implant 0.1.0

Remote execution via stdin/stdout messaging.

implant
**********

.. inclusion-marker-do-not-remove

.. image:: https://travis-ci.org/diefans/implant.svg?branch=master
:target: https://travis-ci.org/diefans/implant

A proof-of-concept for asynchronous adhoc remote procedure calls in Python.

This is work in progress and serves basically as an exercise.


Features
========

- Python >= 3.5 asyncio

- adhoc transferable remote procedures

- remote part of a :py:obj:`implat.core.Command` may reside in a separate module

- a :py:obj:`implant.core.Command` specific :py:obj:`implant.core.Channel`
enables arbitrary protocols between local and remote side

- events

- quite small core

- tests


Limitations
===========

- Python >= 3.5

- only pure Python modules are supported for remote import, if no venv is used

- :py:obj:`implant.core.Command` s must reside in a module other then `__main__`

- at the moment sudo must not ask for password



Example
=======


General application
-------------------

.. code:: python

import asyncio
import pathlib

from implant import core, connect, commands


async def remote_tasks():
# create a connector for a python process
connector = connect.Lxd(
container='zesty',
hostname='localhost'
)
connector_args = {
'python_bin': pathlib.Path('/usr/bin/python3')
}
# connect to a remote python process
remote = await connector.launch(**connector_args)

# start remote communication tasks
com_remote = asyncio.ensure_future(remote.communicate())
try:
# execute command
cmd = commands.SystemLoad()
result = await remote.execute(cmd)

print("Remote system load:", result)

finally:
# stop communication tasks
com_remote.cancel()
await com_remote


if __name__ == '__main__':
loop = asyncio.get_event_loop()
loop.run_until_complete(remote_tasks())
loop.close()


An example Echo Command
-----------------------

.. code:: python

import logging
import os

from implant import core


log = logging.getLogger(__name__)


class Echo(core.Command):

"""Demonstrate the basic command API."""

async def local(self, context):
"""The local side of the RPC.

:param context: :py:obj:`implant.core.DispatchLocalContext`
"""
# custom protocol
# first: send
await context.channel.send_iteration("send to remote")

# second: receive
from_remote = []
async for x in context.channel:
from_remote.append(x)
log.debug("************ receiving from remote: %s", from_remote)

# third: wait for remote to finish and return result
remote_result = await context.remote_future

result = {
'from_remote': ''.join(from_remote),
}
result.update(remote_result)
return result

async def remote(self, context):
"""The remote side of the RPC.

:param context: :py:obj:`implant.core.DispatchRemoteContext`
"""
# first: receive
from_local = []
async for x in context.channel:
from_local.append(x)
log.debug("************ receiving from local: %s", from_local)

# second: send
await context.channel.send_iteration("send to local")

# third: return result
return {
'from_local': ''.join(from_local),
'remote_self': self,
'pid': os.getpid()
}


Internals
=========

::

master <-----------------------------------------> remote
|
stdin/stdout
|
chunks
|
channels
|
--> send ---> | | --> queue -->
| module:class/fqin |
<-- queue <-- | | <--- send <--