A Python library for Juju

Source code: https://github.com/juju/python-libjuju

Bug reports: https://github.com/juju/python-libjuju/issues

Documentation: https://pythonlibjuju.readthedocs.io/en/latest/

Design Notes

• Asynchronous - Uses asyncio and async/await features of Python
• Websocket-level bindings are programmatically generated (indirectly) from the Juju golang code, ensuring full api coverage
• Provides an OO layer which encapsulates much of the websocket api and provides familiar nouns and verbs (e.g. Model.deploy(), Application.add_unit(), etc.)

Installation

.. code:: bash

pip3 install juju

Quickstart

Here's a simple example that shows basic usage of the library. The example connects to the currently active Juju model, deploys a single unit of the ubuntu charm, then exits:

Note : Pylibjuju requires an already bootstrapped Juju controller to connect to.

.. code:: python

!/usr/bin/python3

import asyncio import logging import sys

from juju.model import Model

async def deploy():

Create a Model instance. We need to connect our Model to a Juju api

  # server before we can use it.
  model = Model()

  # Connect to the currently active Juju model
  await model.connect()

  try:
      # Deploy a single unit of the ubuntu charm, using the latest revision
      # from the stable channel of the Charm Store.
      ubuntu_app = await model.deploy(
        'ubuntu',
        application_name='my-ubuntu',
      )

      if '--wait' in sys.argv:
          # optionally block until the application is ready
          await model.wait_for_idle(status='active')

  finally:
      # Disconnect from the api server and cleanup.
      await model.disconnect()

def main(): logging.basicConfig(level=logging.INFO)

  # If you want to see everything sent over the wire, set this to DEBUG.
  ws_logger = logging.getLogger('websockets.protocol')
  ws_logger.setLevel(logging.INFO)

  # Run the deploy coroutine in an asyncio event loop, using a helper
  # that abstracts loop creation and teardown.
  asyncio.run(deploy())

if name == 'main': main()

More examples can be found in the docs, as well as in the examples/ directory of the source tree which can be run using tox. For example, to run examples/connect_current_model.py, use:

.. code:: bash

tox -e example -- examples/connect_current_model.py

REPL ^^^^

To experiment with the library in a REPL, launch python in asyncio mode

.. code:: bash

$ python3 -m asyncio

and then, to connect to the current model and fetch status:

.. code::

from juju.model import Model model = Model() await model.connect_current() status = await model.get_status()

Versioning

The current Pylibjuju release policy tracks the Juju release cadence. In particular, whenever Juju makes a latest/stable release, pylibjuju pushes out a release with the same version in the following week. Newly generated schemas will be updated per Juju releases.