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mitogen/econtext/master.py

254 lines
8.3 KiB
Python

import commands
import getpass
import inspect
import logging
import os
import pkgutil
import re
import socket
import sys
import textwrap
import zlib
import econtext.core
LOG = logging.getLogger('econtext')
IOLOG = logging.getLogger('econtext.io')
RLOG = logging.getLogger('econtext.ctx')
DOCSTRING_RE = re.compile(r'""".+?"""', re.M | re.S)
COMMENT_RE = re.compile(r'^\s*#.*$', re.M)
def MinimizeSource(source):
subber = lambda match: '""' + ('\n' * match.group(0).count('\n'))
source = DOCSTRING_RE.sub(subber, source)
source = COMMENT_RE.sub('\n', source)
return source.replace(' ', '\t')
def GetChildModules(module, prefix):
it = pkgutil.iter_modules(module.__path__, prefix)
return [name for _, name, _ in it]
def CreateChild(*args):
"""Create a child process whose stdin/stdout is connected to a socket,
returning `(pid, socket_obj)`."""
parentfp, childfp = socket.socketpair()
pid = os.fork()
if not pid:
os.dup2(childfp.fileno(), 0)
os.dup2(childfp.fileno(), 1)
childfp.close()
parentfp.close()
os.execvp(args[0], args)
raise SystemExit
childfp.close()
LOG.debug('CreateChild() child %d fd %d, parent %d, args %r',
pid, parentfp.fileno(), os.getpid(), args)
return pid, parentfp
class Listener(econtext.core.BasicStream):
def __init__(self, broker, address=None, backlog=30):
self._broker = broker
self._sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self._sock.bind(address or ('0.0.0.0', 0))
self._sock.listen(backlog)
econtext.core.set_cloexec(self._sock.fileno())
self._listen_addr = self._sock.getsockname()
self.read_side = econtext.core.Side(self, self._sock.fileno())
broker.UpdateStream(self)
def Receive(self):
sock, addr = self._sock.accept()
context = Context(self._broker, name=addr)
stream = econtext.core.Stream(context)
stream.Accept(sock.fileno(), sock.fileno())
class LogForwarder(object):
def __init__(self, context):
self._context = context
self._context.AddHandleCB(self.ForwardLog,
handle=econtext.core.FORWARD_LOG)
self._log = RLOG.getChild(self._context.name)
def ForwardLog(self, data):
if data == econtext.core._DEAD:
return
name, level, s = data
self._log.log(level, '%s: %s', name, s)
class ModuleResponder(object):
def __init__(self, context):
self._context = context
self._context.AddHandleCB(self.GetModule,
handle=econtext.core.GET_MODULE)
def GetModule(self, data):
if data == econtext.core._DEAD:
return
reply_to, fullname = data
LOG.debug('GetModule(%r, %r)', reply_to, fullname)
try:
module = __import__(fullname, fromlist=[''])
is_pkg = getattr(module, '__path__', None) is not None
path = inspect.getsourcefile(module)
try:
source = inspect.getsource(module)
except IOError:
if not is_pkg:
raise
source = '\n'
if is_pkg:
prefix = module.__name__ + '.'
present = GetChildModules(module, prefix)
else:
present = None
compressed = zlib.compress(MinimizeSource(source))
reply = (is_pkg, present, path, compressed)
self._context.Enqueue(reply_to, reply)
except Exception:
LOG.exception('While importing %r', fullname)
self._context.Enqueue(reply_to, None)
class LocalStream(econtext.core.Stream):
"""
Base for streams capable of starting new slaves.
"""
#: The path to the remote Python interpreter.
python_path = sys.executable
def __init__(self, context):
super(LocalStream, self).__init__(context)
self._permitted_classes = set([('econtext.core', 'CallError')])
def _FindGlobal(self, module_name, class_name):
"""Return the class implementing `module_name.class_name` or raise
`StreamError` if the module is not whitelisted."""
if (module_name, class_name) not in self._permitted_classes:
raise econtext.core.StreamError(
'%r attempted to unpickle %r in module %r',
self._context, class_name, module_name)
return getattr(sys.modules[module_name], class_name)
def AllowClass(self, module_name, class_name):
"""Add `module_name` to the list of permitted modules."""
self._permitted_modules.add((module_name, class_name))
# base64'd and passed to 'python -c'. It forks, dups 0->100, creates a
# pipe, then execs a new interpreter with a custom argv. CONTEXT_NAME is
# replaced with the context name. Optimized for size.
def _FirstStage():
import os,sys,zlib
R,W=os.pipe()
if os.fork():
os.dup2(0,100)
os.dup2(R,0)
os.close(R)
os.close(W)
os.execv(sys.executable,('econtext:'+CONTEXT_NAME,))
else:
os.fdopen(W,'wb',0).write(zlib.decompress(sys.stdin.read(input())))
print 'OK'
sys.exit(0)
def GetBootCommand(self):
name = self._context.remote_name
if name is None:
name = '%s@%s:%d'
name %= (getpass.getuser(), socket.gethostname(), os.getpid())
source = inspect.getsource(self._FirstStage)
source = textwrap.dedent('\n'.join(source.strip().split('\n')[1:]))
source = source.replace(' ', '\t')
source = source.replace('CONTEXT_NAME', repr(name))
encoded = source.encode('base64').replace('\n', '')
return [self.python_path, '-c',
'exec "%s".decode("base64")' % (encoded,)]
def __repr__(self):
return '%s(%s)' % (self.__class__.__name__, self._context)
def GetPreamble(self):
source = inspect.getsource(econtext.core)
source += '\nExternalContext().main%r\n' % ((
self._context.key,
LOG.level or logging.getLogger().level or logging.INFO,
),)
compressed = zlib.compress(MinimizeSource(source))
return str(len(compressed)) + '\n' + compressed
def Connect(self):
LOG.debug('%r.Connect()', self)
pid, sock = CreateChild(*self.GetBootCommand())
self.read_side = econtext.core.Side(self, os.dup(sock.fileno()))
self.write_side = self.read_side
sock.close()
LOG.debug('%r.Connect(): child process stdin/stdout=%r',
self, self.read_side.fd)
econtext.core.write_all(self.write_side.fd, self.GetPreamble())
assert os.read(self.read_side.fd, 3) == 'OK\n'
class SSHStream(LocalStream):
#: The path to the SSH binary.
ssh_path = 'ssh'
def GetBootCommand(self):
bits = [self.ssh_path]
if self._context.username:
bits += ['-l', self._context.username]
bits.append(self._context.hostname)
base = super(SSHStream, self).GetBootCommand()
return bits + map(commands.mkarg, base)
class Broker(econtext.core.Broker):
def CreateListener(self, address=None, backlog=30):
"""Listen on `address `for connections from newly spawned contexts."""
self._listener = Listener(self, address, backlog)
def GetLocal(self, name='default'):
"""Get the named context running on the local machine, creating it if
it does not exist."""
context = Context(self, name)
context.stream = LocalStream(context)
context.stream.Connect()
return self.Register(context)
def GetRemote(self, hostname, username, name=None, python_path=None):
"""Get the named remote context, creating it if it does not exist."""
if name is None:
name = hostname
context = Context(self, name, hostname, username)
context.stream = SSHStream(context)
if python_path:
context.stream.python_path = python_path
context.stream.Connect()
return self.Register(context)
class Context(econtext.core.Context):
def __init__(self, *args, **kwargs):
super(Context, self).__init__(*args, **kwargs)
self.responder = ModuleResponder(self)
self.log_forwarder = LogForwarder(self)
def Disconnect(self):
self.stream = None