"""Detects whether or not an argument list invokes a Python program."""
return args[0] == "python" or args[0] == "wizard"
-def drop_priviledges(dir, options):
+def drop_priviledges(dir, log_file):
"""
Checks if we are running as root. If we are, attempt to drop
priviledges to the user who owns ``dir``, by re-calling
itself using sudo with exec, such that the new process subsumes our
- current one.
+ current one. If ``log_file`` is passed, the file is chown'ed
+ to the user we are dropping priviledges to, so the subprocess
+ can write to it.
"""
if os.getuid():
return
args.append("%s=%s" % (k,v))
args += sys.argv
logging.debug("Dropping priviledges")
- if options.log_file: os.chown(options.log_file, uid, -1)
+ if log_file: os.chown(log_file, uid, -1)
os.execlp('sudo', 'sudo', '-u', '#' + str(uid), *args)
class Shell(object):
"""
def __init__(self, dry = False):
self.dry = dry
+ self.cwd = None
def call(self, *args, **kwargs):
"""
Performs a system call. The actual executable and options should
specify this if you are using another wrapper around this function).
:param log: if True, we log the call as INFO, if False, we log the call
as DEBUG, otherwise, we detect based on ``strip``.
+ :param stdout:
+ :param stderr:
+ :param stdin: a file-type object that will be written to or read from as a pipe.
:returns: a tuple of strings ``(stdout, stderr)``, or a string ``stdout``
if ``strip`` is specified.
>>> sh.call("cat", input='Foobar')
('Foobar', '')
"""
- if hasattr(self, "_wait"):
- self._wait()
+ self._wait()
kwargs.setdefault("interactive", False)
kwargs.setdefault("strip", False)
kwargs.setdefault("python", None)
kwargs.setdefault("log", None)
+ kwargs.setdefault("stdout", subprocess.PIPE)
+ kwargs.setdefault("stdin", subprocess.PIPE)
+ kwargs.setdefault("stderr", subprocess.PIPE)
msg = "Running `" + ' '.join(args) + "`"
if kwargs["strip"] and not kwargs["log"] is True or kwargs["log"] is False:
logging.debug(msg)
stdin=sys.stdin
stderr=sys.stderr
else:
- stdout=subprocess.PIPE
- stdin=subprocess.PIPE
- stderr=subprocess.PIPE
+ stdout=kwargs["stdout"]
+ stdin=kwargs["stdin"]
+ stderr=kwargs["stderr"]
# XXX: There is a possible problem here where we can fill up
# the kernel buffer if we have 64KB of data. This shouldn't
# be a problem, and the fix for such case would be to write to
# ourself, and then setting up a
# SIGCHILD handler to write a single byte to the pipe to get
# us out of select() when a subprocess exits.
- proc = subprocess.Popen(args, stdout=stdout, stderr=stderr, stdin=stdin)
- if hasattr(self, "_async"):
- self._async(proc, args, **kwargs)
+ proc = subprocess.Popen(args, stdout=stdout, stderr=stderr, stdin=stdin, cwd=self.cwd, )
+ if self._async(proc, args, **kwargs):
return proc
stdout, stderr = proc.communicate(kwargs["input"])
+ # can occur if we were doing interactive communication; i.e.
+ # we didn't pass in PIPE.
+ if stdout is None:
+ stdout = ""
+ if stderr is None:
+ stderr = ""
if not kwargs["interactive"]:
if kwargs["strip"]:
self._log(None, stderr)
else: eclass = CallError
raise eclass(proc.returncode, args, stdout, stderr)
if kwargs["strip"]:
- return stdout.rstrip("\n")
+ return str(stdout).rstrip("\n")
return (stdout, stderr)
def _log(self, stdout, stderr):
"""Logs the standard output and standard input from a command."""
logging.debug("STDOUT:\n" + stdout)
if stderr:
logging.debug("STDERR:\n" + stderr)
+ def _wait(self):
+ pass
+ def _async(self, *args, **kwargs):
+ return False
def callAsUser(self, *args, **kwargs):
"""
Performs a system call as a different user. This is only possible
on working directory context. Keyword arguments are the
same as :meth:`call`.
"""
+ if os.getuid():
+ return self.call(*args, **kwargs)
uid = os.stat(os.getcwd()).st_uid
# consider also checking ruid?
if uid != os.geteuid():
"""
kwargs["strip"] = True
return self.call(*args, **kwargs)
+ def setcwd(self, cwd):
+ """
+ Sets the directory processes are executed in. This sets a value
+ to be passed as the ``cwd`` argument to ``subprocess.Popen``.
+ """
+ self.cwd = cwd
class ParallelShell(Shell):
"""
self.running = {}
self.max = max # maximum of commands to run in parallel
@staticmethod
- def make(self, no_parallelize, max):
+ def make(no_parallelize, max):
"""Convenience method oriented towards command modules."""
if no_parallelize:
return DummyParallelShell()
execution. See :meth:`Shell.call` source code for details.
"""
self.running[proc.pid] = (proc, args, python, on_success, on_error)
+ return True # so that the parent function returns
def _wait(self):
"""
Blocking call that waits for an open subprocess slot. This is
automatically called by :meth:`Shell.call`.
"""
- # XXX: This API sucks; the actuall call/callAsUser call should
+ # XXX: This API sucks; the actual call/callAsUser call should
# probably block automatically (unless I have a good reason not to)
# bail out immediately on initial ramp up
if len(self.running) < self.max: return
return
on_success(stdout, stderr)
+# Setup a convenience global instance
+shell = Shell()
+call = shell.call
+callAsUser = shell.callAsUser
+safeCall = shell.safeCall
+eval = shell.eval
class DummyParallelShell(ParallelShell):
"""Same API as :class:`ParallelShell`, but doesn't actually
scripts.mit.edu / wizard.git / blobdiff