import os
+import sys
import time
import subprocess
import re
import fcntl
import resource
import logging
+import logging.handlers
import signal
+import OpenSSL
+import datetime
+import calendar
+import hmac
+import collections
+import struct
+import IN
from cStringIO import StringIO
try:
- from hashlib import sha1
+ import ctypes
except ImportError:
- import sha
- sha1 = sha.new
+ ctypes = None
from ganeti import errors
from ganeti import constants
+from ganeti import compat
_locksheld = []
_RANDOM_UUID_FILE = "/proc/sys/kernel/random/uuid"
+HEX_CHAR_RE = r"[a-zA-Z0-9]"
+VALID_X509_SIGNATURE_SALT = re.compile("^%s+$" % HEX_CHAR_RE, re.S)
+X509_SIGNATURE = re.compile(r"^%s:\s*(?P<salt>%s+)/(?P<sign>%s+)$" %
+ (re.escape(constants.X509_CERT_SIGNATURE_HEADER),
+ HEX_CHAR_RE, HEX_CHAR_RE),
+ re.S | re.I)
+
+# 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)
+
+# Certificate verification results
+(CERT_WARNING,
+ CERT_ERROR) = range(1, 3)
+
+# Flags for mlockall() (from bits/mman.h)
+_MCL_CURRENT = 1
+_MCL_FUTURE = 2
+
class RunResult(object):
"""Holds the result of running external programs.
output = property(_GetOutput, None, None, "Return full output")
-def RunCmd(cmd, env=None, output=None, cwd='/'):
+def _BuildCmdEnvironment(env, reset):
+ """Builds the environment for an external program.
+
+ """
+ if reset:
+ cmd_env = {}
+ else:
+ cmd_env = os.environ.copy()
+ cmd_env["LC_ALL"] = "C"
+
+ if env is not None:
+ cmd_env.update(env)
+
+ return cmd_env
+
+
+def RunCmd(cmd, env=None, output=None, cwd="/", reset_env=False):
"""Execute a (shell) command.
The command should not read from its standard input, as it will be
closed.
- @type cmd: string or list
+ @type cmd: string or list
@param cmd: Command to run
@type env: dict
- @param env: Additional environment
+ @param env: Additional environment variables
@type output: str
@param output: if desired, the output of the command can be
saved in a file instead of the RunResult instance; this
@type cwd: string
@param cwd: if specified, will be used as the working
directory for the command; the default will be /
+ @type reset_env: boolean
+ @param reset_env: whether to reset or keep the default os environment
@rtype: L{RunResult}
@return: RunResult instance
@raise errors.ProgrammerError: if we call this when forks are disabled
if no_fork:
raise errors.ProgrammerError("utils.RunCmd() called with fork() disabled")
- if isinstance(cmd, list):
+ if isinstance(cmd, basestring):
+ strcmd = cmd
+ shell = True
+ else:
cmd = [str(val) for val in cmd]
- strcmd = " ".join(cmd)
+ strcmd = ShellQuoteArgs(cmd)
shell = False
+
+ if output:
+ logging.debug("RunCmd %s, output file '%s'", strcmd, output)
else:
- strcmd = cmd
- shell = True
- logging.debug("RunCmd '%s'", strcmd)
+ logging.debug("RunCmd %s", strcmd)
- cmd_env = os.environ.copy()
- cmd_env["LC_ALL"] = "C"
- if env is not None:
- cmd_env.update(env)
+ cmd_env = _BuildCmdEnvironment(env, reset_env)
try:
if output is None:
return RunResult(exitcode, signal_, out, err, strcmd)
+def StartDaemon(cmd, env=None, cwd="/", output=None, output_fd=None,
+ pidfile=None):
+ """Start a daemon process after forking twice.
+
+ @type cmd: string or list
+ @param cmd: Command to run
+ @type env: dict
+ @param env: Additional environment variables
+ @type cwd: string
+ @param cwd: Working directory for the program
+ @type output: string
+ @param output: Path to file in which to save the output
+ @type output_fd: int
+ @param output_fd: File descriptor for output
+ @type pidfile: string
+ @param pidfile: Process ID file
+ @rtype: int
+ @return: Daemon process ID
+ @raise errors.ProgrammerError: if we call this when forks are disabled
+
+ """
+ if no_fork:
+ raise errors.ProgrammerError("utils.StartDaemon() called with fork()"
+ " disabled")
+
+ if output and not (bool(output) ^ (output_fd is not None)):
+ raise errors.ProgrammerError("Only one of 'output' and 'output_fd' can be"
+ " specified")
+
+ if isinstance(cmd, basestring):
+ cmd = ["/bin/sh", "-c", cmd]
+
+ strcmd = ShellQuoteArgs(cmd)
+
+ if output:
+ logging.debug("StartDaemon %s, output file '%s'", strcmd, output)
+ else:
+ logging.debug("StartDaemon %s", strcmd)
+
+ cmd_env = _BuildCmdEnvironment(env, False)
+
+ # Create pipe for sending PID back
+ (pidpipe_read, pidpipe_write) = os.pipe()
+ try:
+ try:
+ # Create pipe for sending error messages
+ (errpipe_read, errpipe_write) = os.pipe()
+ try:
+ try:
+ # First fork
+ pid = os.fork()
+ if pid == 0:
+ try:
+ # Child process, won't return
+ _StartDaemonChild(errpipe_read, errpipe_write,
+ pidpipe_read, pidpipe_write,
+ cmd, cmd_env, cwd,
+ output, output_fd, pidfile)
+ finally:
+ # Well, maybe child process failed
+ os._exit(1) # pylint: disable-msg=W0212
+ finally:
+ _CloseFDNoErr(errpipe_write)
+
+ # Wait for daemon to be started (or an error message to arrive) and read
+ # up to 100 KB as an error message
+ errormsg = RetryOnSignal(os.read, errpipe_read, 100 * 1024)
+ finally:
+ _CloseFDNoErr(errpipe_read)
+ finally:
+ _CloseFDNoErr(pidpipe_write)
+
+ # Read up to 128 bytes for PID
+ pidtext = RetryOnSignal(os.read, pidpipe_read, 128)
+ finally:
+ _CloseFDNoErr(pidpipe_read)
+
+ # Try to avoid zombies by waiting for child process
+ try:
+ os.waitpid(pid, 0)
+ except OSError:
+ pass
+
+ if errormsg:
+ raise errors.OpExecError("Error when starting daemon process: %r" %
+ errormsg)
+
+ try:
+ return int(pidtext)
+ except (ValueError, TypeError), err:
+ raise errors.OpExecError("Error while trying to parse PID %r: %s" %
+ (pidtext, err))
+
+
+def _StartDaemonChild(errpipe_read, errpipe_write,
+ pidpipe_read, pidpipe_write,
+ args, env, cwd,
+ output, fd_output, pidfile):
+ """Child process for starting daemon.
+
+ """
+ try:
+ # Close parent's side
+ _CloseFDNoErr(errpipe_read)
+ _CloseFDNoErr(pidpipe_read)
+
+ # First child process
+ os.chdir("/")
+ os.umask(077)
+ os.setsid()
+
+ # And fork for the second time
+ pid = os.fork()
+ if pid != 0:
+ # Exit first child process
+ os._exit(0) # pylint: disable-msg=W0212
+
+ # Make sure pipe is closed on execv* (and thereby notifies original process)
+ SetCloseOnExecFlag(errpipe_write, True)
+
+ # List of file descriptors to be left open
+ noclose_fds = [errpipe_write]
+
+ # Open PID file
+ if pidfile:
+ try:
+ # TODO: Atomic replace with another locked file instead of writing into
+ # it after creating
+ fd_pidfile = os.open(pidfile, os.O_WRONLY | os.O_CREAT, 0600)
+
+ # Lock the PID file (and fail if not possible to do so). Any code
+ # wanting to send a signal to the daemon should try to lock the PID
+ # file before reading it. If acquiring the lock succeeds, the daemon is
+ # no longer running and the signal should not be sent.
+ LockFile(fd_pidfile)
+
+ os.write(fd_pidfile, "%d\n" % os.getpid())
+ except Exception, err:
+ raise Exception("Creating and locking PID file failed: %s" % err)
+
+ # Keeping the file open to hold the lock
+ noclose_fds.append(fd_pidfile)
+
+ SetCloseOnExecFlag(fd_pidfile, False)
+ else:
+ fd_pidfile = None
+
+ # Open /dev/null
+ fd_devnull = os.open(os.devnull, os.O_RDWR)
+
+ assert not output or (bool(output) ^ (fd_output is not None))
+
+ if fd_output is not None:
+ pass
+ elif output:
+ # Open output file
+ try:
+ # TODO: Implement flag to set append=yes/no
+ fd_output = os.open(output, os.O_WRONLY | os.O_CREAT, 0600)
+ except EnvironmentError, err:
+ raise Exception("Opening output file failed: %s" % err)
+ else:
+ fd_output = fd_devnull
+
+ # Redirect standard I/O
+ os.dup2(fd_devnull, 0)
+ os.dup2(fd_output, 1)
+ os.dup2(fd_output, 2)
+
+ # Send daemon PID to parent
+ RetryOnSignal(os.write, pidpipe_write, str(os.getpid()))
+
+ # Close all file descriptors except stdio and error message pipe
+ CloseFDs(noclose_fds=noclose_fds)
+
+ # Change working directory
+ os.chdir(cwd)
+
+ if env is None:
+ os.execvp(args[0], args)
+ else:
+ os.execvpe(args[0], args, env)
+ except: # pylint: disable-msg=W0702
+ try:
+ # Report errors to original process
+ buf = str(sys.exc_info()[1])
+
+ RetryOnSignal(os.write, errpipe_write, buf)
+ except: # pylint: disable-msg=W0702
+ # Ignore errors in error handling
+ pass
+
+ os._exit(1) # pylint: disable-msg=W0212
+
+
def _RunCmdPipe(cmd, env, via_shell, cwd):
"""Run a command and return its output.
child.stderr.fileno(): (err, child.stderr),
}
for fd in fdmap:
- status = fcntl.fcntl(fd, fcntl.F_GETFL)
- fcntl.fcntl(fd, fcntl.F_SETFL, status | os.O_NONBLOCK)
+ SetNonblockFlag(fd, True)
while fdmap:
- try:
- pollresult = poller.poll()
- except EnvironmentError, eerr:
- if eerr.errno == errno.EINTR:
- continue
- raise
- except select.error, serr:
- if serr[0] == errno.EINTR:
- continue
- raise
+ pollresult = RetryOnSignal(poller.poll)
for fd, event in pollresult:
if event & select.POLLIN or event & select.POLLPRI:
return status
+def SetCloseOnExecFlag(fd, enable):
+ """Sets or unsets the close-on-exec flag on a file descriptor.
+
+ @type fd: int
+ @param fd: File descriptor
+ @type enable: bool
+ @param enable: Whether to set or unset it.
+
+ """
+ flags = fcntl.fcntl(fd, fcntl.F_GETFD)
+
+ if enable:
+ flags |= fcntl.FD_CLOEXEC
+ else:
+ flags &= ~fcntl.FD_CLOEXEC
+
+ fcntl.fcntl(fd, fcntl.F_SETFD, flags)
+
+
+def SetNonblockFlag(fd, enable):
+ """Sets or unsets the O_NONBLOCK flag on on a file descriptor.
+
+ @type fd: int
+ @param fd: File descriptor
+ @type enable: bool
+ @param enable: Whether to set or unset it
+
+ """
+ flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+
+ if enable:
+ flags |= os.O_NONBLOCK
+ else:
+ flags &= ~os.O_NONBLOCK
+
+ fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+
+
+def RetryOnSignal(fn, *args, **kwargs):
+ """Calls a function again if it failed due to EINTR.
+
+ """
+ while True:
+ 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 RunParts(dir_name, env=None, reset_env=False):
+ """Run Scripts or programs in a directory
+
+ @type dir_name: string
+ @param dir_name: absolute path to a directory
+ @type env: dict
+ @param env: The environment to use
+ @type reset_env: boolean
+ @param reset_env: whether to reset or keep the default os environment
+ @rtype: list of tuples
+ @return: list of (name, (one of RUNDIR_STATUS), RunResult)
+
+ """
+ rr = []
+
+ try:
+ dir_contents = ListVisibleFiles(dir_name)
+ except OSError, err:
+ logging.warning("RunParts: skipping %s (cannot list: %s)", dir_name, err)
+ return rr
+
+ for relname in sorted(dir_contents):
+ fname = PathJoin(dir_name, relname)
+ if not (os.path.isfile(fname) and os.access(fname, os.X_OK) and
+ constants.EXT_PLUGIN_MASK.match(relname) is not None):
+ rr.append((relname, constants.RUNPARTS_SKIP, None))
+ else:
+ try:
+ result = RunCmd([fname], env=env, reset_env=reset_env)
+ except Exception, err: # pylint: disable-msg=W0703
+ rr.append((relname, constants.RUNPARTS_ERR, str(err)))
+ else:
+ rr.append((relname, constants.RUNPARTS_RUN, result))
+
+ 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.
raise
+def RemoveDir(dirname):
+ """Remove an empty directory.
+
+ Remove a directory, ignoring non-existing ones.
+ Other errors are passed. This includes the case,
+ where the directory is not empty, so it can't be removed.
+
+ @type dirname: str
+ @param dirname: the empty directory to be removed
+
+ """
+ try:
+ os.rmdir(dirname)
+ except OSError, err:
+ if err.errno != errno.ENOENT:
+ raise
+
+
def RenameFile(old, new, mkdir=False, mkdir_mode=0750):
"""Renames a file.
# 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.
+
+ This function should be called after C{os.fork} in the child process to
+ ensure it creates a newly seeded random generator. Otherwise it would
+ generate the same random parts as the parent process. If several processes
+ race for the creation of a temporary file, this could lead to one not getting
+ a temporary name.
+
+ """
+ # pylint: disable-msg=W0212
+ if hasattr(tempfile, "_once_lock") and hasattr(tempfile, "_name_sequence"):
+ tempfile._once_lock.acquire()
+ try:
+ # Reset random name generator
+ tempfile._name_sequence = None
+ finally:
+ tempfile._once_lock.release()
+ else:
+ logging.critical("The tempfile module misses at least one of the"
+ " '_once_lock' and '_name_sequence' attributes")
+
+
def _FingerprintFile(filename):
"""Compute the fingerprint of a file.
f = open(filename)
- fp = sha1()
+ fp = compat.sha1_hash()
while True:
data = f.read(4096)
if not data:
@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")
try:
pid = int(raw_data)
- except ValueError, err:
+ except (TypeError, ValueError), err:
logging.info("Can't parse pid file contents", exc_info=True)
return 0
return pid
+def ReadLockedPidFile(path):
+ """Reads a locked PID file.
+
+ This can be used together with L{StartDaemon}.
+
+ @type path: string
+ @param path: Path to PID file
+ @return: PID as integer or, if file was unlocked or couldn't be opened, None
+
+ """
+ try:
+ fd = os.open(path, os.O_RDONLY)
+ except EnvironmentError, err:
+ if err.errno == errno.ENOENT:
+ # PID file doesn't exist
+ return None
+ raise
+
+ try:
+ try:
+ # Try to acquire lock
+ LockFile(fd)
+ except errors.LockError:
+ # Couldn't lock, daemon is running
+ return int(os.read(fd, 100))
+ finally:
+ os.close(fd)
+
+ return None
+
+
def MatchNameComponent(key, name_list, case_sensitive=True):
"""Try to match a name against a list.
"""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
-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
+ """
+ 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 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):
return [i for i in seq if i not in seen and not seen.add(i)]
-def IsValidMac(mac):
- """Predicate to check if a MAC address is valid.
+def NormalizeAndValidateMac(mac):
+ """Normalizes and check if a MAC address is valid.
Checks whether the supplied MAC address is formally correct, only
- accepts colon separated format.
+ accepts colon separated format. Normalize it to all lower.
@type mac: str
@param mac: the MAC to be validated
- @rtype: boolean
- @return: True is the MAC seems valid
+ @rtype: str
+ @return: returns the normalized and validated MAC.
+
+ @raise errors.OpPrereqError: If the MAC isn't valid
"""
- mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
- return mac_check.match(mac) is not None
+ mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$", re.I)
+ if not mac_check.match(mac):
+ raise errors.OpPrereqError("Invalid MAC address specified: %s" %
+ mac, errors.ECODE_INVAL)
+
+ return mac.lower()
def TestDelay(duration):
_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.
daemon name
"""
- return os.path.join(constants.RUN_GANETI_DIR, "%s.pid" % name)
+ return PathJoin(constants.RUN_GANETI_DIR, "%s.pid" % name)
+
+
+def EnsureDaemon(name):
+ """Check for and start daemon if not alive.
+
+ """
+ result = RunCmd([constants.DAEMON_UTIL, "check-and-start", name])
+ if result.failed:
+ logging.error("Can't start daemon '%s', failure %s, output: %s",
+ name, result.fail_reason, result.output)
+ return False
+
+ return True
def WritePidFile(name):
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
-def SetupLogging(logfile, debug=False, stderr_logging=False, program="",
- multithreaded=False):
+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,
+ console_logging=False):
"""Configures the logging module.
@type logfile: str
@param logfile: the filename to which we should log
- @type debug: boolean
- @param debug: whether to enable debug messages too or
+ @type debug: integer
+ @param debug: if greater than zero, enable debug messages, otherwise
only those at C{INFO} and above level
@type stderr_logging: boolean
@param stderr_logging: whether we should also log to the standard error
@param program: the name under which we should log messages
@type multithreaded: boolean
@param multithreaded: if True, will add the thread name to the log file
+ @type syslog: string
+ @param syslog: one of 'no', 'yes', 'only':
+ - 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
- stderr logging is disabled
+ syslog/stderr logging is disabled
"""
fmt = "%(asctime)s: " + program + " pid=%(process)d"
+ sft = program + "[%(process)d]:"
if multithreaded:
fmt += "/%(threadName)s"
+ sft += " (%(threadName)s)"
if debug:
fmt += " %(module)s:%(lineno)s"
+ # no debug info for syslog loggers
fmt += " %(levelname)s %(message)s"
+ # yes, we do want the textual level, as remote syslog will probably
+ # lose the error level, and it's easier to grep for it
+ sft += " %(levelname)s %(message)s"
formatter = logging.Formatter(fmt)
+ sys_fmt = logging.Formatter(sft)
root_logger = logging.getLogger("")
root_logger.setLevel(logging.NOTSET)
stderr_handler.setLevel(logging.CRITICAL)
root_logger.addHandler(stderr_handler)
- # this can fail, if the logging directories are not setup or we have
- # a permisssion problem; in this case, it's best to log but ignore
- # 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)
- logfile_handler.setFormatter(formatter)
- if debug:
- logfile_handler.setLevel(logging.DEBUG)
- else:
- logfile_handler.setLevel(logging.INFO)
- root_logger.addHandler(logfile_handler)
- except EnvironmentError:
- if stderr_logging:
- logging.exception("Failed to enable logging to file '%s'", logfile)
- else:
- # we need to re-raise the exception
- raise
+ if syslog in (constants.SYSLOG_YES, constants.SYSLOG_ONLY):
+ facility = logging.handlers.SysLogHandler.LOG_DAEMON
+ syslog_handler = logging.handlers.SysLogHandler(constants.SYSLOG_SOCKET,
+ facility)
+ syslog_handler.setFormatter(sys_fmt)
+ # Never enable debug over syslog
+ syslog_handler.setLevel(logging.INFO)
+ root_logger.addHandler(syslog_handler)
+
+ if syslog != constants.SYSLOG_ONLY:
+ # this can fail, if the logging directories are not setup or we have
+ # a permisssion problem; in this case, it's best to log but ignore
+ # 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:
+ if console_logging:
+ logfile_handler = LogFileHandler(logfile)
+ else:
+ logfile_handler = logging.FileHandler(logfile)
+ logfile_handler.setFormatter(formatter)
+ if debug:
+ logfile_handler.setLevel(logging.DEBUG)
+ else:
+ logfile_handler.setLevel(logging.INFO)
+ root_logger.addHandler(logfile_handler)
+ except EnvironmentError:
+ if stderr_logging or syslog == constants.SYSLOG_YES:
+ logging.exception("Failed to enable logging to file '%s'", logfile)
+ else:
+ # we need to re-raise the exception
+ raise
def IsNormAbsPath(path):
return os.path.normpath(path) == path and os.path.isabs(path)
+def PathJoin(*args):
+ """Safe-join a list of path components.
+
+ Requirements:
+ - the first argument must be an absolute path
+ - no component in the path must have backtracking (e.g. /../),
+ since we check for normalization at the end
+
+ @param args: the path components to be joined
+ @raise ValueError: for invalid paths
+
+ """
+ # ensure we're having at least one path passed in
+ assert args
+ # ensure the first component is an absolute and normalized path name
+ root = args[0]
+ if not IsNormAbsPath(root):
+ raise ValueError("Invalid parameter to PathJoin: '%s'" % str(args[0]))
+ result = os.path.join(*args)
+ # ensure that the whole path is normalized
+ if not IsNormAbsPath(result):
+ raise ValueError("Invalid parameters to PathJoin: '%s'" % str(args))
+ # check that we're still under the original prefix
+ prefix = os.path.commonprefix([root, result])
+ if prefix != root:
+ raise ValueError("Error: path joining resulted in different prefix"
+ " (%s != %s)" % (prefix, root))
+ return result
+
+
def TailFile(fname, lines=20):
"""Return the last lines from a file.
return rows[-lines:]
+def FormatTimestampWithTZ(secs):
+ """Formats a Unix timestamp with the local timezone.
+
+ """
+ return time.strftime("%F %T %Z", time.gmtime(secs))
+
+
+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 _VerifyCertificateInner(expired, not_before, not_after, now,
+ warn_days, error_days):
+ """Verifies certificate validity.
+
+ @type expired: bool
+ @param expired: Whether pyOpenSSL considers the certificate as expired
+ @type not_before: number or None
+ @param not_before: Unix timestamp before which certificate is not valid
+ @type not_after: number or None
+ @param not_after: Unix timestamp after which certificate is invalid
+ @type now: number
+ @param now: Current time as Unix timestamp
+ @type warn_days: number or None
+ @param warn_days: How many days before expiration a warning should be reported
+ @type error_days: number or None
+ @param error_days: How many days before expiration an error should be reported
+
+ """
+ if expired:
+ msg = "Certificate is expired"
+
+ if not_before is not None and not_after is not None:
+ msg += (" (valid from %s to %s)" %
+ (FormatTimestampWithTZ(not_before),
+ FormatTimestampWithTZ(not_after)))
+ elif not_before is not None:
+ msg += " (valid from %s)" % FormatTimestampWithTZ(not_before)
+ elif not_after is not None:
+ msg += " (valid until %s)" % FormatTimestampWithTZ(not_after)
+
+ return (CERT_ERROR, msg)
+
+ elif not_before is not None and not_before > now:
+ return (CERT_WARNING,
+ "Certificate not yet valid (valid from %s)" %
+ FormatTimestampWithTZ(not_before))
+
+ elif not_after is not None:
+ remaining_days = int((not_after - now) / (24 * 3600))
+
+ msg = "Certificate expires in about %d days" % remaining_days
+
+ if error_days is not None and remaining_days <= error_days:
+ return (CERT_ERROR, msg)
+
+ if warn_days is not None and remaining_days <= warn_days:
+ return (CERT_WARNING, msg)
+
+ return (None, None)
+
+
+def VerifyX509Certificate(cert, warn_days, error_days):
+ """Verifies a certificate for LUVerifyCluster.
+
+ @type cert: OpenSSL.crypto.X509
+ @param cert: X509 certificate object
+ @type warn_days: number or None
+ @param warn_days: How many days before expiration a warning should be reported
+ @type error_days: number or None
+ @param error_days: How many days before expiration an error should be reported
+
+ """
+ # Depending on the pyOpenSSL version, this can just return (None, None)
+ (not_before, not_after) = GetX509CertValidity(cert)
+
+ return _VerifyCertificateInner(cert.has_expired(), not_before, not_after,
+ time.time(), warn_days, error_days)
+
+
+def SignX509Certificate(cert, key, salt):
+ """Sign a X509 certificate.
+
+ An RFC822-like signature header is added in front of the certificate.
+
+ @type cert: OpenSSL.crypto.X509
+ @param cert: X509 certificate object
+ @type key: string
+ @param key: Key for HMAC
+ @type salt: string
+ @param salt: Salt for HMAC
+ @rtype: string
+ @return: Serialized and signed certificate in PEM format
+
+ """
+ if not VALID_X509_SIGNATURE_SALT.match(salt):
+ raise errors.GenericError("Invalid salt: %r" % salt)
+
+ # Dumping as PEM here ensures the certificate is in a sane format
+ cert_pem = OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)
+
+ return ("%s: %s/%s\n\n%s" %
+ (constants.X509_CERT_SIGNATURE_HEADER, salt,
+ Sha1Hmac(key, cert_pem, salt=salt),
+ cert_pem))
+
+
+def _ExtractX509CertificateSignature(cert_pem):
+ """Helper function to extract signature from X509 certificate.
+
+ """
+ # Extract signature from original PEM data
+ for line in cert_pem.splitlines():
+ if line.startswith("---"):
+ break
+
+ m = X509_SIGNATURE.match(line.strip())
+ if m:
+ return (m.group("salt"), m.group("sign"))
+
+ raise errors.GenericError("X509 certificate signature is missing")
+
+
+def LoadSignedX509Certificate(cert_pem, key):
+ """Verifies a signed X509 certificate.
+
+ @type cert_pem: string
+ @param cert_pem: Certificate in PEM format and with signature header
+ @type key: string
+ @param key: Key for HMAC
+ @rtype: tuple; (OpenSSL.crypto.X509, string)
+ @return: X509 certificate object and salt
+
+ """
+ (salt, signature) = _ExtractX509CertificateSignature(cert_pem)
+
+ # Load certificate
+ cert = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, cert_pem)
+
+ # Dump again to ensure it's in a sane format
+ sane_pem = OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)
+
+ if not VerifySha1Hmac(key, sane_pem, signature, salt=salt):
+ raise errors.GenericError("X509 certificate signature is invalid")
+
+ return (cert, salt)
+
+
+def Sha1Hmac(key, text, salt=None):
+ """Calculates the HMAC-SHA1 digest of a text.
+
+ HMAC is defined in RFC2104.
+
+ @type key: string
+ @param key: Secret key
+ @type text: string
+
+ """
+ if salt:
+ salted_text = salt + text
+ else:
+ salted_text = text
+
+ return hmac.new(key, salted_text, compat.sha1).hexdigest()
+
+
+def VerifySha1Hmac(key, text, digest, salt=None):
+ """Verifies the HMAC-SHA1 digest of a text.
+
+ HMAC is defined in RFC2104.
+
+ @type key: string
+ @param key: Secret key
+ @type text: string
+ @type digest: string
+ @param digest: Expected digest
+ @rtype: bool
+ @return: Whether HMAC-SHA1 digest matches
+
+ """
+ return digest.lower() == Sha1Hmac(key, text, salt=salt).lower()
+
+
def SafeEncode(text):
"""Return a 'safe' version of a source string.
return resu
+def UnescapeAndSplit(text, sep=","):
+ """Split and unescape a string based on a given separator.
+
+ This function splits a string based on a separator where the
+ separator itself can be escape in order to be an element of the
+ elements. The escaping rules are (assuming coma being the
+ separator):
+ - a plain , separates the elements
+ - a sequence \\\\, (double backslash plus comma) is handled as a
+ backslash plus a separator comma
+ - a sequence \, (backslash plus comma) is handled as a
+ non-separator comma
+
+ @type text: string
+ @param text: the string to split
+ @type sep: string
+ @param text: the separator
+ @rtype: string
+ @return: a list of strings
+
+ """
+ # we split the list by sep (with no escaping at this stage)
+ slist = text.split(sep)
+ # next, we revisit the elements and if any of them ended with an odd
+ # number of backslashes, then we join it with the next
+ rlist = []
+ while slist:
+ e1 = slist.pop(0)
+ if e1.endswith("\\"):
+ num_b = len(e1) - len(e1.rstrip("\\"))
+ if num_b % 2 == 1:
+ e2 = slist.pop(0)
+ # here the backslashes remain (all), and will be reduced in
+ # the next step
+ rlist.append(e1 + sep + e2)
+ continue
+ rlist.append(e1)
+ # finally, replace backslash-something with something
+ rlist = [re.sub(r"\\(.)", r"\1", v) for v in rlist]
+ return rlist
+
+
def CommaJoin(names):
"""Nicely join a set of identifiers.
for (curpath, _, files) in os.walk(path):
for filename in files:
- st = os.lstat(os.path.join(curpath, filename))
+ st = os.lstat(PathJoin(curpath, filename))
size += st.st_size
return BytesToMebibyte(size)
return (tsize, fsize)
+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: bool
+ @return: Function's result
+
+ """
+ pid = os.fork()
+ if pid == 0:
+ # Child process
+ try:
+ # In case the function uses temporary files
+ ResetTempfileModule()
+
+ # Call function
+ result = int(bool(fn(*args)))
+ assert result in (0, 1)
+ except: # pylint: disable-msg=W0702
+ logging.exception("Error while calling function in separate process")
+ # 0 and 1 are reserved for the return value
+ result = 33
+
+ os._exit(result) # pylint: disable-msg=W0212
+
+ # Parent process
+
+ # Avoid zombies and check exit code
+ (_, status) = os.waitpid(pid, 0)
+
+ if os.WIFSIGNALED(status):
+ exitcode = None
+ signum = os.WTERMSIG(status)
+ else:
+ exitcode = os.WEXITSTATUS(status)
+ signum = None
+
+ if not (exitcode in (0, 1) and signum is None):
+ raise errors.GenericError("Child program failed (code=%s, signal=%s)" %
+ (exitcode, signum))
+
+ 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.
+
"""
# Update for next run
if self._limit is None or self._next < self._limit:
- self._next = max(self._limit, self._next * self._factor)
+ self._next = min(self._limit, self._next * self._factor)
return current
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
wait_fn(current_delay)
+def GetClosedTempfile(*args, **kwargs):
+ """Creates a temporary file and returns its path.
+
+ """
+ (fd, path) = tempfile.mkstemp(*args, **kwargs)
+ _CloseFDNoErr(fd)
+ return path
+
+
+def GenerateSelfSignedX509Cert(common_name, validity):
+ """Generates a self-signed X509 certificate.
+
+ @type common_name: string
+ @param common_name: commonName value
+ @type validity: int
+ @param validity: Validity for certificate in seconds
+
+ """
+ # Create private and public key
+ key = OpenSSL.crypto.PKey()
+ key.generate_key(OpenSSL.crypto.TYPE_RSA, constants.RSA_KEY_BITS)
+
+ # Create self-signed certificate
+ cert = OpenSSL.crypto.X509()
+ if common_name:
+ cert.get_subject().CN = common_name
+ cert.set_serial_number(1)
+ cert.gmtime_adj_notBefore(0)
+ cert.gmtime_adj_notAfter(validity)
+ cert.set_issuer(cert.get_subject())
+ cert.set_pubkey(key)
+ cert.sign(key, constants.X509_CERT_SIGN_DIGEST)
+
+ key_pem = OpenSSL.crypto.dump_privatekey(OpenSSL.crypto.FILETYPE_PEM, key)
+ cert_pem = OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)
+
+ return (key_pem, cert_pem)
+
+
+def GenerateSelfSignedSslCert(filename, validity=(5 * 365)):
+ """Legacy function to generate self-signed X509 certificate.
+
+ """
+ (key_pem, cert_pem) = GenerateSelfSignedX509Cert(None,
+ validity * 24 * 60 * 60)
+
+ WriteFile(filename, mode=0400, data=key_pem + cert_pem)
+
+
class FileLock(object):
"""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()
"""Close the file and release the lock.
"""
- if self.fd:
+ if hasattr(self, "fd") and self.fd:
self.fd.close()
self.fd = None
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.
return wrap
+class SignalWakeupFd(object):
+ try:
+ # This is only supported in Python 2.5 and above (some distributions
+ # backported it to Python 2.4)
+ _set_wakeup_fd_fn = signal.set_wakeup_fd
+ except AttributeError:
+ # Not supported
+ def _SetWakeupFd(self, _): # pylint: disable-msg=R0201
+ return -1
+ else:
+ def _SetWakeupFd(self, fd):
+ return self._set_wakeup_fd_fn(fd)
+
+ def __init__(self):
+ """Initializes this class.
+
+ """
+ (read_fd, write_fd) = os.pipe()
+
+ # Once these succeeded, the file descriptors will be closed automatically.
+ # Buffer size 0 is important, otherwise .read() with a specified length
+ # might buffer data and the file descriptors won't be marked readable.
+ self._read_fh = os.fdopen(read_fd, "r", 0)
+ self._write_fh = os.fdopen(write_fd, "w", 0)
+
+ self._previous = self._SetWakeupFd(self._write_fh.fileno())
+
+ # Utility functions
+ self.fileno = self._read_fh.fileno
+ self.read = self._read_fh.read
+
+ def Reset(self):
+ """Restores the previous wakeup file descriptor.
+
+ """
+ if hasattr(self, "_previous") and self._previous is not None:
+ self._SetWakeupFd(self._previous)
+ self._previous = None
+
+ def Notify(self):
+ """Notifies the wakeup file descriptor.
+
+ """
+ self._write_fh.write("\0")
+
+ def __del__(self):
+ """Called before object deletion.
+
+ """
+ self.Reset()
+
+
class SignalHandler(object):
"""Generic signal handler class.
@ivar called: tracks whether any of the signals have been raised
"""
- def __init__(self, signum):
+ def __init__(self, signum, handler_fn=None, wakeup=None):
"""Constructs a new SignalHandler instance.
@type signum: int or list of ints
@param signum: Single signal number or set of signal numbers
+ @type handler_fn: callable
+ @param handler_fn: Signal handling function
"""
+ assert handler_fn is None or callable(handler_fn)
+
self.signum = set(signum)
self.called = False
+ self._handler_fn = handler_fn
+ self._wakeup = wakeup
+
self._previous = {}
try:
for signum in self.signum:
# solution in Python -- there are no atomic types.
self.called = True
+ if self._wakeup:
+ # Notify whoever is interested in signals
+ self._wakeup.Notify()
+
+ if self._handler_fn:
+ self._handler_fn(signum, frame)
+
class FieldSet(object):
"""A simple field set.
projects / ganeti-local / blobdiff