On Fri, Aug 6, 2021 at 12:41 AM John Snow <js...@redhat.com> wrote:
>
>
> On Fri, Jul 30, 2021 at 4:19 PM G S Niteesh Babu <niteesh...@gmail.com>
> wrote:
>
>> Added a draft of AQMP TUI.
>>
>> Implements the follwing basic features:
>> 1) Command transmission/reception.
>> 2) Shows events asynchronously.
>> 3) Shows server status in the bottom status bar.
>>
>> Also added necessary pylint, mypy configurations
>>
>> Signed-off-by: G S Niteesh Babu <niteesh...@gmail.com>
>> ---
>> python/qemu/aqmp/aqmp_tui.py | 333 +++++++++++++++++++++++++++++++++++
>> python/setup.cfg | 16 +-
>> 2 files changed, 348 insertions(+), 1 deletion(-)
>> create mode 100644 python/qemu/aqmp/aqmp_tui.py
>>
>> diff --git a/python/qemu/aqmp/aqmp_tui.py b/python/qemu/aqmp/aqmp_tui.py
>> new file mode 100644
>> index 0000000000..ec9eba0aa7
>> --- /dev/null
>> +++ b/python/qemu/aqmp/aqmp_tui.py
>> @@ -0,0 +1,333 @@
>> +# Copyright (c) 2021
>> +#
>> +# Authors:
>> +# Niteesh Babu G S <niteesh...@gmail.com>
>> +#
>> +# This work is licensed under the terms of the GNU GPL, version 2 or
>> +# later. See the COPYING file in the top-level directory.
>> +
>> +import argparse
>> +import asyncio
>> +import logging
>> +from logging import Handler
>> +import signal
>> +
>> +import urwid
>> +import urwid_readline
>> +
>> +from ..qmp import QEMUMonitorProtocol, QMPBadPortError
>> +from .message import DeserializationError, Message, UnexpectedTypeError
>> +from .protocol import ConnectError
>> +from .qmp_client import ExecInterruptedError, QMPClient
>> +from .util import create_task, pretty_traceback
>> +
>> +
>> +UPDATE_MSG = 'UPDATE_MSG'
>> +
>> +# Using root logger to enable all loggers under qemu and asyncio
>> +LOGGER = logging.getLogger()
>> +
>> +
>> +def format_json(msg):
>> + """
>> + Formats given multiline JSON message into a single line message.
>> + Converting into single line is more asthetically pleasing when
>> looking
>> + along with error messages compared to multiline JSON.
>> + """
>> + # FIXME: Use better formatting mechanism. Might break at more
>> complex JSON
>> + # data.
>> + msg = msg.replace('\n', '')
>> + words = msg.split(' ')
>> + words = [word for word in words if word != '']
>> + return ' '.join(words)
>> +
>> +
>> +class App(QMPClient):
>> + def __init__(self, address):
>> + urwid.register_signal(type(self), UPDATE_MSG)
>> + self.window = Window(self)
>> + self.address = address
>> + self.aloop = None
>> + super().__init__()
>> +
>> + def add_to_history(self, msg):
>> + urwid.emit_signal(self, UPDATE_MSG, msg)
>> +
>> + def _cb_outbound(self, msg):
>> + # FIXME: I think the ideal way to omit these messages during
>> in-TUI
>> + # logging will be to add a filter to the logger. We can use
>> regex to
>> + # filter out messages starting with 'Request:' or 'Response:'
>> but I
>> + # think a better approach will be encapsulate the message in an
>> object
>> + # and filter based on the object. Encapsulation of the message
>> will
>> + # also be necessary when we want different formatting of messages
>> + # inside TUI.
>> + handler = LOGGER.handlers[0]
>> + if not isinstance(handler, TUILogHandler):
>> + LOGGER.debug('Request: %s', str(msg))
>> + self.add_to_history('<-- ' + str(msg))
>> + return msg
>> +
>> + def _cb_inbound(self, msg):
>> + handler = LOGGER.handlers[0]
>> + if not isinstance(handler, TUILogHandler):
>> + LOGGER.debug('Response: %s', str(msg))
>> + self.add_to_history('--> ' + str(msg))
>> + return msg
>> +
>> + async def wait_for_events(self):
>> + async for event in self.events:
>> + self.handle_event(event)
>> +
>> + async def _send_to_server(self, raw_msg):
>> + # FIXME: Format the raw_msg in history view to one line. It is
>> not
>> + # pleasing to see multiple lines JSON object with an error
>> statement.
>> + try:
>> + msg = Message(bytes(raw_msg, encoding='utf-8'))
>> + # Format multiline json into a single line JSON, since it is
>> more
>> + # pleasing to look along with err message in TUI.
>> + raw_msg = self.format_json(raw_msg)
>> + await self._raw(msg, assign_id='id' not in msg)
>> + except (ValueError, TypeError) as err:
>> + LOGGER.info('Invalid message: %s', str(err))
>> + self.add_to_history(f'{raw_msg}: {err}')
>> + except (DeserializationError, UnexpectedTypeError) as err:
>> + LOGGER.info('Invalid message: %s', err.error_message)
>> + self.add_to_history(f'{raw_msg}: {err.error_message}')
>> + except ExecInterruptedError:
>> + LOGGER.info('Error server disconnected before reply')
>> + urwid.emit_signal(self, UPDATE_MSG,
>> + '{"error": "Server disconnected before
>> reply"}')
>> + self._set_status("Server disconnected")
>> + except Exception as err:
>> + LOGGER.error('Exception from _send_to_server: %s', str(err))
>> + raise err
>> +
>> + def cb_send_to_server(self, msg):
>> + create_task(self._send_to_server(msg))
>> +
>> + def unhandled_input(self, key):
>> + if key == 'esc':
>> + self.kill_app()
>> +
>> + def kill_app(self):
>> + # TODO: Work on the disconnect logic
>> + create_task(self._kill_app())
>> +
>> + async def _kill_app(self):
>> + # It is ok to call disconnect even in disconnect state
>> + try:
>> + await self.disconnect()
>> + LOGGER.debug('Disconnect finished. Exiting app')
>> + except Exception as err:
>> + LOGGER.info('_kill_app: %s', str(err))
>> + # Let the app crash after providing a proper stack trace
>> + raise err
>> + raise urwid.ExitMainLoop()
>> +
>> + def handle_event(self, event):
>> + # FIXME: Consider all states present in qapi/run-state.json
>> + if event['event'] == 'SHUTDOWN':
>> + self._set_status('Server shutdown')
>> +
>> + def _set_status(self, msg: str) -> None:
>> + self.window.footer.set_text(msg)
>> +
>> + def _get_formatted_address(self) -> str:
>> + addr = f'{self.address}'
>> + if isinstance(self.address, tuple):
>> + host, port = self.address
>> + addr = f'{host}:{port}'
>> + return addr
>> +
>> + async def connect_server(self):
>> + try:
>> + await self.connect(self.address)
>> + addr = self._get_formatted_address()
>> + self._set_status(f'Connected to {addr}')
>> + except ConnectError as err:
>> + LOGGER.info('connect_server: ConnectError %s', str(err))
>> + self._set_status('Server shutdown')
>> +
>> + def run(self, debug=False):
>> + self.aloop = asyncio.get_event_loop()
>> + self.aloop.set_debug(debug)
>> +
>> + # Gracefully handle SIGTERM and SIGINT signals
>> + cancel_signals = [signal.SIGTERM, signal.SIGINT]
>> + for sig in cancel_signals:
>> + self.aloop.add_signal_handler(sig, self.kill_app)
>> +
>> + event_loop = urwid.AsyncioEventLoop(loop=self.aloop)
>> + main_loop = urwid.MainLoop(urwid.AttrMap(self.window,
>> 'background'),
>> + unhandled_input=self.unhandled_input,
>> + handle_mouse=True,
>> + event_loop=event_loop)
>> +
>> + create_task(self.wait_for_events(), self.aloop)
>> + create_task(self.connect_server(), self.aloop)
>> + try:
>> + main_loop.run()
>> + except Exception as err:
>> + LOGGER.error('%s\n%s\n', str(err), pretty_traceback())
>> + raise err
>> +
>> +
>> +class StatusBar(urwid.Text):
>> + """
>> + A simple Text widget that currently only shows connection status.
>> + """
>> + def __init__(self, text=''):
>> + super().__init__(text, align='right')
>> +
>> +
>> +class Editor(urwid_readline.ReadlineEdit):
>> + """
>> + Support urwid_readline features along with
>> + history support which lacks in urwid_readline
>> + """
>> + def __init__(self, master):
>> + super().__init__(caption='> ', multiline=True)
>> + self.master = master
>> + self.history = []
>> + self.last_index = -1
>> + self.show_history = False
>> +
>> + def keypress(self, size, key):
>> + # TODO: Add some logic for down key and clean up logic if
>> possible.
>> + # Returning None means the key has been handled by this widget
>> + # which otherwise is propogated to the parent widget to be
>> + # handled
>> + msg = self.get_edit_text()
>> + if key == 'up' and not msg:
>> + # Show the history when 'up arrow' is pressed with no input
>> text.
>> + # NOTE: The show_history logic is necessary because in
>> 'multiline'
>> + # mode (which we use) 'up arrow' is used to move between
>> lines.
>> + self.show_history = True
>> + last_msg = self.history[self.last_index] if self.history
>> else ''
>> + self.set_edit_text(last_msg)
>> + self.edit_pos = len(last_msg)
>> + self.last_index += 1
>> + elif key == 'up' and self.show_history:
>> + if self.last_index < len(self.history):
>> + self.set_edit_text(self.history[self.last_index])
>> + self.edit_pos = len(self.history[self.last_index])
>> + self.last_index += 1
>> + elif key == 'meta enter':
>> + # When using multiline, enter inserts a new line into the
>> editor
>> + # send the input to the server on alt + enter
>> + self.master.cb_send_to_server(msg)
>>
>
> cb_send_to_server calls create_task(App._send_to_server(msg)) at which
> point in the coroutine you finally do msg = Message(bytes(raw_msg,
> encoding='utf-8')). However, you can do your message conversion *first*,
> here in the Editor.
>
> That way, you can avoid erasing the editor bar when the message is garbled
> and the user has a chance to fix the corrupted message *first* before we
> dispatch to the callback-async-machine. That should reduce quite a lot of
> the error cases in _send_to_server and helps separate out the two kinds of
> errors we expect to see here:
>
> 1. The user typed something that's garbage, and we didn't actually even
> send it (because we couldn't), and
> 2. We sent (or tried to send) the message; but a failure occurred.
>
Thanks. Refactored this.
>
>
>> + self.history.insert(0, msg)
>> + self.set_edit_text('')
>> + self.last_index = 0
>> + self.show_history = False
>> + else:
>> + self.show_history = False
>> + self.last_index = 0
>> + return super().keypress(size, key)
>> + return None
>> +
>> +
>> +class EditorWidget(urwid.Filler):
>> + """
>> + Wraps CustomEdit
>> + """
>> + def __init__(self, master):
>> + super().__init__(Editor(master), valign='top')
>> +
>> +
>> +class HistoryBox(urwid.ListBox):
>> + """
>> + Shows all the QMP message transmitted/received
>> + """
>> + def __init__(self, master):
>> + self.master = master
>> + self.history = urwid.SimpleFocusListWalker([])
>> + super().__init__(self.history)
>> +
>> + def add_to_history(self, history):
>> + self.history.append(urwid.Text(history))
>> + if self.history:
>> + self.history.set_focus(len(self.history) - 1)
>> +
>> +
>> +class HistoryWindow(urwid.Frame):
>> + """
>> + Composes the HistoryBox and EditorWidget
>> + """
>> + def __init__(self, master):
>> + self.master = master
>> + self.editor_widget = EditorWidget(master)
>> + self.editor = urwid.LineBox(self.editor_widget)
>> + self.history = HistoryBox(master)
>> + self.body = urwid.Pile([('weight', 80, self.history),
>> + ('weight', 20, self.editor)])
>> + super().__init__(self.body)
>> + urwid.connect_signal(self.master, UPDATE_MSG,
>> self.cb_add_to_history)
>> +
>> + def cb_add_to_history(self, msg):
>> + self.history.add_to_history(msg)
>> +
>> +
>> +class Window(urwid.Frame):
>> + """
>> + This is going to be the main window that is going to compose other
>> + windows. In this stage it is unnecesssary but will be necessary in
>> + future when we will have multiple windows and want to the switch
>> between
>> + them and display overlays
>> + """
>> + def __init__(self, master):
>> + self.master = master
>> + footer = StatusBar()
>> + body = HistoryWindow(master)
>> + super().__init__(body, footer=footer)
>> +
>> +
>> +class TUILogHandler(Handler):
>> + def __init__(self, tui):
>> + super().__init__()
>> + self.tui = tui
>> +
>> + def emit(self, record):
>> + level = record.levelname
>> + msg = record.getMessage()
>> + msg = f'[{level}]: {msg}'
>> + self.tui.add_to_history(msg)
>> +
>> +
>> +def main():
>> + parser = argparse.ArgumentParser(description='AQMP TUI')
>> + parser.add_argument('qmp_server', help='Address of the QMP server'
>> + '< UNIX socket path | TCP addr:port >')
>> + parser.add_argument('--log-file', help='The Log file name')
>> + parser.add_argument('--log-level', default='WARNING',
>> + help='Log level
>> <CRITICAL|ERROR|WARNING|INFO|DEBUG|>')
>> + parser.add_argument('--asyncio-debug', action='store_true',
>> + help='Enable debug mode for asyncio loop'
>> + 'Generates lot of output, makes TUI unusable
>> when'
>> + 'logs are logged in the TUI itself.'
>> + 'Use only when logging to a file')
>> + args = parser.parse_args()
>> +
>> + try:
>> + address = QEMUMonitorProtocol.parse_address(args.qmp_server)
>> + except QMPBadPortError as err:
>> + parser.error(err)
>> +
>> + app = App(address)
>> +
>> + if args.log_file:
>> + LOGGER.addHandler(logging.FileHandler(args.log_file))
>> + else:
>> + LOGGER.addHandler(TUILogHandler(app))
>> +
>> + log_level = logging.getLevelName(args.log_level)
>> + # getLevelName returns 'Level {log_level}' when a invalid level is
>> passed.
>> + if log_level == f'Level {args.log_level}':
>> + parser.error('Invalid log level')
>> + LOGGER.setLevel(log_level)
>> +
>> + app.run(args.asyncio_debug)
>> +
>> +
>> +if __name__ == '__main__':
>> + main() # type: ignore
>> diff --git a/python/setup.cfg b/python/setup.cfg
>> index d106a0ed7a..50f9894468 100644
>> --- a/python/setup.cfg
>> +++ b/python/setup.cfg
>> @@ -81,8 +81,22 @@ namespace_packages = True
>> # fusepy has no type stubs:
>> allow_subclassing_any = True
>>
>> +[mypy-qemu.aqmp.aqmp_tui]
>> +disallow_untyped_defs = False
>> +disallow_incomplete_defs = False
>> +check_untyped_defs = False
>> +# urwid and urwid_readline have no type stubs:
>> +allow_subclassing_any = True
>> +
>> +# The following missing import directives are because these libraries do
>> not
>> +# provide type stubs. Allow them on an as-needed basis for mypy.
>> [mypy-fuse]
>> -# fusepy has no type stubs:
>> +ignore_missing_imports = True
>> +
>> +[mypy-urwid]
>> +ignore_missing_imports = True
>> +
>> +[mypy-urwid_readline]
>> ignore_missing_imports = True
>>
>> [pylint.messages control]
>> --
>> 2.17.1
>>
>>
