examples/relate.py

   1 """
   2 This example:
   3
   4 1. Connects to the current model
   5 2. Resets it
   6 3. Deploys two charms and relates them
   7 4. Waits for units to be idle, then exits
   8
   9 """
  10 import asyncio
  11 import logging
  12
  13 from juju.model import Model, ModelObserver
  14
  15
  16 class MyRemoveObserver(ModelObserver):
  17     async def on_change(self, delta, old, new, model):
  18         if delta.type == 'remove':
  19             assert(new.latest() == new)
  20             assert(new.next() is None)
  21             assert(new.dead)
  22             assert(new.current)
  23             assert(new.connected)
  24             assert(new.previous().dead)
  25             assert(not new.previous().current)
  26             assert(not new.previous().connected)
  27
  28
  29 class MyModelObserver(ModelObserver):
  30     async def on_change(self, delta, old, new, model):
  31         if model.all_units_idle():
  32             logging.debug('All units idle, disconnecting')
  33             await model.disconnect()
  34             model.loop.stop()
  35
  36
  37 async def run():
  38     model = Model()
  39     await model.connect_current()
  40
  41     model.add_observer(MyRemoveObserver())
  42     await model.reset(force=True)
  43     model.add_observer(MyModelObserver())
  44
  45     await model.deploy(
  46         'ubuntu-0',
  47         service_name='ubuntu',
  48         series='trusty',
  49         channel='stable',
  50     )
  51     await model.deploy(
  52         'nrpe-11',
  53         service_name='nrpe',
  54         series='trusty',
  55         channel='stable',
  56         num_units=0,
  57     )
  58     await model.add_relation(
  59         'ubuntu',
  60         'nrpe',
  61     )
  62
  63 logging.basicConfig(level=logging.DEBUG)
  64 ws_logger = logging.getLogger('websockets.protocol')
  65 ws_logger.setLevel(logging.INFO)
  66 loop = asyncio.get_event_loop()
  67 loop.set_debug(False)
  68 loop.create_task(run())
  69 loop.run_forever()