Merge pull request #15 from juju/run-action

[osm/N2VC.git] / juju / unit.py

diff --git a/juju/unit.py b/juju/unit.py
index 6a853c2..d0a70bd 100644 (file)
--- a/juju/unit.py
+++ b/juju/unit.py
@@ -1,4 +1,3 @@
-import asyncio
 import logging
 from datetime import datetime
 
@@ -57,6 +56,10 @@ class Unit(model.ModelEntity):
         """
         return self.data['workload-status']['message']
 
+    @property
+    def tag(self):
+        return 'unit-%s' % self.name.replace('/', '-')
+
     def add_storage(self, name, constraints=None):
         """Add unit storage dynamically.
 
@@ -119,34 +122,6 @@ class Unit(model.ModelEntity):
         log.debug(
             'Running `%s` on %s', command, self.name)
 
-        action_status = asyncio.Queue(loop=self.model.loop)
-        tag = None
-
-        async def wait_for_tag():
-            while tag is None:
-                asyncio.sleep(0.1)
-            return tag
-
-        async def callback(delta, old, new, model):
-            # Wait until we have something to report
-            if not new:
-                return
-
-            # Verify that we have the the right action.
-            tag = await wait_for_tag()
-            if not new.id in tag:
-                return
-
-            # Wait until the action has completed, or errored out.
-            if new.status not in ['completed', 'error']:
-                return
-
-            # Put the action in our queue, so that we can fetch it
-            # with the await below.
-            await action_status.put(new)
-
-        self.model.add_observer(callback, 'action', None)
-
         res = await action.Run(
             [],
             command,
@@ -154,22 +129,41 @@ class Unit(model.ModelEntity):
             timeout,
             [self.name],
         )
-        tag = res.results[0].action.tag  # Set the tag for our waiter above.
-        ret = await action_status.get()  # Wait for our callback to fire
-        return (
-            ret.results['Stdout'],
-            ret.results['Stderr'],
-            ret.results['Code']
-        )
+        return await self.model.wait_for_action(res.results[0].action.tag)
 
-    def run_action(self, action_name, **params):
-        """Run action on this unit.
+    async def run_action(self, action_name, **params):
+        """Run an action on this unit.
 
         :param str action_name: Name of action to run
         :param \*\*params: Action parameters
-
-        """
-        pass
+        :returns: An `juju.action.Action` instance.
+
+        Note that this only enqueues the action.  You will need to call
+        ``action.wait()`` on the resulting `Action` instance if you wish
+        to block until the action is complete.
+        """
+        action_facade = client.ActionFacade()
+        action_facade.connect(self.connection)
+
+        log.debug('Starting action `%s` on %s', action_name, self.name)
+
+        res = await action_facade.Enqueue([client.Action(
+            name=action_name,
+            parameters=params,
+            receiver=self.tag,
+        )])
+        action = res.results[0].action
+        error = res.results[0].error
+        if error and error.code == 'not found':
+            raise ValueError('Action `%s` not found on %s' % (action_name,
+                                                              self.name))
+        elif error:
+            raise Exception('Unknown action error: %s' % error.serialize())
+        action_id = action.tag[len('action-'):]
+        log.debug('Action started as %s', action_id)
+        # we can't use wait_for_new here because we don't
+        # consistently (ever?) get an "add" delta for the action
+        return await self.model._wait('action', action_id, None)
 
     def scp(
             self, source_path, user=None, destination_path=None, proxy=False,
@@ -212,3 +206,26 @@ class Unit(model.ModelEntity):
 
         """
         pass
+
+    async def is_leader_from_status(self):
+        """
+        Check to see if this unit is the leader. Returns True if so, and
+        False if it is not, or if leadership does not make sense
+        (e.g., there is no leader in this application.)
+
+        This method is a kluge that calls FullStatus in the
+        ClientFacade to get its information. Once
+        https://bugs.launchpad.net/juju/+bug/1643691 is resolved, we
+        should add a simple .is_leader property, and deprecate this
+        method.
+
+        """
+        app = self.name.split("/")[0]
+
+        c = client.ClientFacade()
+        c.connect(self.model.connection)
+
+        status = await c.FullStatus(None)
+
+        return status.applications[app]['units'][self.name].get(
+            'leader', False)