ray/python/ray/util/rpdb.py

# Some code in this file is from
# https://github.com/ionelmc/python-remote-pdb/blob/07d563331c4ab9eb45731bb272b158816d98236e/src/remote_pdb.py
# (BSD 2-Clause "Simplified" License)

import errno
import inspect
import json
import logging
import os
import re
import socket
import sys
import uuid
from pdb import Pdb
import setproctitle
import traceback

from ray.experimental.internal_kv import _internal_kv_del, _internal_kv_put

PY3 = sys.version_info[0] == 3
log = logging.getLogger(__name__)


def cry(message, stderr=sys.__stderr__):
    print(message, file=stderr)
    stderr.flush()


class LF2CRLF_FileWrapper(object):
    def __init__(self, connection):
        self.connection = connection
        self.stream = fh = connection.makefile("rw")
        self.read = fh.read
        self.readline = fh.readline
        self.readlines = fh.readlines
        self.close = fh.close
        self.flush = fh.flush
        self.fileno = fh.fileno
        if hasattr(fh, "encoding"):
            self._send = lambda data: connection.sendall(
                data.encode(fh.encoding))
        else:
            self._send = connection.sendall

    @property
    def encoding(self):
        return self.stream.encoding

    def __iter__(self):
        return self.stream.__iter__()

    def write(self, data, nl_rex=re.compile("\r?\n")):
        data = nl_rex.sub("\r\n", data)
        self._send(data)

    def writelines(self, lines, nl_rex=re.compile("\r?\n")):
        for line in lines:
            self.write(line, nl_rex)


class RemotePdb(Pdb):
    """
    This will run pdb as a ephemeral telnet service. Once you connect no one
    else can connect. On construction this object will block execution till a
    client has connected.
    Based on https://github.com/tamentis/rpdb I think ...
    To use this::
        RemotePdb(host="0.0.0.0", port=4444).set_trace()
    Then run: telnet 127.0.0.1 4444
    """
    active_instance = None

    def __init__(self, host, port, patch_stdstreams=False, quiet=False):
        self._quiet = quiet
        self._patch_stdstreams = patch_stdstreams
        self._listen_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self._listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
                                       True)
        self._listen_socket.bind((host, port))

    def listen(self):
        if not self._quiet:
            cry("RemotePdb session open at %s:%s, "
                "use 'ray debug' to connect..." %
                self._listen_socket.getsockname())
        self._listen_socket.listen(1)
        connection, address = self._listen_socket.accept()
        if not self._quiet:
            cry("RemotePdb accepted connection from %s." % repr(address))
        self.handle = LF2CRLF_FileWrapper(connection)
        Pdb.__init__(
            self, completekey="tab", stdin=self.handle, stdout=self.handle)
        self.backup = []
        if self._patch_stdstreams:
            for name in (
                    "stderr",
                    "stdout",
                    "__stderr__",
                    "__stdout__",
                    "stdin",
                    "__stdin__",
            ):
                self.backup.append((name, getattr(sys, name)))
                setattr(sys, name, self.handle)
        RemotePdb.active_instance = self

    def __restore(self):
        if self.backup and not self._quiet:
            cry("Restoring streams: %s ..." % self.backup)
        for name, fh in self.backup:
            setattr(sys, name, fh)
        self.handle.close()
        RemotePdb.active_instance = None

    def do_quit(self, arg):
        self.__restore()
        return Pdb.do_quit(self, arg)

    do_q = do_exit = do_quit

    def set_trace(self, frame=None):
        if frame is None:
            frame = sys._getframe().f_back
        try:
            Pdb.set_trace(self, frame)
        except IOError as exc:
            if exc.errno != errno.ECONNRESET:
                raise

    def post_mortem(self, traceback=None):
        # See https://github.com/python/cpython/blob/
        # 022bc7572f061e1d1132a4db9d085b29707701e7/Lib/pdb.py#L1617
        try:
            t = sys.exc_info()[2]
            self.reset()
            Pdb.interaction(self, None, t)
        except IOError as exc:
            if exc.errno != errno.ECONNRESET:
                raise


def connect_ray_pdb(host=None, port=None, patch_stdstreams=False, quiet=None):
    """
    Opens a remote PDB on first available port.
    """
    if host is None:
        host = os.environ.get("REMOTE_PDB_HOST", "127.0.0.1")
    if port is None:
        port = int(os.environ.get("REMOTE_PDB_PORT", "0"))
    if quiet is None:
        quiet = bool(os.environ.get("REMOTE_PDB_QUIET", ""))
    rdb = RemotePdb(
        host=host, port=port, patch_stdstreams=patch_stdstreams, quiet=quiet)
    sockname = rdb._listen_socket.getsockname()
    pdb_address = "{}:{}".format(sockname[0], sockname[1])
    parentframeinfo = inspect.getouterframes(inspect.currentframe())[2]
    data = {
        "proctitle": setproctitle.getproctitle(),
        "pdb_address": pdb_address,
        "filename": parentframeinfo.filename,
        "lineno": parentframeinfo.lineno,
        "traceback": "\n".join(traceback.format_exception(*sys.exc_info()))
    }
    breakpoint_uuid = uuid.uuid4()
    _internal_kv_put(
        "RAY_PDB_{}".format(breakpoint_uuid), json.dumps(data), overwrite=True)
    rdb.listen()
    _internal_kv_del("RAY_PDB_{}".format(breakpoint_uuid))

    return rdb


def set_trace(host=None, port=None, patch_stdstreams=False, quiet=None):
    frame = sys._getframe().f_back
    rdb = connect_ray_pdb(host, port, patch_stdstreams, quiet)
    rdb.set_trace(frame=frame)


def post_mortem(host=None, port=None, patch_stdstreams=False, quiet=None):
    rdb = connect_ray_pdb(host, port, patch_stdstreams, quiet)
    rdb.post_mortem()