-#!/usr/bin/python
+#
#
# Copyright (C) 2006, 2007 Google Inc.
"""Ganeti small utilities
+
"""
import tempfile
import shutil
import errno
+import pwd
+import itertools
from ganeti import logger
from ganeti import errors
+
_locksheld = []
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
class HostInfo:
- """Class holding host info as returned by gethostbyname
+ """Class implementing resolver and hostname functionality
"""
- def __init__(self, name, aliases, ipaddrs):
+ def __init__(self, name=None):
"""Initialize the host name object.
- Arguments are the same as returned by socket.gethostbyname_ex()
+ If the name argument is not passed, it will use this system's
+ name.
"""
- self.name = name
- self.aliases = aliases
- self.ipaddrs = ipaddrs
+ if name is None:
+ name = self.SysName()
+
+ self.query = name
+ self.name, self.aliases, self.ipaddrs = self.LookupHostname(name)
self.ip = self.ipaddrs[0]
+ def ShortName(self):
+ """Returns the hostname without domain.
-def LookupHostname(hostname):
- """Look up hostname
+ """
+ return self.name.split('.')[0]
- Args:
- hostname: hostname to look up, can be also be a non FQDN
+ @staticmethod
+ def SysName():
+ """Return the current system's name.
- Returns:
- a HostInfo object
+ This is simply a wrapper over socket.gethostname()
- """
- try:
- (name, aliases, ipaddrs) = socket.gethostbyname_ex(hostname)
- except socket.gaierror:
- # hostname not found in DNS
- return None
+ """
+ return socket.gethostname()
+
+ @staticmethod
+ def LookupHostname(hostname):
+ """Look up hostname
- return HostInfo(name, aliases, ipaddrs)
+ Args:
+ hostname: hostname to look up
+
+ Returns:
+ a tuple (name, aliases, ipaddrs) as returned by socket.gethostbyname_ex
+ in case of errors in resolving, we raise a ResolverError
+
+ """
+ try:
+ result = socket.gethostbyname_ex(hostname)
+ except socket.gaierror, err:
+ # hostname not found in DNS
+ raise errors.ResolverError(hostname, err.args[0], err.args[1])
+
+ return result
def ListVolumeGroups():
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.
+
+ """
+ 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 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 CreateBackup(file_name):
raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" %
file_name)
- # Warning: the following code contains a race condition when we create more
- # than one backup of the same file in a second.
- backup_name = file_name + '.backup-%d' % int(time.time())
- shutil.copyfile(file_name, backup_name)
+ prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time()))
+ dir_name = os.path.dirname(file_name)
+
+ fsrc = open(file_name, 'rb')
+ try:
+ (fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name)
+ fdst = os.fdopen(fd, 'wb')
+ try:
+ shutil.copyfileobj(fsrc, fdst)
+ finally:
+ fdst.close()
+ finally:
+ fsrc.close()
+
return backup_name
return ' '.join([ShellQuote(i) for i in args])
-def _ParseIpOutput(output):
- """Parsing code for GetLocalIPAddresses().
-
- This function is split out, so we can unit test it.
-
- """
- re_ip = re.compile('^(\d+\.\d+\.\d+\.\d+)(?:/\d+)$')
-
- ips = []
- for line in output.splitlines(False):
- fields = line.split()
- if len(line) < 4:
- continue
- m = re_ip.match(fields[3])
- if m:
- ips.append(m.group(1))
-
- return ips
-
-
-def GetLocalIPAddresses():
- """Gets a list of all local IP addresses.
-
- Should this break one day, a small Python module written in C could
- use the API call getifaddrs().
- """
- result = RunCmd(["ip", "-family", "inet", "-oneline", "addr", "show"])
- if result.failed:
- raise errors.OpExecError("Command '%s' failed, error: %s,"
- " output: %s" % (result.cmd, result.fail_reason, result.output))
-
- return _ParseIpOutput(result.output)
-
-
-def TcpPing(source, target, port, timeout=10, live_port_needed=True):
+def TcpPing(source, target, port, timeout=10, live_port_needed=False):
"""Simple ping implementation using TCP connect(2).
Try to do a TCP connect(2) from the specified source IP to the specified
success = (not live_port_needed) and (errcode == errno.ECONNREFUSED)
return success
+
+
+def ListVisibleFiles(path):
+ """Returns a list of all visible files in a directory.
+
+ """
+ return [i for i in os.listdir(path) if not i.startswith(".")]
+
+
+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:
+ 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 NewUUID():
+ """Returns a random UUID.
+
+ """
+ f = open("/proc/sys/kernel/random/uuid", "r")
+ try:
+ 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):
+ """(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 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")
+
+
+ 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))
+ 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
projects / ganeti-local / blobdiff