microseconds) * 0.000001)
+
+
+def GetNodeDaemonPort():
+ """Get the node daemon port for this cluster.
+
+ Note that this routine does not read a ganeti-specific file, but
+ instead uses socket.getservbyname to allow pre-customization of
+ this parameter outside of Ganeti.
+
+ """
+ try:
+ port = socket.getservbyname("ganeti-noded", "tcp")
+ except socket.error:
+ port = constants.DEFAULT_NODED_PORT
+
+ return port
+
+
+def GetNodeDaemonPassword():
+ """Get the node password for the cluster.
+
+ """
+ return ReadFile(constants.CLUSTER_PASSWORD_FILE)
+
+
def LockedMethod(fn):
"""Synchronized object access decorator.
object's own lock which is hardcoded to '_lock'.
"""
+ def _LockDebug(*args, **kwargs):
+ if debug_locks:
+ logging.debug(*args, **kwargs)
+
def wrapper(self, *args, **kwargs):
assert hasattr(self, '_lock')
lock = self._lock
+ _LockDebug("Waiting for %s", lock)
lock.acquire()
try:
+ _LockDebug("Acquired %s", lock)
result = fn(self, *args, **kwargs)
finally:
+ _LockDebug("Releasing %s", lock)
lock.release()
+ _LockDebug("Released %s", lock)
return result
return wrapper
+
+
+def LockFile(fd):
+ """Locks a file using POSIX locks.
+
+ """
+ try:
+ fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+ except IOError, err:
+ if err.errno == errno.EAGAIN:
+ raise errors.LockError("File already locked")
+ raise
+
+
+class FileLock(object):
+ """Utility class for file locks.
+
+ """
+ def __init__(self, filename):
+ self.filename = filename
+ self.fd = open(self.filename, "w")
+
+ def __del__(self):
+ self.Close()
+
+ def Close(self):
+ if self.fd:
+ self.fd.close()
+ self.fd = None
+
+ def _flock(self, flag, blocking, timeout, errmsg):
+ """Wrapper for fcntl.flock.
+
+ @type flag: int
+ @param flag: Operation flag
+ @type blocking: bool
+ @param blocking: Whether the operation should be done in blocking mode.
+ @type timeout: None or float
+ @param timeout: For how long the operation should be retried (implies
+ non-blocking mode).
+ @type errmsg: string
+ @param errmsg: Error message in case operation fails.
+
+ """
+ assert self.fd, "Lock was closed"
+ assert timeout is None or timeout >= 0, \
+ "If specified, timeout must be positive"
+
+ if timeout is not None:
+ flag |= fcntl.LOCK_NB
+ timeout_end = time.time() + timeout
+
+ # Blocking doesn't have effect with timeout
+ elif not blocking:
+ flag |= fcntl.LOCK_NB
+ timeout_end = None
+
+ retry = True
+ while retry:
+ try:
+ fcntl.flock(self.fd, flag)
+ retry = False
+ except IOError, err:
+ if err.errno in (errno.EAGAIN, ):
+ if timeout_end is not None and time.time() < timeout_end:
+ # Wait before trying again
+ time.sleep(max(0.1, min(1.0, timeout)))
+ else:
+ raise errors.LockError(errmsg)
+ else:
+ logging.exception("fcntl.flock failed")
+ raise
+
+ def Exclusive(self, blocking=False, timeout=None):
+ """Locks the file in exclusive mode.
+
+ """
+ self._flock(fcntl.LOCK_EX, blocking, timeout,
+ "Failed to lock %s in exclusive mode" % self.filename)
+
+ def Shared(self, blocking=False, timeout=None):
+ """Locks the file in shared mode.
+
+ """
+ self._flock(fcntl.LOCK_SH, blocking, timeout,
+ "Failed to lock %s in shared mode" % self.filename)
+
+ def Unlock(self, blocking=True, timeout=None):
+ """Unlocks the file.
+
+ According to "man flock", unlocking can also be a nonblocking operation:
+ "To make a non-blocking request, include LOCK_NB with any of the above
+ operations"
+
+ """
+ self._flock(fcntl.LOCK_UN, blocking, timeout,
+ "Failed to unlock %s" % self.filename)
+
+
+class SignalHandler(object):
+ """Generic signal handler class.
+
+ It automatically restores the original handler when deconstructed or when
+ Reset() is called. You can either pass your own handler function in or query
+ the "called" attribute to detect whether the signal was sent.
+
+ """
+ def __init__(self, signum):
+ """Constructs a new SignalHandler instance.
+
+ @param signum: Single signal number or set of signal numbers
+
+ """
+ if isinstance(signum, (int, long)):
+ self.signum = set([signum])
+ else:
+ self.signum = set(signum)
+
+ self.called = False
+
+ self._previous = {}
+ try:
+ for signum in self.signum:
+ # Setup handler
+ prev_handler = signal.signal(signum, self._HandleSignal)
+ try:
+ self._previous[signum] = prev_handler
+ except:
+ # Restore previous handler
+ signal.signal(signum, prev_handler)
+ raise
+ except:
+ # Reset all handlers
+ self.Reset()
+ # Here we have a race condition: a handler may have already been called,
+ # but there's not much we can do about it at this point.
+ raise
+
+ def __del__(self):
+ self.Reset()
+
+ def Reset(self):
+ """Restore previous handler.
+
+ """
+ for signum, prev_handler in self._previous.items():
+ signal.signal(signum, prev_handler)
+ # If successful, remove from dict
+ del self._previous[signum]
+
+ def Clear(self):
+ """Unsets "called" flag.
+
+ This function can be used in case a signal may arrive several times.
+
+ """
+ self.called = False
+
+ def _HandleSignal(self, signum, frame):
+ """Actual signal handling function.
+
+ """
+ # This is not nice and not absolutely atomic, but it appears to be the only
+ # solution in Python -- there are no atomic types.
+ self.called = True
projects / ganeti-local / blobdiff