"""Ganeti small utilities
+
"""
import shutil
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
+no_fork = 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):
Returns: `RunResult` instance
"""
+ if no_fork:
+ raise errors.ProgrammerError("utils.RunCmd() called with fork() disabled")
+
if isinstance(cmd, list):
cmd = [str(val) for val in cmd]
strcmd = " ".join(cmd)
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:
self.name, self.aliases, self.ipaddrs = self.LookupHostname(name)
self.ip = self.ipaddrs[0]
+ def ShortName(self):
+ """Returns the hostname without domain.
+
+ """
+ return self.name.split('.')[0]
+
@staticmethod
def SysName():
"""Return the current system's name.
return [tup[1] for tup in to_sort]
-def CheckDaemonAlive(pid_file, process_string):
- """Check wether the specified daemon is alive.
-
- Args:
- - pid_file: file to read the daemon pid from, the file is
- expected to contain only a single line containing
- only the PID
- - process_string: a substring that we expect to find in
- the command line of the daemon process
-
- Returns:
- - True if the daemon is judged to be alive (that is:
- - the PID file exists, is readable and contains a number
- - a process of the specified PID is running
- - that process contains the specified string in its
- command line
- - the process is not in state Z (zombie))
- - False otherwise
-
- """
- try:
- pid_file = file(pid_file, 'r')
- try:
- pid = int(pid_file.readline())
- finally:
- pid_file.close()
-
- cmdline_file_path = "/proc/%s/cmdline" % (pid)
- cmdline_file = open(cmdline_file_path, 'r')
- try:
- cmdline = cmdline_file.readline()
- finally:
- cmdline_file.close()
-
- if not process_string in cmdline:
- return False
-
- stat_file_path = "/proc/%s/stat" % (pid)
- stat_file = open(stat_file_path, 'r')
- try:
- process_state = stat_file.readline().split()[2]
- finally:
- stat_file.close()
-
- if process_state == 'Z':
- return False
-
- except (IndexError, IOError, ValueError):
- return False
-
- return True
-
-
def TryConvert(fn, val):
"""Try to convert a value ignoring errors.
key_fields = key.split()
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
- out = os.fdopen(fd, 'w')
try:
- f = open(file_name, 'r')
+ out = os.fdopen(fd, 'w')
try:
- for line in f:
- # Ignore whitespace changes while comparing lines
- if line.split() != key_fields:
+ f = open(file_name, 'r')
+ try:
+ for line in f:
+ # Ignore whitespace changes while comparing lines
+ if line.split() != key_fields:
+ out.write(line)
+
+ out.flush()
+ os.rename(tmpname, file_name)
+ finally:
+ f.close()
+ finally:
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
+
+
+def SetEtcHostsEntry(file_name, ip, hostname, aliases):
+ """Sets the name of an IP address and hostname in /etc/hosts.
+
+ """
+ # Ensure aliases are unique
+ aliases = UniqueSequence([hostname] + aliases)[1:]
+
+ fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
+ try:
+ 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.flush()
- os.rename(tmpname, file_name)
+ 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:
- f.close()
- finally:
- out.close()
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
+
+
+def AddHostToEtcHosts(hostname):
+ """Wrapper around SetEtcHostsEntry.
+
+ """
+ hi = HostInfo(name=hostname)
+ SetEtcHostsEntry(constants.ETC_HOSTS, hi.ip, hi.name, [hi.ShortName()])
+
+
+def RemoveEtcHostsEntry(file_name, hostname):
+ """Removes a hostname from /etc/hosts.
+
+ IP addresses without names are removed from the file.
+ """
+ fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
+ try:
+ out = os.fdopen(fd, 'w')
+ try:
+ f = open(file_name, 'r')
+ try:
+ for line in f:
+ fields = line.split()
+ if len(fields) > 1 and not fields[0].startswith('#'):
+ names = fields[1:]
+ if hostname in names:
+ while hostname in names:
+ names.remove(hostname)
+ if 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()
+ finally:
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
+
+
+def RemoveHostFromEtcHosts(hostname):
+ """Wrapper around RemoveEtcHostsEntry.
+
+ """
+ hi = HostInfo(name=hostname)
+ RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.name)
+ RemoveEtcHostsEntry(constants.ETC_HOSTS, hi.ShortName())
def CreateBackup(file_name):
file_name)
prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time()))
- dir = os.path.dirname(file_name)
+ dir_name = os.path.dirname(file_name)
fsrc = open(file_name, 'rb')
try:
- (fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir)
+ (fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name)
fdst = os.fdopen(fd, 'wb')
try:
shutil.copyfileobj(fsrc, fdst)
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(uid, default=None):
- """Try to get the homedir of the given user id.
+def GetHomeDir(user, default=None):
+ """Try to get the homedir of the given user.
+
+ The user can be passed either as a string (denoting the name) or as
+ an integer (denoting the user id). If the user is not found, the
+ 'default' argument is returned, which defaults to None.
"""
try:
- result = pwd.getpwuid(uid)
+ if isinstance(user, basestring):
+ result = pwd.getpwnam(user)
+ elif isinstance(user, (int, long)):
+ result = pwd.getpwuid(user)
+ else:
+ raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" %
+ type(user))
except KeyError:
return default
return result.pw_dir
-def GetUUID():
+def NewUUID():
"""Returns a random UUID.
"""
return f.read(128).rstrip("\n")
finally:
f.close()
+
+
+def WriteFile(file_name, fn=None, data=None,
+ mode=None, uid=-1, gid=-1,
+ atime=None, mtime=None,
+ check_abspath=True, dry_run=False, backup=False):
+ """(Over)write a file atomically.
+
+ The file_name and either fn (a function taking one argument, the
+ file descriptor, and which should write the data to it) or data (the
+ contents of the file) must be passed. The other arguments are
+ optional and allow setting the file mode, owner and group, and the
+ mtime/atime of the file.
+
+ If the function doesn't raise an exception, it has succeeded and the
+ target file has the new contents. If the file has raised an
+ exception, an existing target file should be unmodified and the
+ temporary file should be removed.
+
+ """
+ if check_abspath and not os.path.isabs(file_name):
+ raise errors.ProgrammerError("Path passed to WriteFile is not"
+ " absolute: '%s'" % file_name)
+
+ if [fn, data].count(None) != 1:
+ raise errors.ProgrammerError("fn or data required")
+
+ if [atime, mtime].count(None) == 1:
+ raise errors.ProgrammerError("Both atime and mtime must be either"
+ " set or None")
+
+ if backup and not dry_run and os.path.isfile(file_name):
+ CreateBackup(file_name)
+
+ dir_name, base_name = os.path.split(file_name)
+ fd, new_name = tempfile.mkstemp('.new', base_name, dir_name)
+ # here we need to make sure we remove the temp file, if any error
+ # leaves it in place
+ try:
+ if uid != -1 or gid != -1:
+ os.chown(new_name, uid, gid)
+ if mode:
+ os.chmod(new_name, mode)
+ if data is not None:
+ os.write(fd, data)
+ else:
+ fn(fd)
+ os.fsync(fd)
+ if atime is not None and mtime is not None:
+ os.utime(new_name, (atime, mtime))
+ if not dry_run:
+ os.rename(new_name, file_name)
+ finally:
+ os.close(fd)
+ RemoveFile(new_name)
+
+
+def all(seq, pred=bool):
+ "Returns True if pred(x) is True for every element in the iterable"
+ for elem in itertools.ifilterfalse(pred, seq):
+ return False
+ return True
+
+
+def any(seq, pred=bool):
+ "Returns True if pred(x) is True for at least one element in the iterable"
+ 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
+
+
+def CheckVolumeGroupSize(vglist, vgname, minsize):
+ """Checks if the volume group list is valid.
+
+ A non-None return value means there's an error, and the return value
+ is the error message.
+
+ """
+ vgsize = vglist.get(vgname, None)
+ if vgsize is None:
+ return "volume group '%s' missing" % vgname
+ elif vgsize < minsize:
+ return ("volume group '%s' too small (%s MiB required, %d MiB found)" %
+ (vgname, minsize, vgsize))
+ return None
projects / ganeti-local / blobdiff