import errno
import pwd
import itertools
+import select
+import fcntl
+import resource
+
+from cStringIO import StringIO
from ganeti import logger
from ganeti import errors
+from ganeti import constants
_locksheld = []
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
+debug = False
+
class RunResult(object):
"""Simple class for holding the result of running external programs.
else:
self.fail_reason = "unable to determine termination reason"
+ if debug and self.failed:
+ logger.Debug("Command '%s' failed (%s); output: %s" %
+ (self.cmd, self.fail_reason, self.output))
+
def _GetOutput(self):
"""Returns the combined stdout and stderr for easier usage.
def _GetLockFile(subsystem):
"""Compute the file name for a given lock name."""
- return "/var/lock/ganeti_lock_%s" % subsystem
+ return "%s/ganeti_lock_%s" % (constants.LOCK_DIR, subsystem)
-def Lock(name, max_retries=None, debug=False):
+def Lock(name, max_retries=None, debug=False, autoclean=True):
"""Lock a given subsystem.
In case the lock is already held by an alive process, the function
raise errors.LockError('Lock "%s" already held!' % (name,))
errcount = 0
+ cleanupcount = 0
retries = 0
while True:
(lockfile,))
if not IsProcessAlive(pid):
- raise errors.LockError("Stale lockfile %s for pid %d?" %
- (lockfile, pid))
+ if autoclean:
+ cleanupcount += 1
+ if cleanupcount >= 5:
+ raise errors.LockError, ("Too many stale lock cleanups! Check"
+ " what process is dying.")
+ logger.Error('Stale lockfile %s for pid %d, autocleaned.' %
+ (lockfile, pid))
+ RemoveFile(lockfile)
+ continue
+ else:
+ raise errors.LockError("Stale lockfile %s for pid %d?" %
+ (lockfile, pid))
if max_retries and max_retries <= retries:
raise errors.LockError("Can't acquire lock during the specified"
shell = True
env = os.environ.copy()
env["LC_ALL"] = "C"
+ poller = select.poll()
child = subprocess.Popen(cmd, shell=shell,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE,
close_fds=True, env=env)
child.stdin.close()
- out = child.stdout.read()
- err = child.stderr.read()
+ poller.register(child.stdout, select.POLLIN)
+ poller.register(child.stderr, select.POLLIN)
+ out = StringIO()
+ err = StringIO()
+ fdmap = {
+ child.stdout.fileno(): (out, child.stdout),
+ 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)
+
+ while fdmap:
+ for fd, event in poller.poll():
+ if event & select.POLLIN or event & select.POLLPRI:
+ data = fdmap[fd][1].read()
+ # no data from read signifies EOF (the same as POLLHUP)
+ if not data:
+ poller.unregister(fd)
+ del fdmap[fd]
+ continue
+ fdmap[fd][0].write(data)
+ if (event & select.POLLNVAL or event & select.POLLHUP or
+ event & select.POLLERR):
+ poller.unregister(fd)
+ del fdmap[fd]
+
+ out = out.getvalue()
+ err = err.getvalue()
status = child.wait()
if status >= 0:
raise
-def AddEtcHostsEntry(file_name, hostname, ip):
- """Adds an IP address and hostname to /etc/hosts.
+def SetEtcHostsEntry(file_name, ip, hostname, aliases):
+ """Sets the name of an IP address and hostname in /etc/hosts.
"""
- f = open(file_name, 'a+')
+ # Ensure aliases are unique
+ aliases = UniqueSequence([hostname] + aliases)[1:]
+
+ fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
try:
- nl = True
- for line in f:
- fields = line.split()
- if len(fields) < 2 or fields[0].startswith('#'):
- continue
- if fields[0] == ip and hostname in fields[1:]:
- break
- nl = line.endswith('\n')
- else:
- if not nl:
- f.write("\n")
- f.write(ip)
- f.write(' ')
- f.write(hostname)
- f.write("\n")
- f.flush()
- finally:
- f.close()
+ out = os.fdopen(fd, 'w')
+ try:
+ f = open(file_name, 'r')
+ try:
+ written = False
+ for line in f:
+ fields = line.split()
+ if fields and not fields[0].startswith('#') and ip == fields[0]:
+ continue
+ out.write(line)
+
+ out.write("%s\t%s" % (ip, hostname))
+ if aliases:
+ out.write(" %s" % ' '.join(aliases))
+ out.write('\n')
+
+ out.flush()
+ os.fsync(out)
+ os.rename(tmpname, file_name)
+ finally:
+ f.close()
+ finally:
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
def RemoveEtcHostsEntry(file_name, hostname):
"""Removes a hostname from /etc/hosts.
- IP addresses without hostnames are removed from the file.
+ IP addresses without names are removed from the file.
"""
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
try:
while hostname in names:
names.remove(hostname)
if names:
- out.write(fields[0])
- out.write(' ')
- out.write(' '.join(names))
+ out.write("%s %s\n" % (fields[0], ' '.join(names)))
continue
out.write(line)
out.flush()
+ os.fsync(out)
os.rename(tmpname, file_name)
finally:
f.close()
return ' '.join([ShellQuote(i) for i in args])
-
-def TcpPing(source, target, port, timeout=10, live_port_needed=False):
+def TcpPing(target, port, timeout=10, live_port_needed=False, source=None):
"""Simple ping implementation using TCP connect(2).
- Try to do a TCP connect(2) from the specified source IP to the specified
- target IP and the specified target port. If live_port_needed is set to true,
- requires the remote end to accept the connection. The timeout is specified
- in seconds and defaults to 10 seconds
+ Try to do a TCP connect(2) from an optional source IP to the
+ specified target IP and the specified target port. If the optional
+ parameter live_port_needed is set to true, requires the remote end
+ to accept the connection. The timeout is specified in seconds and
+ defaults to 10 seconds. If the source optional argument is not
+ passed, the source address selection is left to the kernel,
+ otherwise we try to connect using the passed address (failures to
+ bind other than EADDRNOTAVAIL will be ignored).
"""
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sucess = False
- try:
- sock.bind((source, 0))
- except socket.error, (errcode, errstring):
- if errcode == errno.EADDRNOTAVAIL:
- success = False
+ if source is not None:
+ try:
+ sock.bind((source, 0))
+ except socket.error, (errcode, errstring):
+ if errcode == errno.EADDRNOTAVAIL:
+ success = False
sock.settimeout(timeout)
"""Returns a list of all visible files in a directory.
"""
- return [i for i in os.listdir(path) if not i.startswith(".")]
+ files = [i for i in os.listdir(path) if not i.startswith(".")]
+ files.sort()
+ return files
def GetHomeDir(user, default=None):
for elem in itertools.ifilter(pred, seq):
return True
return False
+
+
+def UniqueSequence(seq):
+ """Returns a list with unique elements.
+
+ Element order is preserved.
+ """
+ seen = set()
+ 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.
+
+ Checks wether the supplied MAC address is formally correct, only
+ accepts colon separated format.
+ """
+ mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
+ return mac_check.match(mac) is not None
+
+
+def TestDelay(duration):
+ """Sleep for a fixed amount of time.
+
+ """
+ if duration < 0:
+ return False
+ time.sleep(duration)
+ return True
+
+
+def Daemonize(logfile, noclose_fds=None):
+ """Daemonize the current process.
+
+ This detaches the current process from the controlling terminal and
+ runs it in the background as a daemon.
+
+ """
+ UMASK = 077
+ WORKDIR = "/"
+ # Default maximum for the number of available file descriptors.
+ if 'SC_OPEN_MAX' in os.sysconf_names:
+ try:
+ MAXFD = os.sysconf('SC_OPEN_MAX')
+ if MAXFD < 0:
+ MAXFD = 1024
+ except OSError:
+ MAXFD = 1024
+ else:
+ MAXFD = 1024
+
+ # this might fail
+ pid = os.fork()
+ if (pid == 0): # The first child.
+ os.setsid()
+ # this might fail
+ pid = os.fork() # Fork a second child.
+ if (pid == 0): # The second child.
+ os.chdir(WORKDIR)
+ os.umask(UMASK)
+ else:
+ # exit() or _exit()? See below.
+ os._exit(0) # Exit parent (the first child) of the second child.
+ else:
+ os._exit(0) # Exit parent of the first child.
+ maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
+ if (maxfd == resource.RLIM_INFINITY):
+ maxfd = MAXFD
+
+ # Iterate through and close all file descriptors.
+ for fd in range(0, maxfd):
+ if noclose_fds and fd in noclose_fds:
+ continue
+ try:
+ os.close(fd)
+ except OSError: # ERROR, fd wasn't open to begin with (ignored)
+ pass
+ os.open(logfile, os.O_RDWR|os.O_CREAT|os.O_APPEND, 0600)
+ # Duplicate standard input to standard output and standard error.
+ os.dup2(0, 1) # standard output (1)
+ os.dup2(0, 2) # standard error (2)
+ return 0
+
+
+def FindFile(name, search_path, test=os.path.exists):
+ """Look for a filesystem object in a given path.
+
+ This is an abstract method to search for filesystem object (files,
+ dirs) under a given search path.
+
+ Args:
+ - name: the name to look for
+ - search_path: list of directory names
+ - test: the test which the full path must satisfy
+ (defaults to os.path.exists)
+
+ Returns:
+ - full path to the item if found
+ - None otherwise
+
+ """
+ for dir_name in search_path:
+ item_name = os.path.sep.join([dir_name, name])
+ if test(item_name):
+ return item_name
+ return None
projects / ganeti-local / blobdiff