Uploaded Test files

venv/Lib/site-packages/terminado/__init__.py

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+"""Terminals served to xterm.js using Tornado websockets"""
+
+# Copyright (c) Jupyter Development Team
+# Copyright (c) 2014, Ramalingam Saravanan <sarava@sarava.net>
+# Distributed under the terms of the Simplified BSD License.
+
+from .websocket import TermSocket
+from .management import (TermManagerBase, SingleTermManager,
+                         UniqueTermManager, NamedTermManager)
+
+import logging
+# Prevent a warning about no attached handlers in Python 2
+logging.getLogger(__name__).addHandler(logging.NullHandler())
+
+__version__ = '0.9.1'

venv/Lib/site-packages/terminado/management.py

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+"""Terminal management for exposing terminals to a web interface using Tornado.
+"""
+# Copyright (c) Jupyter Development Team
+# Copyright (c) 2014, Ramalingam Saravanan <sarava@sarava.net>
+# Distributed under the terms of the Simplified BSD License.
+
+from __future__ import absolute_import, print_function
+
+import sys
+if sys.version_info[0] < 3:
+    byte_code = ord
+else:
+    def byte_code(x): return x
+    unicode = str
+
+from collections import deque
+import itertools
+import logging
+import os
+import signal
+
+try:
+    from ptyprocess import PtyProcessUnicode
+except ImportError:
+    from winpty import PtyProcess as PtyProcessUnicode
+
+from tornado import gen
+from tornado.ioloop import IOLoop
+
+ENV_PREFIX = "PYXTERM_"         # Environment variable prefix
+
+DEFAULT_TERM_TYPE = "xterm"
+
+
+class PtyWithClients(object):
+    def __init__(self, argv, env=[], cwd=None):
+        self.clients = []
+        # If you start the process and then construct this object from it,
+        #  output generated by the process prior to the object's creation
+        #  is lost.  Hence the change from 0.8.3.
+        # Buffer output until a client connects; then let the client
+        #  drain the buffer.
+        # We keep the same read_buffer as before
+        self.read_buffer = deque([], maxlen=10)
+        self.preopen_buffer = deque([])
+        self.ptyproc = PtyProcessUnicode.spawn(argv, env=env, cwd=cwd)
+
+    def resize_to_smallest(self):
+        """Set the terminal size to that of the smallest client dimensions.
+
+        A terminal not using the full space available is much nicer than a
+        terminal trying to use more than the available space, so we keep it 
+        sized to the smallest client.
+        """
+        minrows = mincols = 10001
+        for client in self.clients:
+            rows, cols = client.size
+            if rows is not None and rows < minrows:
+                minrows = rows
+            if cols is not None and cols < mincols:
+                mincols = cols
+
+        if minrows == 10001 or mincols == 10001:
+            return
+
+        rows, cols = self.ptyproc.getwinsize()
+        if (rows, cols) != (minrows, mincols):
+            self.ptyproc.setwinsize(minrows, mincols)
+
+    def kill(self, sig=signal.SIGTERM):
+        """Send a signal to the process in the pty"""
+        self.ptyproc.kill(sig)
+
+    def killpg(self, sig=signal.SIGTERM):
+        """Send a signal to the process group of the process in the pty"""
+        if os.name == 'nt':
+            return self.ptyproc.kill(sig)
+        pgid = os.getpgid(self.ptyproc.pid)
+        os.killpg(pgid, sig)
+
+    @gen.coroutine
+    def terminate(self, force=False):
+        '''This forces a child process to terminate. It starts nicely with
+        SIGHUP and SIGINT. If "force" is True then moves onto SIGKILL. This
+        returns True if the child was terminated. This returns False if the
+        child could not be terminated. '''
+        if os.name == 'nt':
+            signals = [signal.SIGINT, signal.SIGTERM]
+        else:
+            signals = [signal.SIGHUP, signal.SIGCONT, signal.SIGINT,
+                       signal.SIGTERM]
+
+        loop = IOLoop.current()
+        def sleep(): return gen.sleep(self.ptyproc.delayafterterminate)
+
+        if not self.ptyproc.isalive():
+            raise gen.Return(True)
+        try:
+            for sig in signals:
+                self.kill(sig)
+                yield sleep()
+                if not self.ptyproc.isalive():
+                    raise gen.Return(True)
+            if force:
+                self.kill(signal.SIGKILL)
+                yield sleep()
+                if not self.ptyproc.isalive():
+                    raise gen.Return(True)
+                else:
+                    raise gen.Return(False)
+            raise gen.Return(False)
+        except OSError:
+            # I think there are kernel timing issues that sometimes cause
+            # this to happen. I think isalive() reports True, but the
+            # process is dead to the kernel.
+            # Make one last attempt to see if the kernel is up to date.
+            yield sleep()
+            if not self.ptyproc.isalive():
+                raise gen.Return(True)
+            else:
+                raise gen.Return(False)
+
+
+def _update_removing(target, changes):
+    """Like dict.update(), but remove keys where the value is None.
+    """
+    for k, v in changes.items():
+        if v is None:
+            target.pop(k, None)
+        else:
+            target[k] = v
+
+
+class TermManagerBase(object):
+    """Base class for a terminal manager."""
+
+    def __init__(self, shell_command, server_url="", term_settings={},
+                 extra_env=None, ioloop=None):
+        self.shell_command = shell_command
+        self.server_url = server_url
+        self.term_settings = term_settings
+        self.extra_env = extra_env
+        self.log = logging.getLogger(__name__)
+
+        self.ptys_by_fd = {}
+
+        if ioloop is not None:
+            self.ioloop = ioloop
+        else:
+            import tornado.ioloop
+            self.ioloop = tornado.ioloop.IOLoop.instance()
+
+    def make_term_env(self, height=25, width=80, winheight=0, winwidth=0, **kwargs):
+        """Build the environment variables for the process in the terminal."""
+        env = os.environ.copy()
+        env["TERM"] = self.term_settings.get("type", DEFAULT_TERM_TYPE)
+        dimensions = "%dx%d" % (width, height)
+        if winwidth and winheight:
+            dimensions += ";%dx%d" % (winwidth, winheight)
+        env[ENV_PREFIX+"DIMENSIONS"] = dimensions
+        env["COLUMNS"] = str(width)
+        env["LINES"] = str(height)
+
+        if self.server_url:
+            env[ENV_PREFIX+"URL"] = self.server_url
+
+        if self.extra_env:
+            _update_removing(env, self.extra_env)
+
+        return env
+
+    def new_terminal(self, **kwargs):
+        """Make a new terminal, return a :class:`PtyWithClients` instance."""
+        options = self.term_settings.copy()
+        options['shell_command'] = self.shell_command
+        options.update(kwargs)
+        argv = options['shell_command']
+        env = self.make_term_env(**options)
+        cwd = options.get('cwd', None)
+        return PtyWithClients(argv, env, cwd)
+
+    def start_reading(self, ptywclients):
+        """Connect a terminal to the tornado event loop to read data from it."""
+        fd = ptywclients.ptyproc.fd
+        self.ptys_by_fd[fd] = ptywclients
+        self.ioloop.add_handler(fd, self.pty_read, self.ioloop.READ)
+
+    def on_eof(self, ptywclients):
+        """Called when the pty has closed.
+        """
+        # Stop trying to read from that terminal
+        fd = ptywclients.ptyproc.fd
+        self.log.info("EOF on FD %d; stopping reading", fd)
+        del self.ptys_by_fd[fd]
+        self.ioloop.remove_handler(fd)
+
+        # This closes the fd, and should result in the process being reaped.
+        ptywclients.ptyproc.close()
+
+    def pty_read(self, fd, events=None):
+        """Called by the event loop when there is pty data ready to read."""
+        ptywclients = self.ptys_by_fd[fd]
+        try:
+            s = ptywclients.ptyproc.read(65536)
+            client_list = ptywclients.clients
+            ptywclients.read_buffer.append(s)
+            if not client_list:
+                # No one to consume our output: buffer it.
+                ptywclients.preopen_buffer.append(s)
+                return
+            for client in ptywclients.clients:
+                client.on_pty_read(s)
+        except EOFError:
+            self.on_eof(ptywclients)
+            for client in ptywclients.clients:
+                client.on_pty_died()
+
+    def get_terminal(self, url_component=None):
+        """Override in a subclass to give a terminal to a new websocket connection
+
+        The :class:`TermSocket` handler works with zero or one URL components
+        (capturing groups in the URL spec regex). If it receives one, it is
+        passed as the ``url_component`` parameter; otherwise, this is None.
+        """
+        raise NotImplementedError
+
+    def client_disconnected(self, websocket):
+        """Override this to e.g. kill terminals on client disconnection.
+        """
+        pass
+
+    @gen.coroutine
+    def shutdown(self):
+        yield self.kill_all()
+
+    @gen.coroutine
+    def kill_all(self):
+        futures = []
+        for term in self.ptys_by_fd.values():
+            futures.append(term.terminate(force=True))
+        # wait for futures to finish
+        for f in futures:
+            yield f
+
+
+class SingleTermManager(TermManagerBase):
+    """All connections to the websocket share a common terminal."""
+
+    def __init__(self, **kwargs):
+        super(SingleTermManager, self).__init__(**kwargs)
+        self.terminal = None
+
+    def get_terminal(self, url_component=None):
+        if self.terminal is None:
+            self.terminal = self.new_terminal()
+            self.start_reading(self.terminal)
+        return self.terminal
+
+    @gen.coroutine
+    def kill_all(self):
+        yield super(SingleTermManager, self).kill_all()
+        self.terminal = None
+
+
+class MaxTerminalsReached(Exception):
+    def __init__(self, max_terminals):
+        self.max_terminals = max_terminals
+
+    def __str__(self):
+        return "Cannot create more than %d terminals" % self.max_terminals
+
+
+class UniqueTermManager(TermManagerBase):
+    """Give each websocket a unique terminal to use."""
+
+    def __init__(self, max_terminals=None, **kwargs):
+        super(UniqueTermManager, self).__init__(**kwargs)
+        self.max_terminals = max_terminals
+
+    def get_terminal(self, url_component=None):
+        if self.max_terminals and len(self.ptys_by_fd) >= self.max_terminals:
+            raise MaxTerminalsReached(self.max_terminals)
+
+        term = self.new_terminal()
+        self.start_reading(term)
+        return term
+
+    def client_disconnected(self, websocket):
+        """Send terminal SIGHUP when client disconnects."""
+        self.log.info("Websocket closed, sending SIGHUP to terminal.")
+        if websocket.terminal:
+            if os.name == 'nt':
+                websocket.terminal.kill()
+                # Immediately call the pty reader to process
+                # the eof and free up space
+                self.pty_read(websocket.terminal.ptyproc.fd)
+                return
+            websocket.terminal.killpg(signal.SIGHUP)
+
+
+class NamedTermManager(TermManagerBase):
+    """Share terminals between websockets connected to the same endpoint.
+    """
+
+    def __init__(self, max_terminals=None, **kwargs):
+        super(NamedTermManager, self).__init__(**kwargs)
+        self.max_terminals = max_terminals
+        self.terminals = {}
+
+    def get_terminal(self, term_name):
+        assert term_name is not None
+
+        if term_name in self.terminals:
+            return self.terminals[term_name]
+
+        if self.max_terminals and len(self.terminals) >= self.max_terminals:
+            raise MaxTerminalsReached(self.max_terminals)
+
+        # Create new terminal
+        self.log.info("New terminal with specified name: %s", term_name)
+        term = self.new_terminal()
+        term.term_name = term_name
+        self.terminals[term_name] = term
+        self.start_reading(term)
+        return term
+
+    name_template = "%d"
+
+    def _next_available_name(self):
+        for n in itertools.count(start=1):
+            name = self.name_template % n
+            if name not in self.terminals:
+                return name
+
+    def new_named_terminal(self, **kwargs):
+        name = self._next_available_name()
+        term = self.new_terminal(**kwargs)
+        self.log.info("New terminal with automatic name: %s", name)
+        term.term_name = name
+        self.terminals[name] = term
+        self.start_reading(term)
+        return name, term
+
+    def kill(self, name, sig=signal.SIGTERM):
+        term = self.terminals[name]
+        term.kill(sig)   # This should lead to an EOF
+
+    @gen.coroutine
+    def terminate(self, name, force=False):
+        term = self.terminals[name]
+        yield term.terminate(force=force)
+
+    def on_eof(self, ptywclients):
+        super(NamedTermManager, self).on_eof(ptywclients)
+        name = ptywclients.term_name
+        self.log.info("Terminal %s closed", name)
+        self.terminals.pop(name, None)
+
+    @gen.coroutine
+    def kill_all(self):
+        yield super(NamedTermManager, self).kill_all()
+        self.terminals = {}

venv/Lib/site-packages/terminado/tests/basic_test.py

@@ -0,0 +1,259 @@
+# basic_tests.py -- Basic unit tests for Terminado
+
+# Copyright (c) Jupyter Development Team
+# Copyright (c) 2014, Ramalingam Saravanan <sarava@sarava.net>
+# Distributed under the terms of the Simplified BSD License.
+
+from __future__ import absolute_import, print_function
+
+import unittest
+from terminado import *
+import tornado
+import tornado.httpserver
+from tornado.httpclient import HTTPError
+from tornado.ioloop import IOLoop
+import tornado.testing
+import datetime
+import logging
+import json
+import os
+import re
+import signal
+
+# We must set the policy for python >=3.8, see https://www.tornadoweb.org/en/stable/#installation
+# Snippet from https://github.com/tornadoweb/tornado/issues/2608#issuecomment-619524992
+import sys, asyncio
+if sys.version_info[0]==3 and sys.version_info[1] >= 8 and sys.platform.startswith('win'):
+    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
+
+#
+# The timeout we use to assume no more messages are coming
+# from the sever.
+#
+DONE_TIMEOUT = 1.0
+os.environ['ASYNC_TEST_TIMEOUT'] = "20"     # Global test case timeout
+
+MAX_TERMS = 3                               # Testing thresholds
+
+class TestTermClient(object):
+    """Test connection to a terminal manager"""
+    def __init__(self, websocket):
+        self.ws = websocket
+        self.pending_read = None
+
+    @tornado.gen.coroutine
+    def read_msg(self):
+
+        # Because the Tornado Websocket client has no way to cancel
+        # a pending read, we have to keep track of them...
+        if self.pending_read is None:
+            self.pending_read = self.ws.read_message()
+
+        response = yield self.pending_read
+        self.pending_read = None
+        if response:
+            response = json.loads(response)
+        raise tornado.gen.Return(response)
+
+    @tornado.gen.coroutine
+    def read_all_msg(self, timeout=DONE_TIMEOUT):
+        """Read messages until read times out"""
+        msglist = []
+        delta = datetime.timedelta(seconds=timeout)
+        while True:
+            try:
+                mf = self.read_msg()
+                msg = yield tornado.gen.with_timeout(delta, mf)
+            except tornado.gen.TimeoutError:
+                raise tornado.gen.Return(msglist)
+
+            msglist.append(msg)
+
+    def write_msg(self, msg):
+        self.ws.write_message(json.dumps(msg))
+
+    @tornado.gen.coroutine
+    def read_stdout(self, timeout=DONE_TIMEOUT):
+        """Read standard output until timeout read reached,
+           return stdout and any non-stdout msgs received."""
+        msglist = yield self.read_all_msg(timeout)
+        stdout = "".join([msg[1] for msg in msglist if msg[0] == 'stdout'])
+        othermsg = [msg for msg in msglist if msg[0] != 'stdout']
+        raise tornado.gen.Return((stdout, othermsg))
+
+    def write_stdin(self, data):
+        """Write to terminal stdin"""
+        self.write_msg(['stdin', data])
+
+    @tornado.gen.coroutine
+    def get_pid(self):
+        """Get process ID of terminal shell process"""
+        yield self.read_stdout()                          # Clear out any pending
+        self.write_stdin("echo $$\r")
+        (stdout, extra) = yield self.read_stdout()
+        if os.name == 'nt':
+            match = re.search(r'echo \$\$\x1b\[0K\r\n(\d+)', stdout)
+            pid = int(match.groups()[0])
+        else:
+            pid = int(stdout.split('\n')[1])
+        raise tornado.gen.Return(pid)
+
+    def close(self):
+        self.ws.close()
+
+class TermTestCase(tornado.testing.AsyncHTTPTestCase):
+
+    # Factory for TestTermClient, because it has to be a Tornado co-routine.
+    # See:  https://github.com/tornadoweb/tornado/issues/1161
+    @tornado.gen.coroutine
+    def get_term_client(self, path):
+        port = self.get_http_port()
+        url = 'ws://127.0.0.1:%d%s' % (port, path)
+        request = tornado.httpclient.HTTPRequest(url,
+                    headers={'Origin' : 'http://127.0.0.1:%d' % port})
+
+        ws = yield tornado.websocket.websocket_connect(request)
+        raise tornado.gen.Return(TestTermClient(ws))
+
+    @tornado.gen.coroutine
+    def get_term_clients(self, paths):
+        tms = yield [self.get_term_client(path) for path in paths]
+        raise tornado.gen.Return(tms)
+
+    @tornado.gen.coroutine
+    def get_pids(self, tm_list):
+        pids = []
+        for tm in tm_list:                  # Must be sequential, in case terms are shared
+            pid = yield tm.get_pid()
+            pids.append(pid)
+
+        raise tornado.gen.Return(pids)
+
+    def tearDown(self):
+        self.named_tm.kill_all()
+        self.single_tm.kill_all()
+        self.unique_tm.kill_all()
+        super().tearDown()
+
+    def get_app(self):
+        self.named_tm = NamedTermManager(shell_command=['bash'], 
+                                            max_terminals=MAX_TERMS,
+                                            ioloop=self.io_loop)
+        self.single_tm = SingleTermManager(shell_command=['bash'], 
+                                            ioloop=self.io_loop)
+        self.unique_tm = UniqueTermManager(shell_command=['bash'], 
+                                            max_terminals=MAX_TERMS,
+                                            ioloop=self.io_loop)
+        
+        named_tm = self.named_tm
+        class NewTerminalHandler(tornado.web.RequestHandler):
+            """Create a new named terminal, return redirect"""
+            def get(self):
+                name, terminal = named_tm.new_named_terminal()
+                self.redirect("/named/" + name, permanent=False)
+
+        return tornado.web.Application([
+                    (r"/new",         NewTerminalHandler),
+                    (r"/named/(\w+)", TermSocket, {'term_manager': self.named_tm}),
+                    (r"/single",      TermSocket, {'term_manager': self.single_tm}),
+                    (r"/unique",      TermSocket, {'term_manager': self.unique_tm})
+                ], debug=True)
+
+    test_urls = ('/named/term1', '/unique', '/single')
+
+class CommonTests(TermTestCase):
+    @tornado.testing.gen_test
+    def test_basic(self):
+        for url in self.test_urls:
+            tm = yield self.get_term_client(url)
+            response = yield tm.read_msg()                    
+            self.assertEqual(response, ['setup', {}])
+
+            # Check for initial shell prompt
+            response = yield tm.read_msg()
+            self.assertEqual(response[0], 'stdout')
+            self.assertGreater(len(response[1]), 0)
+            tm.close()        
+
+    @tornado.testing.gen_test
+    def test_basic_command(self):
+        for url in self.test_urls:
+            tm = yield self.get_term_client(url)
+            yield tm.read_all_msg()
+            tm.write_stdin("whoami\n")
+            (stdout, other) = yield tm.read_stdout()
+            if os.name == 'nt':
+                assert 'whoami' in stdout
+            else:
+                assert stdout.startswith('who')
+            assert other == []
+            tm.close()
+
+class NamedTermTests(TermTestCase):
+    def test_new(self):
+        response = self.fetch("/new", follow_redirects=False)
+        self.assertEqual(response.code, 302)
+        url = response.headers["Location"]
+
+        # Check that the new terminal was created
+        name = url.split('/')[2]
+        self.assertIn(name, self.named_tm.terminals)
+
+    @tornado.testing.gen_test
+    def test_namespace(self):
+        names = ["/named/1"]*2 + ["/named/2"]*2
+        tms = yield self.get_term_clients(names)
+        pids = yield self.get_pids(tms)
+
+        self.assertEqual(pids[0], pids[1])
+        self.assertEqual(pids[2], pids[3])
+        self.assertNotEqual(pids[0], pids[3])
+
+    @tornado.testing.gen_test
+    def test_max_terminals(self):
+        urls = ["/named/%d" % i for i in range(MAX_TERMS+1)]
+        tms = yield self.get_term_clients(urls[:MAX_TERMS])
+        pids = yield self.get_pids(tms)
+
+        # MAX_TERMS+1 should fail
+        tm = yield self.get_term_client(urls[MAX_TERMS])
+        msg = yield tm.read_msg()
+        self.assertEqual(msg, None)             # Connection closed
+
+class SingleTermTests(TermTestCase):
+    @tornado.testing.gen_test
+    def test_single_process(self):
+        tms = yield self.get_term_clients(["/single", "/single"])
+        pids = yield self.get_pids(tms)
+        self.assertEqual(pids[0], pids[1])
+
+class UniqueTermTests(TermTestCase):
+    @tornado.testing.gen_test
+    def test_unique_processes(self):
+        tms = yield self.get_term_clients(["/unique", "/unique"])
+        pids = yield self.get_pids(tms)
+        self.assertNotEqual(pids[0], pids[1])
+
+    @tornado.testing.gen_test
+    def test_max_terminals(self):
+        tms = yield self.get_term_clients(['/unique'] * MAX_TERMS)
+        pids = yield self.get_pids(tms)
+        self.assertEqual(len(set(pids)), MAX_TERMS)        # All PIDs unique
+
+        # MAX_TERMS+1 should fail
+        tm = yield self.get_term_client("/unique")
+        msg = yield tm.read_msg()
+        self.assertEqual(msg, None)             # Connection closed
+
+        # Close one
+        tms[0].close()
+        msg = yield tms[0].read_msg()           # Closed
+        self.assertEquals(msg, None)
+
+        # Should be able to open back up to MAX_TERMS
+        tm = yield self.get_term_client("/unique")
+        msg = yield tm.read_msg()
+        self.assertEquals(msg[0], 'setup')
+
+if __name__ == '__main__':
+    unittest.main()

venv/Lib/site-packages/terminado/uimodule.py

@@ -0,0 +1,27 @@
+"""A Tornado UI module for a terminal backed by terminado.
+
+See the Tornado docs for information on UI modules:
+http://www.tornadoweb.org/en/stable/guide/templates.html#ui-modules
+"""
+# Copyright (c) Jupyter Development Team
+# Copyright (c) 2014, Ramalingam Saravanan <sarava@sarava.net>
+# Distributed under the terms of the Simplified BSD License.
+
+import os.path
+import tornado.web
+
+class Terminal(tornado.web.UIModule):
+    def render(self, ws_url, cols=80, rows=25):
+        return ('<div class="terminado-container" '
+                'data-ws-url="{ws_url}" '
+                'data-rows="{rows}" data-cols="{cols}"/>').format(
+                        ws_url=ws_url, rows=rows, cols=cols)
+
+    def javascript_files(self):
+        # TODO: Can we calculate these dynamically?
+        return ['/xstatic/termjs/term.js', '/static/terminado.js']
+
+    def embedded_javascript(self):
+        file = os.path.join(os.path.dirname(__file__), 'uimod_embed.js')
+        with open(file) as f:
+            return f.read()

venv/Lib/site-packages/terminado/websocket.py

@@ -0,0 +1,112 @@
+"""Tornado websocket handler to serve a terminal interface.
+"""
+# Copyright (c) Jupyter Development Team
+# Copyright (c) 2014, Ramalingam Saravanan <sarava@sarava.net>
+# Distributed under the terms of the Simplified BSD License.
+
+from __future__ import absolute_import, print_function
+
+# Python3-friendly imports
+try:
+    from urllib.parse import urlparse
+except ImportError:
+    from urlparse import urlparse
+
+import json
+import logging
+
+import tornado.web
+import tornado.websocket
+
+
+def _cast_unicode(s):
+    if isinstance(s, bytes):
+        return s.decode('utf-8')
+    return s
+
+
+class TermSocket(tornado.websocket.WebSocketHandler):
+    """Handler for a terminal websocket"""
+
+    def initialize(self, term_manager):
+        self.term_manager = term_manager
+        self.term_name = ""
+        self.size = (None, None)
+        self.terminal = None
+
+        self._logger = logging.getLogger(__name__)
+
+    def origin_check(self, origin=None):
+        """Deprecated: backward-compat for terminado <= 0.5."""
+        return self.check_origin(origin or self.request.headers.get('Origin'))
+
+    def open(self, url_component=None):
+        """Websocket connection opened.
+
+        Call our terminal manager to get a terminal, and connect to it as a
+        client.
+        """
+        # Jupyter has a mixin to ping websockets and keep connections through
+        # proxies alive. Call super() to allow that to set up:
+        super(TermSocket, self).open(url_component)
+
+        self._logger.info("TermSocket.open: %s", url_component)
+
+        url_component = _cast_unicode(url_component)
+        self.term_name = url_component or 'tty'
+        self.terminal = self.term_manager.get_terminal(url_component)
+        self.terminal.clients.append(self)
+        self.send_json_message(["setup", {}])
+        self._logger.info("TermSocket.open: Opened %s", self.term_name)
+        # Now drain the preopen buffer, if it exists.
+        buffered = ""
+        while True:
+            if not self.terminal.preopen_buffer:
+                break
+            s = self.terminal.preopen_buffer.popleft()
+            buffered += s
+        if buffered:
+            self.on_pty_read(buffered)
+
+    def on_pty_read(self, text):
+        """Data read from pty; send to frontend"""
+        self.send_json_message(['stdout', text])
+
+    def send_json_message(self, content):
+        json_msg = json.dumps(content)
+        self.write_message(json_msg)
+
+    def on_message(self, message):
+        """Handle incoming websocket message
+
+        We send JSON arrays, where the first element is a string indicating
+        what kind of message this is. Data associated with the message follows.
+        """
+        ##logging.info("TermSocket.on_message: %s - (%s) %s", self.term_name, type(message), len(message) if isinstance(message, bytes) else message[:250])
+        command = json.loads(message)
+        msg_type = command[0]
+
+        if msg_type == "stdin":
+            self.terminal.ptyproc.write(command[1])
+        elif msg_type == "set_size":
+            self.size = command[1:3]
+            self.terminal.resize_to_smallest()
+
+    def on_close(self):
+        """Handle websocket closing.
+
+        Disconnect from our terminal, and tell the terminal manager we're
+        disconnecting.
+        """
+        self._logger.info("Websocket closed")
+        if self.terminal:
+            self.terminal.clients.remove(self)
+            self.terminal.resize_to_smallest()
+        self.term_manager.client_disconnected(self)
+
+    def on_pty_died(self):
+        """Terminal closed: tell the frontend, and close the socket.
+        """
+        self.send_json_message(['disconnect', 1])
+        self.close()
+        self.terminal = None