import logging
import logging.handlers
import signal
+import datetime
+import calendar
+import collections
+import struct
+import IN
from cStringIO import StringIO
import sha
sha1 = sha.new
+try:
+ import ctypes
+except ImportError:
+ ctypes = None
+
from ganeti import errors
from ganeti import constants
_RANDOM_UUID_FILE = "/proc/sys/kernel/random/uuid"
+# Structure definition for getsockopt(SOL_SOCKET, SO_PEERCRED, ...):
+# struct ucred { pid_t pid; uid_t uid; gid_t gid; };
+#
+# The GNU C Library defines gid_t and uid_t to be "unsigned int" and
+# pid_t to "int".
+#
+# IEEE Std 1003.1-2008:
+# "nlink_t, uid_t, gid_t, and id_t shall be integer types"
+# "blksize_t, pid_t, and ssize_t shall be signed integer types"
+_STRUCT_UCRED = "iII"
+_STRUCT_UCRED_SIZE = struct.calcsize(_STRUCT_UCRED)
+
+# Flags for mlockall() (from bits/mman.h)
+_MCL_CURRENT = 1
+_MCL_FUTURE = 2
+
class RunResult(object):
"""Holds the result of running external programs.
return rr
+def GetSocketCredentials(sock):
+ """Returns the credentials of the foreign process connected to a socket.
+
+ @param sock: Unix socket
+ @rtype: tuple; (number, number, number)
+ @return: The PID, UID and GID of the connected foreign process.
+
+ """
+ peercred = sock.getsockopt(socket.SOL_SOCKET, IN.SO_PEERCRED,
+ _STRUCT_UCRED_SIZE)
+ return struct.unpack(_STRUCT_UCRED, peercred)
+
+
def RemoveFile(filename):
"""Remove a file ignoring some errors.
# as efficient.
if mkdir and err.errno == errno.ENOENT:
# Create directory and try again
- dirname = os.path.dirname(new)
- try:
- os.makedirs(dirname, mode=mkdir_mode)
- except OSError, err:
- # Ignore EEXIST. This is only handled in os.makedirs as included in
- # Python 2.5 and above.
- if err.errno != errno.EEXIST or not os.path.exists(dirname):
- raise
+ Makedirs(os.path.dirname(new), mode=mkdir_mode)
return os.rename(old, new)
raise
+def Makedirs(path, mode=0750):
+ """Super-mkdir; create a leaf directory and all intermediate ones.
+
+ This is a wrapper around C{os.makedirs} adding error handling not implemented
+ before Python 2.5.
+
+ """
+ try:
+ os.makedirs(path, mode)
+ except OSError, err:
+ # Ignore EEXIST. This is only handled in os.makedirs as included in
+ # Python 2.5 and above.
+ if err.errno != errno.EEXIST or not os.path.exists(path):
+ raise
+
+
def ResetTempfileModule():
"""Resets the random name generator of the tempfile module.
@return: True if the process exists
"""
+ def _TryStat(name):
+ try:
+ os.stat(name)
+ return True
+ except EnvironmentError, err:
+ if err.errno in (errno.ENOENT, errno.ENOTDIR):
+ return False
+ elif err.errno == errno.EINVAL:
+ raise RetryAgain(err)
+ raise
+
+ assert isinstance(pid, int), "pid must be an integer"
if pid <= 0:
return False
+ proc_entry = "/proc/%d/status" % pid
+ # /proc in a multiprocessor environment can have strange behaviors.
+ # Retry the os.stat a few times until we get a good result.
try:
- os.stat("/proc/%d/status" % pid)
- return True
- except EnvironmentError, err:
- if err.errno in (errno.ENOENT, errno.ENOTDIR):
- return False
- raise
+ return Retry(_TryStat, (0.01, 1.5, 0.1), 0.5, args=[proc_entry])
+ except RetryTimeout, err:
+ err.RaiseInner()
def ReadPidFile(pidfile):
"""
try:
- raw_data = ReadFile(pidfile)
+ raw_data = ReadOneLineFile(pidfile)
except EnvironmentError, err:
if err.errno != errno.ENOENT:
logging.exception("Can't read pid file")
"""Class implementing resolver and hostname functionality
"""
+ _VALID_NAME_RE = re.compile("^[a-z0-9._-]{1,255}$")
+
def __init__(self, name=None):
"""Initialize the host name object.
return result
+ @classmethod
+ def NormalizeName(cls, hostname):
+ """Validate and normalize the given hostname.
+
+ @attention: the validation is a bit more relaxed than the standards
+ require; most importantly, we allow underscores in names
+ @raise errors.OpPrereqError: when the name is not valid
+
+ """
+ hostname = hostname.lower()
+ if (not cls._VALID_NAME_RE.match(hostname) or
+ # double-dots, meaning empty label
+ ".." in hostname or
+ # empty initial label
+ hostname.startswith(".")):
+ raise errors.OpPrereqError("Invalid hostname '%s'" % hostname,
+ errors.ECODE_INVAL)
+ if hostname.endswith("."):
+ hostname = hostname.rstrip(".")
+ return hostname
+
def GetHostInfo(name=None):
"""Lookup host name and raise an OpPrereqError for failures"""
RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.ShortName())
+def TimestampForFilename():
+ """Returns the current time formatted for filenames.
+
+ The format doesn't contain colons as some shells and applications them as
+ separators.
+
+ """
+ return time.strftime("%Y-%m-%d_%H_%M_%S")
+
+
def CreateBackup(file_name):
"""Creates a backup of a file.
raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" %
file_name)
- prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time()))
+ prefix = ("%s.backup-%s." %
+ (os.path.basename(file_name), TimestampForFilename()))
dir_name = os.path.dirname(file_name)
fsrc = open(file_name, 'rb')
(fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name)
fdst = os.fdopen(fd, 'wb')
try:
+ logging.debug("Backing up %s at %s", file_name, backup_name)
shutil.copyfileobj(fsrc, fdst)
finally:
fdst.close()
@param path: the directory to enumerate
@rtype: list
@return: the list of all files not starting with a dot
+ @raise ProgrammerError: if L{path} is not an absolue and normalized path
"""
+ if not IsNormAbsPath(path):
+ raise errors.ProgrammerError("Path passed to ListVisibleFiles is not"
+ " absolute/normalized: '%s'" % path)
files = [i for i in os.listdir(path) if not i.startswith(".")]
files.sort()
return files
return result
+def ReadOneLineFile(file_name, strict=False):
+ """Return the first non-empty line from a file.
+
+ @type strict: boolean
+ @param strict: if True, abort if the file has more than one
+ non-empty line
+
+ """
+ file_lines = ReadFile(file_name).splitlines()
+ full_lines = filter(bool, file_lines)
+ if not file_lines or not full_lines:
+ raise errors.GenericError("No data in one-liner file %s" % file_name)
+ elif strict and len(full_lines) > 1:
+ raise errors.GenericError("Too many lines in one-liner file %s" %
+ file_name)
+ return full_lines[0]
+
+
def FirstFree(seq, base=0):
"""Returns the first non-existing integer from seq.
return None
-def all(seq, pred=bool): # pylint: disable-msg=W0622
- "Returns True if pred(x) is True for every element in the iterable"
- for _ in itertools.ifilterfalse(pred, seq):
- return False
- return True
+def SingleWaitForFdCondition(fdobj, event, timeout):
+ """Waits for a condition to occur on the socket.
+
+ Immediately returns at the first interruption.
+
+ @type fdobj: integer or object supporting a fileno() method
+ @param fdobj: entity to wait for events on
+ @type event: integer
+ @param event: ORed condition (see select module)
+ @type timeout: float or None
+ @param timeout: Timeout in seconds
+ @rtype: int or None
+ @return: None for timeout, otherwise occured conditions
+
+ """
+ check = (event | select.POLLPRI |
+ select.POLLNVAL | select.POLLHUP | select.POLLERR)
+
+ if timeout is not None:
+ # Poller object expects milliseconds
+ timeout *= 1000
+
+ poller = select.poll()
+ poller.register(fdobj, event)
+ try:
+ # TODO: If the main thread receives a signal and we have no timeout, we
+ # could wait forever. This should check a global "quit" flag or something
+ # every so often.
+ io_events = poller.poll(timeout)
+ except select.error, err:
+ if err[0] != errno.EINTR:
+ raise
+ io_events = []
+ if io_events and io_events[0][1] & check:
+ return io_events[0][1]
+ else:
+ return None
+
+
+class FdConditionWaiterHelper(object):
+ """Retry helper for WaitForFdCondition.
+
+ This class contains the retried and wait functions that make sure
+ WaitForFdCondition can continue waiting until the timeout is actually
+ expired.
+
+ """
+
+ def __init__(self, timeout):
+ self.timeout = timeout
+
+ def Poll(self, fdobj, event):
+ result = SingleWaitForFdCondition(fdobj, event, self.timeout)
+ if result is None:
+ raise RetryAgain()
+ else:
+ return result
+ def UpdateTimeout(self, timeout):
+ self.timeout = timeout
-def any(seq, pred=bool): # pylint: disable-msg=W0622
- "Returns True if pred(x) is True for at least one element in the iterable"
- for _ in itertools.ifilter(pred, seq):
- return True
- return False
+
+def WaitForFdCondition(fdobj, event, timeout):
+ """Waits for a condition to occur on the socket.
+
+ Retries until the timeout is expired, even if interrupted.
+
+ @type fdobj: integer or object supporting a fileno() method
+ @param fdobj: entity to wait for events on
+ @type event: integer
+ @param event: ORed condition (see select module)
+ @type timeout: float or None
+ @param timeout: Timeout in seconds
+ @rtype: int or None
+ @return: None for timeout, otherwise occured conditions
+
+ """
+ if timeout is not None:
+ retrywaiter = FdConditionWaiterHelper(timeout)
+ try:
+ result = Retry(retrywaiter.Poll, RETRY_REMAINING_TIME, timeout,
+ args=(fdobj, event), wait_fn=retrywaiter.UpdateTimeout)
+ except RetryTimeout:
+ result = None
+ else:
+ result = None
+ while result is None:
+ result = SingleWaitForFdCondition(fdobj, event, timeout)
+ return result
def UniqueSequence(seq):
_CloseFDNoErr(fd)
+def Mlockall():
+ """Lock current process' virtual address space into RAM.
+
+ This is equivalent to the C call mlockall(MCL_CURRENT|MCL_FUTURE),
+ see mlock(2) for more details. This function requires ctypes module.
+
+ """
+ if ctypes is None:
+ logging.warning("Cannot set memory lock, ctypes module not found")
+ return
+
+ libc = ctypes.cdll.LoadLibrary("libc.so.6")
+ if libc is None:
+ logging.error("Cannot set memory lock, ctypes cannot load libc")
+ return
+
+ # Some older version of the ctypes module don't have built-in functionality
+ # to access the errno global variable, where function error codes are stored.
+ # By declaring this variable as a pointer to an integer we can then access
+ # its value correctly, should the mlockall call fail, in order to see what
+ # the actual error code was.
+ # pylint: disable-msg=W0212
+ libc.__errno_location.restype = ctypes.POINTER(ctypes.c_int)
+
+ if libc.mlockall(_MCL_CURRENT | _MCL_FUTURE):
+ # pylint: disable-msg=W0212
+ logging.error("Cannot set memory lock: %s",
+ os.strerror(libc.__errno_location().contents.value))
+ return
+
+ logging.debug("Memory lock set")
+
+
def Daemonize(logfile):
"""Daemonize the current process.
return None
for dir_name in search_path:
+ # FIXME: investigate switch to PathJoin
item_name = os.path.sep.join([dir_name, name])
# check the user test and that we're indeed resolving to the given
# basename
return port
+class LogFileHandler(logging.FileHandler):
+ """Log handler that doesn't fallback to stderr.
+
+ When an error occurs while writing on the logfile, logging.FileHandler tries
+ to log on stderr. This doesn't work in ganeti since stderr is redirected to
+ the logfile. This class avoids failures reporting errors to /dev/console.
+
+ """
+ def __init__(self, filename, mode="a", encoding=None):
+ """Open the specified file and use it as the stream for logging.
+
+ Also open /dev/console to report errors while logging.
+
+ """
+ logging.FileHandler.__init__(self, filename, mode, encoding)
+ self.console = open(constants.DEV_CONSOLE, "a")
+
+ def handleError(self, record): # pylint: disable-msg=C0103
+ """Handle errors which occur during an emit() call.
+
+ Try to handle errors with FileHandler method, if it fails write to
+ /dev/console.
+
+ """
+ try:
+ logging.FileHandler.handleError(self, record)
+ except Exception: # pylint: disable-msg=W0703
+ try:
+ self.console.write("Cannot log message:\n%s\n" % self.format(record))
+ except Exception: # pylint: disable-msg=W0703
+ # Log handler tried everything it could, now just give up
+ pass
+
+
def SetupLogging(logfile, debug=0, stderr_logging=False, program="",
- multithreaded=False, syslog=constants.SYSLOG_USAGE):
+ multithreaded=False, syslog=constants.SYSLOG_USAGE,
+ console_logging=False):
"""Configures the logging module.
@type logfile: str
- if no, syslog is not used
- if yes, syslog is used (in addition to file-logging)
- if only, only syslog is used
+ @type console_logging: boolean
+ @param console_logging: if True, will use a FileHandler which falls back to
+ the system console if logging fails
@raise EnvironmentError: if we can't open the log file and
syslog/stderr logging is disabled
# the error if stderr_logging is True, and if false we re-raise the
# exception since otherwise we could run but without any logs at all
try:
- logfile_handler = logging.FileHandler(logfile)
+ if console_logging:
+ logfile_handler = LogFileHandler(logfile)
+ else:
+ logfile_handler = logging.FileHandler(logfile)
logfile_handler.setFormatter(formatter)
if debug:
logfile_handler.setLevel(logging.DEBUG)
return rows[-lines:]
+def _ParseAsn1Generalizedtime(value):
+ """Parses an ASN1 GENERALIZEDTIME timestamp as used by pyOpenSSL.
+
+ @type value: string
+ @param value: ASN1 GENERALIZEDTIME timestamp
+
+ """
+ m = re.match(r"^(\d+)([-+]\d\d)(\d\d)$", value)
+ if m:
+ # We have an offset
+ asn1time = m.group(1)
+ hours = int(m.group(2))
+ minutes = int(m.group(3))
+ utcoffset = (60 * hours) + minutes
+ else:
+ if not value.endswith("Z"):
+ raise ValueError("Missing timezone")
+ asn1time = value[:-1]
+ utcoffset = 0
+
+ parsed = time.strptime(asn1time, "%Y%m%d%H%M%S")
+
+ tt = datetime.datetime(*(parsed[:7])) - datetime.timedelta(minutes=utcoffset)
+
+ return calendar.timegm(tt.utctimetuple())
+
+
+def GetX509CertValidity(cert):
+ """Returns the validity period of the certificate.
+
+ @type cert: OpenSSL.crypto.X509
+ @param cert: X509 certificate object
+
+ """
+ # The get_notBefore and get_notAfter functions are only supported in
+ # pyOpenSSL 0.7 and above.
+ try:
+ get_notbefore_fn = cert.get_notBefore
+ except AttributeError:
+ not_before = None
+ else:
+ not_before_asn1 = get_notbefore_fn()
+
+ if not_before_asn1 is None:
+ not_before = None
+ else:
+ not_before = _ParseAsn1Generalizedtime(not_before_asn1)
+
+ try:
+ get_notafter_fn = cert.get_notAfter
+ except AttributeError:
+ not_after = None
+ else:
+ not_after_asn1 = get_notafter_fn()
+
+ if not_after_asn1 is None:
+ not_after = None
+ else:
+ not_after = _ParseAsn1Generalizedtime(not_after_asn1)
+
+ return (not_before, not_after)
+
+
def SafeEncode(text):
"""Return a 'safe' version of a source string.
return (tsize, fsize)
-def RunInSeparateProcess(fn):
+def RunInSeparateProcess(fn, *args):
"""Runs a function in a separate process.
Note: Only boolean return values are supported.
@type fn: callable
@param fn: Function to be called
- @rtype: tuple of (int/None, int/None)
- @return: Exit code and signal number
+ @rtype: bool
+ @return: Function's result
"""
pid = os.fork()
ResetTempfileModule()
# Call function
- result = int(bool(fn()))
+ result = int(bool(fn(*args)))
assert result in (0, 1)
except: # pylint: disable-msg=W0702
logging.exception("Error while calling function in separate process")
return bool(exitcode)
+def IgnoreSignals(fn, *args, **kwargs):
+ """Tries to call a function ignoring failures due to EINTR.
+
+ """
+ try:
+ return fn(*args, **kwargs)
+ except (EnvironmentError, socket.error), err:
+ if err.errno != errno.EINTR:
+ raise
+ except select.error, err:
+ if not (err.args and err.args[0] == errno.EINTR):
+ raise
+
+
def LockedMethod(fn):
"""Synchronized object access decorator.
class RetryTimeout(Exception):
"""Retry loop timed out.
+ Any arguments which was passed by the retried function to RetryAgain will be
+ preserved in RetryTimeout, if it is raised. If such argument was an exception
+ the RaiseInner helper method will reraise it.
+
"""
+ def RaiseInner(self):
+ if self.args and isinstance(self.args[0], Exception):
+ raise self.args[0]
+ else:
+ raise RetryTimeout(*self.args)
class RetryAgain(Exception):
"""Retry again.
+ Any arguments passed to RetryAgain will be preserved, if a timeout occurs, as
+ arguments to RetryTimeout. If an exception is passed, the RaiseInner() method
+ of the RetryTimeout() method can be used to reraise it.
+
"""
assert calc_delay is None or callable(calc_delay)
while True:
+ retry_args = []
try:
# pylint: disable-msg=W0142
return fn(*args)
- except RetryAgain:
- pass
+ except RetryAgain, err:
+ retry_args = err.args
+ except RetryTimeout:
+ raise errors.ProgrammerError("Nested retry loop detected that didn't"
+ " handle RetryTimeout")
remaining_time = end_time - _time_fn()
if remaining_time < 0.0:
- raise RetryTimeout()
+ # pylint: disable-msg=W0142
+ raise RetryTimeout(*retry_args)
assert remaining_time >= 0.0
"""Utility class for file locks.
"""
- def __init__(self, filename):
+ def __init__(self, fd, filename):
"""Constructor for FileLock.
- This will open the file denoted by the I{filename} argument.
-
+ @type fd: file
+ @param fd: File object
@type filename: str
- @param filename: path to the file to be locked
+ @param filename: Path of the file opened at I{fd}
"""
+ self.fd = fd
self.filename = filename
- self.fd = open(self.filename, "w")
+
+ @classmethod
+ def Open(cls, filename):
+ """Creates and opens a file to be used as a file-based lock.
+
+ @type filename: string
+ @param filename: path to the file to be locked
+
+ """
+ # Using "os.open" is necessary to allow both opening existing file
+ # read/write and creating if not existing. Vanilla "open" will truncate an
+ # existing file -or- allow creating if not existing.
+ return cls(os.fdopen(os.open(filename, os.O_RDWR | os.O_CREAT), "w+"),
+ filename)
def __del__(self):
self.Close()
assert self.fd, "Lock was closed"
assert timeout is None or timeout >= 0, \
"If specified, timeout must be positive"
+ assert not (flag & fcntl.LOCK_NB), "LOCK_NB must not be set"
- if timeout is not None:
+ # When a timeout is used, LOCK_NB must always be set
+ if not (timeout is None and blocking):
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
+ if timeout is None:
+ self._Lock(self.fd, flag, timeout)
+ else:
+ try:
+ Retry(self._Lock, (0.1, 1.2, 1.0), timeout,
+ args=(self.fd, flag, timeout))
+ except RetryTimeout:
+ raise errors.LockError(errmsg)
- # TODO: Convert to utils.Retry
+ @staticmethod
+ def _Lock(fd, flag, timeout):
+ try:
+ fcntl.flock(fd, flag)
+ except IOError, err:
+ if timeout is not None and err.errno == errno.EAGAIN:
+ raise RetryAgain()
- 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
+ logging.exception("fcntl.flock failed")
+ raise
def Exclusive(self, blocking=False, timeout=None):
"""Locks the file in exclusive mode.
"Failed to unlock %s" % self.filename)
+class LineSplitter:
+ """Splits data chunks into lines separated by newline.
+
+ Instances provide a file-like interface.
+
+ """
+ def __init__(self, line_fn, *args):
+ """Initializes this class.
+
+ @type line_fn: callable
+ @param line_fn: Function called for each line, first parameter is line
+ @param args: Extra arguments for L{line_fn}
+
+ """
+ assert callable(line_fn)
+
+ if args:
+ # Python 2.4 doesn't have functools.partial yet
+ self._line_fn = \
+ lambda line: line_fn(line, *args) # pylint: disable-msg=W0142
+ else:
+ self._line_fn = line_fn
+
+ self._lines = collections.deque()
+ self._buffer = ""
+
+ def write(self, data):
+ parts = (self._buffer + data).split("\n")
+ self._buffer = parts.pop()
+ self._lines.extend(parts)
+
+ def flush(self):
+ while self._lines:
+ self._line_fn(self._lines.popleft().rstrip("\r\n"))
+
+ def close(self):
+ self.flush()
+ if self._buffer:
+ self._line_fn(self._buffer)
+
+
def SignalHandled(signums):
"""Signal Handled decoration.
projects / ganeti-local / blobdiff