Fabric: Add a CompositeBMC class for parallelizing BMC method calls

This provides a mechanism so we can easily parallelize BMC calls
without having to manually write wrapper functions in the Node and
Fabric classes.

>>> fabric.cbmc.sel_clear()

3 files changed, 72 insertions, 4 deletions

diff --git a/cxmanage_api/fabric.py b/cxmanage_api/fabric.py
index d0d7a10..bd8d6a7 100644
--- a/cxmanage_api/fabric.py
+++ b/cxmanage_api/fabric.py
@@ -56,6 +56,53 @@ class Fabric(object):
     :type node: `Node <node.html>`_
     """
 
+    class CompositeBMC(object):
+        """ Composite BMC object. Provides a mechanism to run BMC
+        commands in parallel across all nodes.
+        """
+
+        def __init__(self, fabric):
+            self.fabric = fabric
+
+        def __getattr__(self, name):
+            """ If the underlying BMCs have a method by this name, then return
+            a callable function that does it in parallel across all nodes.
+            """
+            nodes = self.fabric.nodes
+            task_queue = self.fabric.task_queue
+
+            for node in nodes.values():
+                if ((not hasattr(node.bmc, name)) or
+                    (not hasattr(getattr(node.bmc, name), "__call__"))):
+                    raise AttributeError(
+                        "'CompositeBMC' object has no attribute '%s'"
+                        % name
+                    )
+
+            def function(*args, **kwargs):
+                """ Run the named BMC command in parallel across all nodes. """
+                tasks = {}
+                for node_id, node in nodes.iteritems():
+                    tasks[node_id] = task_queue.put(
+                        getattr(node.bmc, name),
+                        *args,
+                        **kwargs
+                    )
+
+                results = {}
+                errors = {}
+                for node_id, task in tasks.items():
+                    task.join()
+                    if task.status == "Completed":
+                        results[node_id] = task.result
+                    else:
+                        errors[node_id] = task.error
+                if errors:
+                    raise CommandFailedError(results, errors)
+                return results
+
+            return function
+
     def __init__(self, ip_address, username="admin", password="admin",
                   tftp=None, ecme_tftp_port=5001, task_queue=None,
                   verbose=False, node=None):
@@ -68,6 +115,7 @@ class Fabric(object):
         self.task_queue = task_queue
         self.verbose = verbose
         self.node = node
+        self.cbmc = Fabric.CompositeBMC(self)
 
         self._nodes = {}
 
diff --git a/cxmanage_api/tasks.py b/cxmanage_api/tasks.py
index 6b5cfde..7ed7851 100644
--- a/cxmanage_api/tasks.py
+++ b/cxmanage_api/tasks.py
@@ -43,7 +43,7 @@ class Task(object):
     :type args: list
     """
 
-    def __init__(self, method, *args):
+    def __init__(self, method, *args, **kwargs):
         """Default constructor for the Task class."""
         self.status = "Queued"
         self.result = None
@@ -51,6 +51,7 @@ class Task(object):
 
         self._method = method
         self._args = args
+        self._kwargs = kwargs
         self._finished = Event()
 
     def join(self):
@@ -70,7 +71,7 @@ class Task(object):
         """Execute this task. Should only be called by TaskWorker."""
         self.status = "In Progress"
         try:
-            self.result = self._method(*self._args)
+            self.result = self._method(*self._args, **self._kwargs)
             self.status = "Completed"
         except Exception as e:
             self.error = e
@@ -96,7 +97,7 @@ class TaskQueue(object):
         self._queue = deque()
         self._workers = 0
 
-    def put(self, method, *args):
+    def put(self, method, *args, **kwargs):
         """Add a task to the task queue, and spawn a worker if we're not full.
 
         :param method: Named method to run.
@@ -110,7 +111,7 @@ class TaskQueue(object):
         """
         self._lock.acquire()
 
-        task = Task(method, *args)
+        task = Task(method, *args, **kwargs)
         self._queue.append(task)
 
         if self._workers < self.threads:
diff --git a/cxmanage_test/fabric_test.py b/cxmanage_test/fabric_test.py
index 9d6de38..f2720c9 100644
--- a/cxmanage_test/fabric_test.py
+++ b/cxmanage_test/fabric_test.py
@@ -407,6 +407,25 @@ class FabricTest(unittest.TestCase):
             else:
                 self.assertEqual(node.bmc.executed, [])
 
+    def test_composite_bmc(self):
+        """ Test the CompositeBMC member """
+        with self.assertRaises(AttributeError):
+            self.fabric.cbmc.fake_method
+
+        self.fabric.cbmc.set_chassis_power("off")
+        results = self.fabric.cbmc.get_chassis_status()
+
+        self.assertEqual(len(results), len(self.fabric.nodes))
+        for node_id in self.fabric.nodes:
+            self.assertFalse(results[node_id].power_on)
+
+        for node in self.fabric.nodes.values():
+            self.assertEqual(node.bmc.executed, [
+                ("set_chassis_power", "off"),
+                "get_chassis_status"
+            ])
+
+
 class DummyNode(object):
     """ Dummy node for the nodemanager tests """
     def __init__(self, ip_address, username="admin", password="admin",