Skip to main content

aiomonitor adds monitor and python REPL capabilities for asyncio application

Project description

aiomonitor

https://travis-ci.org/aio-libs/aiomonitor.svg?branch=master https://codecov.io/gh/aio-libs/aiomonitor/branch/master/graph/badge.svg

aiomonitor is Python 3.5+ module that adds monitor and cli capabilities for asyncio application. Idea and code borrowed from curio project. Task monitor that runs concurrently to the asyncio loop (or fast drop in replacement uvloop) in a separate thread. This can inspect the loop and provide debugging capabilities.

Library provides an python console using aioconsole module, it is possible to execute asynchronous command inside your running application.

https://raw.githubusercontent.com/aio-libs/aiomonitor/master/docs/tty.gif

Installation

Installation process is simple, just:

$ pip install aiomonitor

Example

Monitor has context manager interface:

import aiomonitor

loop = asyncio.get_event_loop()
with aiomonitor.start_monitor(loop=loop):
    loop.run_forever()

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

$ nc localhost 50101

or using included python client:

$ python -m aiomonitor.cli

Tutorial

Lets create simple aiohttp application, and see how aiomonitor can integrates with it.

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 create route
app = web.Application(loop=loop)
app.router.add_get('/simple', simple)

# init monitor just before run_app
with aiomonitor.start_monitor(loop=loop):
    # run application with built in aiohttp run_app function
    web.run_app(app, port=8090, host='localhost')

Lets save this code in file simple_srv.py, so we can run it with command:

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

And now one can connect running application from separate terminal, with nc command, immediately aiomonitor will respond with prompt:

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

Now you can type commands, for instance help:

monitor >>> help
Commands:
             ps               : Show task table
             where taskid     : Show stack frames for a task
             cancel taskid    : Cancel an indicated task
             signal signame   : Send a Unix signal
             console          : Switch to async Python REPL
             quit             : Leave the monitor

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

monitor >>> console
Python 3.5.2 (default, Oct 11 2016, 05:05:28)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.38)] 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, loop=loop)
---
>>> await asyncio.sleep(1, result=3, loop=loop)

To leave console type exit():

>>> exit()
monitor >>>

Requirements

CHANGES

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.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

aiomonitor-0.2.0.tar.gz (12.8 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page