aiomonitor-ng 0.7.2
aiomonitor-ng adds monitor and python REPL capabilities for asyncio application
License: Apache 2

aiomonitor-ng
=============

**aiomonitor-ng** is a (temporary) fork of **aiomonitor** with support for
Python 3.10+ and additional usability & debuggability improvements.

**aiomonitor** is a module that adds monitor and cli capabilities
for asyncio_ applications. Idea and code were borrowed from curio_ project.
Task monitor that runs concurrently to the asyncio_ loop (or fast drop-in
replacement uvloop_) in a separate thread as result monitor will work even if
the event loop is blocked for some reason.

This library provides a python console using aioconsole_ module. It is possible
to execute asynchronous commands inside your running application. Extensible
with you own commands, in the style of the standard library's cmd_ module

.. image:: https://raw.githubusercontent.com/achimnol/aiomonitor-ng/master/docs/screenshot-ps-where-example.png

Installation
------------
Installation process is simple, just::

    $ pip install aiomonitor-ng


Example
-------
Monitor has context manager interface:

.. code:: python

    import aiomonitor

    async def main():
        loop = asyncio.get_running_loop()
        run_forever = loop.create_future()
        with aiomonitor.start_monitor(loop):
            await run_forever

    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        pass

Now from separate terminal it is possible to connect to the application::

    $ telnet localhost 50101

or the included python client::

    $ python -m aiomonitor.cli
    
    
Tutorial
--------

Let's create a simple aiohttp_ application, and see how ``aiomonitor`` can
be integrated with it.

.. code:: python

    import asyncio

    import aiomonitor
    from aiohttp import web

    # Simple handler that returns response after 100s
    async def simple(request):
        loop = request.app.loop

        print('Start sleeping')
        await asyncio.sleep(100, loop=loop)
        return web.Response(text="Simple answer")

    loop = asyncio.get_event_loop()
    # create application and register route
    app = web.Application(loop=loop)
    app.router.add_get('/simple', simple)

    # it is possible to pass a dictionary with local variables
    # to the python console environment
    host, port = "localhost", 8090
    locals_ = {"port": port, "host": host}
    # init monitor just before run_app
    with aiomonitor.start_monitor(loop=loop, locals=locals_):
        # run application with built-in aiohttp run_app function
        web.run_app(app, port=port, host=host)

Let's save this code in file ``simple_srv.py``, so we can run it with the following command::

    $ python simple_srv.py
    ======== Running on http://localhost:8090 ========
    (Press CTRL+C to quit)

And now one can connect to a running application from a separate terminal, with
the ``telnet`` command, and ``aiomonitor`` will immediately respond with prompt::

    $ telnet localhost 50101
    Asyncio Monitor: 1 tasks running
    Type help for commands
    monitor >>>

Now you can type commands, for instance, ``help``::

    monitor >>> help
    Usage: help [OPTIONS] COMMAND [ARGS]...
    
      To see the usage of each command, run them with "--help" option.
    
    Commands:
      cancel                  Cancel an indicated task
      console                 Switch to async Python REPL
      exit (q,quit)           Leave the monitor client session
      help (?,h)              Show the list of commands
      ps (p)                  Show task table
      ps-terminated (pst,pt)  List recently terminated/cancelled tasks
      signal                  Send a Unix signal
      stacktrace (st,stack)   Print a stack trace from the event loop thread
      where (w)               Show stack frames and the task creation chain of a task
      where-terminated (wt)   Show stack frames and the termination/cancellation chain of a task

``aiomonitor`` also supports async python console inside a running event loop
so you can explore the state of your application::

    monitor >>> console
    Python 3.10.7 (main, Sep  9 2022, 12:31:20) [Clang 13.1.6 (clang-1316.0.21.2.5)] on darwin
    Type "help", "copyright", "credits" or "license" for more information.
    ---
    This console is running in an asyncio event loop.
    It allows you to wait for coroutines using the 'await' syntax.
    Try: await asyncio.sleep(1, result=3)
    ---
    >>> await asyncio.sleep(1, result=3)
    3
    >>>

To leave the console type ``exit()`` or press Ctrl+D::

    >>> exit()

    ✓ The console session is closed.
    monitor >>>

Extension
---------

Additional console variables
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You may add more variables that can be directly referenced in the ``console`` command.
Refer `the console-variables example code <https://github.com/achimnol/aiomonitor-ng/tree/master/examples/console-variables.py>`_

Custom console commands
~~~~~~~~~~~~~~~~~~~~~~~

``aiomonitor`` is very easy to extend with your own console commands.
Refer `the extension example code <https://github.com/achimnol/aiomonitor-ng/tree/master/examples/extension.py>`_

Requirements
------------

* Python_ 3.8+ (3.10.7+ recommended)
* aioconsole_
* Click_
* prompt_toolkit_
* uvloop_ (optional)


.. _PEP492: https://www.python.org/dev/peps/pep-0492/
.. _Python: https://www.python.org
.. _aioconsole: https://github.com/vxgmichel/aioconsole
.. _aiohttp: https://github.com/aio-libs/aiohttp
.. _asyncio: http://docs.python.org/3/library/asyncio.html
.. _Click: https://click.palletsprojects.com
.. _curio: https://github.com/dabeaz/curio
.. _prompt_toolkit: https://python-prompt-toolkit.readthedocs.io
.. _uvloop: https://github.com/MagicStack/uvloop
.. _cmd: http://docs.python.org/3/library/cmd.html

CHANGES
=======

0.7.1 (2023-04-16)
------------------

* Support Python 3.11 properly by allowing the optional `name` and `context` kwargs passed to `asyncio.create_task()` in the hooked task factory function (#10)

* Update development dependencies


0.7.0 (2022-10-19)
------------------

* Selective persistent termination logs (#9)

* Implement cancellation chain tracker (#8)

* Trigger auto-completion only when Tab is pressed

* Support auto-completion of commands and arguments (#7)

* Add missing explicit dependency to Click


0.6.0 (2022-09-26)
------------------

* Promote `console_locals` as public attr

* Reimplement console command (#6)

* Migrate to Click-based command line interface (#5)

* Adopt `prompt_toolkit` and support concurrent clients (#4)

* Show the total number of tasks when executing `ps` (#3)

* Apply black, isort, mypy, flake8 and automate CI workflows using GitHub Actions


0.5.1 (2022-08-29)
------------------

* Fix the task creation location in the 'ps' command output


0.5.0 (2022-08-26)
------------------

* Made it compatible with Python 3.10

* Added the task creation stack chain display to the 'where' command by setting a custom task factory (#1)

* Changed the 'ps' command view to be more concise and display many tasks in a better way (#2)


0.4.5 (2019-11-03)
------------------

* Fixed endless loop on EOF (thanks @apatrushev)


0.4.4 (2019-03-23)
------------------

* Simplified python console start end #175

* Added python 3.7 compatibility #176


0.4.3 (2019-02-02)
------------------

* Reworked console server start/close logic #169


0.4.2 (2019-01-13)
------------------

* Fixed issue with type annotations from 0.4.1 release #164


0.4.1 (2019-01-10)
------------------

* Fixed Python 3.5 support #161 (thanks @bmerry)


0.4.0 (2019-01-04)
------------------

* Added support for custom commands #133 (thanks @yggdr)

* Fixed OptLocals being passed as the default value for "locals" #122 (thanks @agronholm)

* Added an API inspired by the standard library's cmd module #135 (thanks @yggdr)

* Correctly report the port running aioconsole #124 (thanks @bmerry)


0.3.1 (2018-07-03)
------------------

* Added the stacktrace command #120 (thanks @agronholm)


0.3.0 (2017-09-08)
------------------

* Added _locals_ parameter for passing environment to python REPL


0.2.1 (2016-01-03)
------------------

* Fixed import in telnet cli in #12 (thanks @hellysmile)


0.2.0 (2016-01-01)
------------------

* Added basic documentation

* Most of methods of Monitor class are not not private api


0.1.0 (2016-12-14)
------------------

* Added missed LICENSE file

* Updated API, added start_monitor() function


0.0.3 (2016-12-11)
------------------

* Fixed README.rst


0.0.2 (2016-12-11)
------------------

* Tests more stable now

* Added simple tutorial to README.rst


0.0.1 (2016-12-10)
------------------

* Initial release.