Add MAAS support

At the moment, Watcher can use a single bare metal provisioning
service: Openstack Ironic.

We're now adding support for Canonical's MAAS service [1], which
is commonly used along with Juju [2] to deploy Openstack.

In order to do so, we're building a metal client abstraction, with
concrete implementations for Ironic and MAAS. We'll pick the MAAS
client if the MAAS url is provided, otherwise defaulting to Ironic.

For now, we aren't updating the baremetal model collector since it
doesn't seem to be used by any of the existing Watcher strategy
implementations.

[1] https://maas.io/docs
[2] https://juju.is/docs

Implements: blueprint maas-support

Change-Id: I6861995598f6c542fa9c006131f10203f358e0a6

watcher/applier/actions/change_node_power_state.py

@@ -17,17 +17,17 @@
 # limitations under the License.
 #
 
-import enum
 import time
 
+from oslo_log import log
+
 from watcher._i18n import _
 from watcher.applier.actions import base
 from watcher.common import exception
+from watcher.common.metal_helper import constants as metal_constants
+from watcher.common.metal_helper import factory as metal_helper_factory
 
-
-class NodeState(enum.Enum):
-    POWERON = 'on'
-    POWEROFF = 'off'
+LOG = log.getLogger(__name__)
 
 
 class ChangeNodePowerState(base.BaseAction):
@@ -43,8 +43,8 @@ class ChangeNodePowerState(base.BaseAction):
          'state': str,
         })
 
-    The `resource_id` references a ironic node id (list of available
-    ironic node is returned by this command: ``ironic node-list``).
+    The `resource_id` references a baremetal node id (list of available
+    ironic nodes is returned by this command: ``ironic node-list``).
     The `state` value should either be `on` or `off`.
     """
 
@@ -65,8 +65,8 @@ class ChangeNodePowerState(base.BaseAction):
                 },
                 'state': {
                     'type': 'string',
-                    'enum': [NodeState.POWERON.value,
-                             NodeState.POWEROFF.value]
+                    'enum': [metal_constants.PowerState.ON.value,
+                             metal_constants.PowerState.OFF.value]
                 }
             },
             'required': ['resource_id', 'state'],
@@ -86,10 +86,10 @@ class ChangeNodePowerState(base.BaseAction):
         return self._node_manage_power(target_state)
 
     def revert(self):
-        if self.state == NodeState.POWERON.value:
-            target_state = NodeState.POWEROFF.value
-        elif self.state == NodeState.POWEROFF.value:
-            target_state = NodeState.POWERON.value
+        if self.state == metal_constants.PowerState.ON.value:
+            target_state = metal_constants.PowerState.OFF.value
+        elif self.state == metal_constants.PowerState.OFF.value:
+            target_state = metal_constants.PowerState.ON.value
         return self._node_manage_power(target_state)
 
     def _node_manage_power(self, state, retry=60):
@@ -97,30 +97,32 @@ class ChangeNodePowerState(base.BaseAction):
             raise exception.IllegalArgumentException(
                 message=_("The target state is not defined"))
 
-        ironic_client = self.osc.ironic()
-        nova_client = self.osc.nova()
-        current_state = ironic_client.node.get(self.node_uuid).power_state
-        # power state: 'power on' or 'power off', if current node state
-        # is the same as state, just return True
-        if state in current_state:
+        metal_helper = metal_helper_factory.get_helper(self.osc)
+        node = metal_helper.get_node(self.node_uuid)
+        current_state = node.get_power_state()
+
+        if state == current_state.value:
             return True
 
-        if state == NodeState.POWEROFF.value:
-            node_info = ironic_client.node.get(self.node_uuid).to_dict()
-            compute_node_id = node_info['extra']['compute_node_id']
-            compute_node = nova_client.hypervisors.get(compute_node_id)
-            compute_node = compute_node.to_dict()
+        if state == metal_constants.PowerState.OFF.value:
+            compute_node = node.get_hypervisor_node().to_dict()
             if (compute_node['running_vms'] == 0):
-                ironic_client.node.set_power_state(
-                    self.node_uuid, state)
+                node.set_power_state(state)
+            else:
+                LOG.warning(
+                    "Compute node %s has %s running vms and will "
+                    "NOT be shut off.",
+                    compute_node["hypervisor_hostname"],
+                    compute_node['running_vms'])
+                return False
         else:
-            ironic_client.node.set_power_state(self.node_uuid, state)
+            node.set_power_state(state)
 
-        ironic_node = ironic_client.node.get(self.node_uuid)
-        while ironic_node.power_state == current_state and retry:
+        node = metal_helper.get_node(self.node_uuid)
+        while node.get_power_state() == current_state and retry:
             time.sleep(10)
             retry -= 1
-            ironic_node = ironic_client.node.get(self.node_uuid)
+            node = metal_helper.get_node(self.node_uuid)
         if retry > 0:
             return True
         else:
@@ -134,4 +136,4 @@ class ChangeNodePowerState(base.BaseAction):
 
     def get_description(self):
         """Description of the action"""
-        return ("Compute node power on/off through ironic.")
+        return ("Compute node power on/off through Ironic or MaaS.")