X-Git-Url: https://scripts.mit.edu/gitweb/wizard.git/blobdiff_plain/e44406f8baa8d92acedfc69c528d6afe41af22e1..6554c6378a6e801b4fe47c50688cdae1d627bc18:/wizard/util.py diff --git a/wizard/util.py b/wizard/util.py index 2d9c72f..6c9764d 100644 --- a/wizard/util.py +++ b/wizard/util.py @@ -17,6 +17,10 @@ import itertools import signal import httplib import urllib +import time +import logging +import random +import string import wizard @@ -57,6 +61,15 @@ class Counter(object): return self.dict[key] def __iter__(self): return self.dict.__iter__() + def max(self): + """Returns the max counter value seen.""" + return max(self.dict.values()) + def sum(self): + """Returns the sum of all counter values.""" + return sum(self.dict.values()) + def keys(self): + """Returns the keys of counters.""" + return self.dict.keys() class PipeToLess(object): """ @@ -87,17 +100,47 @@ class LockDirectory(object): """ Context for locking a directory. """ - def __init__(self, lockfile): + def __init__(self, lockfile, expiry = 3600): self.lockfile = lockfile + self.expiry = expiry # by default an hour def __enter__(self): - try: - os.open(self.lockfile, os.O_CREAT | os.O_EXCL) - except OSError as e: - if e.errno == errno.EEXIST: - raise DirectoryLockedError(os.getcwd()) - elif e.errno == errno.EACCES: - raise command.PermissionsError(os.getcwd()) - raise + # It's A WAVY + for i in range(0, 3): + try: + os.open(self.lockfile, os.O_CREAT | os.O_EXCL) + open(self.lockfile, "w").write("%d" % os.getpid()) + except OSError as e: + if e.errno == errno.EEXIST: + # There is a possibility of infinite recursion, but we + # expect it to be unlikely, and not harmful if it does happen + with LockDirectory(self.lockfile + "_"): + # See if we can break the lock + try: + pid = open(self.lockfile, "r").read().strip() + if not os.path.exists("/proc/%s" % pid): + # break the lock, try again + logging.warning("Breaking orphaned lock at %s", self.lockfile) + os.unlink(self.lockfile) + continue + try: + # check if the file is expiry old, if so, break the lock, try again + if time.time() - os.stat(self.lockfile).st_mtime > self.expiry: + logging.warning("Breaking stale lock at %s", self.lockfile) + os.unlink(self.lockfile) + continue + except OSError as e: + if e.errno == errno.ENOENT: + continue + raise + except IOError: + # oh hey, it went away; try again + continue + raise DirectoryLockedError(os.getcwd()) + elif e.errno == errno.EACCES: + raise PermissionsError(os.getcwd()) + raise + return + raise DirectoryLockedError(os.getcwd()) def __exit__(self, *args): try: os.unlink(self.lockfile) @@ -152,10 +195,7 @@ def get_exception_name(output): continue if cue: cue = False - if line[-1] == ":": - result = line[:-1] - else: - result = line + return line.partition(':')[0] return result def get_dir_uid(dir): @@ -172,9 +212,13 @@ def get_dir_owner(dir = "."): only works on scripts servers when querying directories that live on AFS. """ - pwentry = pwd.getpwuid(get_dir_uid(dir)) - # XXX: Error handling! - return pwentry.pw_name + uid = get_dir_uid(dir) + try: + pwentry = pwd.getpwuid(uid) + return pwentry.pw_name + except KeyError: + # do an pts query to get the name + return subprocess.Popen(['pts', 'examine', str(uid)], stdout=subprocess.PIPE).communicate()[0].partition(",")[0].partition(": ")[2] def get_revision(): """Returns the commit ID of the current Wizard install.""" @@ -283,6 +327,8 @@ def get_git_footer(): def safe_unlink(file): """Moves a file/dir to a backup location.""" + if not os.path.exists(file): + return None prefix = "%s.bak" % file name = None for i in itertools.count(): @@ -292,18 +338,45 @@ def safe_unlink(file): os.rename(file, name) return name +def soft_unlink(file): + """Unlink a file, but don't complain if it doesn't exist.""" + try: + os.unlink(file) + except OSError: + pass + def fetch(host, path, subpath, post=None): - h = httplib.HTTPConnection(host) - fullpath = path + "/" + subpath - if post: - headers = {"Content-type": "application/x-www-form-urlencoded"} - h.request("POST", fullpath, urllib.urlencode(post), headers) - else: - h.request("GET", fullpath) - r = h.getresponse() - data = r.read() - h.close() - return data + try: + # XXX: Special case if it's https; not sure why this data isn't + # passed + h = httplib.HTTPConnection(host) + fullpath = path.rstrip("/") + "/" + subpath.lstrip("/") # to be lenient about input we accept + if post: + headers = {"Content-type": "application/x-www-form-urlencoded"} + h.request("POST", fullpath, urllib.urlencode(post), headers) + else: + h.request("GET", fullpath) + r = h.getresponse() + data = r.read() + h.close() + return data + except socket.gaierror as e: + if e.errno == socket.EAI_NONAME: + raise DNSError(host) + else: + raise + +def mixed_newlines(filename): + """Returns ``True`` if ``filename`` has mixed newlines.""" + f = open(filename, "U") # requires universal newline support + f.read() + ret = isinstance(f.newlines, tuple) + f.close() # just to be safe + return ret + +def random_key(length=30): + """Generates a random alphanumeric key of ``length`` size.""" + return ''.join(random.choice(string.letters + string.digits) for i in xrange(length)) class NoOperatorInfo(wizard.Error): """No information could be found about the operator from Kerberos.""" @@ -325,3 +398,14 @@ ERROR: Could not acquire lock on directory. Maybe there is another migration process running? """ +class DNSError(socket.gaierror): + errno = socket.EAI_NONAME + #: Hostname that could not resolve name + host = None + def __init__(self, host): + self.host = host + def __str__(self): + return """ + +ERROR: Could not resolve hostname %s. +""" % self.host