Merge commit '19031b24b523c872c1ac367821dc60c950a09755' as 'modules/libjuju'

[osm/N2VC.git] / modules / libjuju / examples / relate.py

diff --git a/modules/libjuju/examples/relate.py b/modules/libjuju/examples/relate.py
new file mode 100644 (file)
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+++ b/modules/libjuju/examples/relate.py
@@ -0,0 +1,98 @@
+"""
+This example:
+
+1. Connects to the current model
+2. Resets it
+3. Deploys two charms and relates them
+4. Waits for units to be idle, then exits
+
+"""
+import asyncio
+import logging
+
+from juju.model import Model, ModelObserver
+from juju import loop
+
+
+class MyRemoveObserver(ModelObserver):
+    async def on_change(self, delta, old, new, model):
+        if delta.type == 'remove':
+            assert(new.latest() == new)
+            assert(new.next() is None)
+            assert(new.dead)
+            assert(new.current)
+            assert(new.connected)
+            assert(new.previous().dead)
+            assert(not new.previous().current)
+            assert(not new.previous().connected)
+
+
+class MyModelObserver(ModelObserver):
+    _shutting_down = False
+
+    async def on_change(self, delta, old, new, model):
+        if model.units and model.all_units_idle() and not self._shutting_down:
+            self._shutting_down = True
+            logging.debug('All units idle, disconnecting')
+            await model.reset(force=True)
+            await model.disconnect()
+
+
+async def main():
+    model = Model()
+    await model.connect_current()
+
+    model.add_observer(MyRemoveObserver())
+    await model.reset(force=True)
+    model.add_observer(MyModelObserver())
+
+    ubuntu_app = await model.deploy(
+        'ubuntu',
+        application_name='ubuntu',
+        series='trusty',
+        channel='stable',
+    )
+    ubuntu_app.on_change(asyncio.coroutine(
+        lambda delta, old_app, new_app, model:
+            print('App changed: {}'.format(new_app.entity_id))
+    ))
+    ubuntu_app.on_remove(asyncio.coroutine(
+        lambda delta, old_app, new_app, model:
+            print('App removed: {}'.format(old_app.entity_id))
+    ))
+    ubuntu_app.on_unit_add(asyncio.coroutine(
+        lambda delta, old_unit, new_unit, model:
+            print('Unit added: {}'.format(new_unit.entity_id))
+    ))
+    ubuntu_app.on_unit_remove(asyncio.coroutine(
+        lambda delta, old_unit, new_unit, model:
+            print('Unit removed: {}'.format(old_unit.entity_id))
+    ))
+    unit_a, unit_b = await ubuntu_app.add_units(count=2)
+    unit_a.on_change(asyncio.coroutine(
+        lambda delta, old_unit, new_unit, model:
+            print('Unit changed: {}'.format(new_unit.entity_id))
+    ))
+    await model.deploy(
+        'nrpe',
+        application_name='nrpe',
+        series='trusty',
+        channel='stable',
+        # subordinates must be deployed without units
+        num_units=0,
+    )
+    my_relation = await model.add_relation(
+        'ubuntu',
+        'nrpe',
+    )
+    my_relation.on_remove(asyncio.coroutine(
+        lambda delta, old_rel, new_rel, model:
+            print('Relation removed: {}'.format(old_rel.endpoints))
+    ))
+
+
+if __name__ == '__main__':
+    logging.basicConfig(level=logging.DEBUG)
+    ws_logger = logging.getLogger('websockets.protocol')
+    ws_logger.setLevel(logging.INFO)
+    loop.run(main())