Fix bug 1467
Do not raise exceptions in n2vc.libjuju.add_model() or n2vc.libjuju.destroy_model() functions
In general, functions should be as idempotent as possible. In this
particular case, executing the add_model() function several times with
the same arguments should just work. Same thing for destroy_model(). If
the model has already been destroyed, it should return and not give any
errors saying that the model doesn't exist.
Change-Id: I87e11ea0fe1b4063b2f89900fcc2bbf1f915b953
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/n2vc/libjuju.py b/n2vc/libjuju.py
index bf356f4..161370b 100644
--- a/n2vc/libjuju.py
+++ b/n2vc/libjuju.py
@@ -40,7 +40,6 @@
JujuApplicationNotFound,
JujuLeaderUnitNotFound,
JujuActionNotFound,
- JujuModelAlreadyExists,
JujuControllerFailedConnecting,
JujuApplicationExists,
JujuInvalidK8sConfiguration,
@@ -109,7 +108,6 @@
self.loop.set_exception_handler(self.handle_exception)
self.creating_model = asyncio.Lock(loop=self.loop)
- self.models = set()
self.log.debug("Libjuju initialized!")
self.health_check_task = self._create_health_check_task()
@@ -187,22 +185,14 @@
controller = await self.get_controller()
model = None
try:
- # Raise exception if model already exists
- if await self.model_exists(model_name, controller=controller):
- raise JujuModelAlreadyExists(
- "Model {} already exists.".format(model_name)
- )
-
# Block until other workers have finished model creation
while self.creating_model.locked():
await asyncio.sleep(0.1)
- # If the model exists, return it from the controller
- if model_name in self.models:
- return
-
# Create the model
async with self.creating_model:
+ if await self.model_exists(model_name, controller=controller):
+ return
self.log.debug("Creating model {}".format(model_name))
model = await controller.add_model(
model_name,
@@ -210,7 +200,6 @@
cloud_name=cloud_name,
credential_name=credential_name or cloud_name,
)
- self.models.add(model_name)
finally:
if model:
await self.disconnect_model(model)
@@ -855,6 +844,9 @@
controller = await self.get_controller()
model = None
try:
+ if not await self.model_exists(model_name, controller=controller):
+ return
+
model = await self.get_model(controller, model_name)
self.log.debug("Destroying model {}".format(model_name))
uuid = model.info.uuid
@@ -866,10 +858,6 @@
# Disconnect model
await self.disconnect_model(model)
- # Destroy model
- if model_name in self.models:
- self.models.remove(model_name)
-
await controller.destroy_model(uuid, force=True, max_wait=0)
# Wait until model is destroyed
diff --git a/n2vc/tests/unit/test_libjuju.py b/n2vc/tests/unit/test_libjuju.py
index b7c7901..9ab6ddb 100644
--- a/n2vc/tests/unit/test_libjuju.py
+++ b/n2vc/tests/unit/test_libjuju.py
@@ -24,7 +24,6 @@
from n2vc.libjuju import Libjuju
from n2vc.exceptions import (
JujuControllerFailedConnecting,
- JujuModelAlreadyExists,
JujuMachineNotFound,
JujuApplicationNotFound,
JujuActionNotFound,
@@ -238,10 +237,10 @@
):
mock_model_exists.return_value = True
- with self.assertRaises(JujuModelAlreadyExists):
- self.loop.run_until_complete(
- self.libjuju.add_model("existing_model", "cloud")
- )
+ # This should not raise an exception
+ self.loop.run_until_complete(
+ self.libjuju.add_model("existing_model", "cloud")
+ )
mock_disconnect_controller.assert_called()