Add Voluptuous to validate the action parameters

We want a simplest way to validate the input parameters of an
Action through a schema.

APIImpact
DocImpact
Partially implements: blueprint watcher-add-actions-via-conf

Change-Id: I139775f467fe7778c7354b0cfacf796fc27ffcb2

watcher/applier/actions/base.py

@@ -27,10 +27,15 @@ from watcher.common import clients
 
 @six.add_metaclass(abc.ABCMeta)
 class BaseAction(object):
+    # NOTE(jed) by convention we decided
+    # that the attribute "resource_id" is the unique id of
+    # the resource to which the Action applies to allow us to use it in the
+    # watcher dashboard and will be nested in input_parameters
+    RESOURCE_ID = 'resource_id'
+
     def __init__(self, osc=None):
         """:param osc: an OpenStackClients instance"""
         self._input_parameters = {}
-        self._applies_to = ""
         self._osc = osc
 
     @property
@@ -48,12 +53,8 @@ class BaseAction(object):
         self._input_parameters = p
 
     @property
-    def applies_to(self):
-        return self._applies_to
-
-    @applies_to.setter
-    def applies_to(self, a):
-        self._applies_to = a
+    def resource_id(self):
+        return self.input_parameters[self.RESOURCE_ID]
 
     @abc.abstractmethod
     def execute(self):
@@ -70,3 +71,11 @@ class BaseAction(object):
     @abc.abstractmethod
     def postcondition(self):
         raise NotImplementedError()
+
+    @abc.abstractproperty
+    def schema(self):
+        raise NotImplementedError()
+
+    def validate_parameters(self):
+        self.schema(self.input_parameters)
+        return True

watcher/applier/actions/change_nova_service_state.py

@@ -16,7 +16,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-
+import six
+import voluptuous
 
 from watcher._i18n import _
 from watcher.applier.actions import base
@@ -27,13 +28,27 @@ from watcher.decision_engine.model import hypervisor_state as hstate
 
 class ChangeNovaServiceState(base.BaseAction):
 
+    STATE = 'state'
+
+    @property
+    def schema(self):
+        return voluptuous.Schema({
+            voluptuous.Required(self.RESOURCE_ID):
+                voluptuous.All(
+                    voluptuous.Any(*six.string_types),
+                    voluptuous.Length(min=1)),
+            voluptuous.Required(self.STATE):
+                voluptuous.Any(*[state.value
+                                 for state in list(hstate.HypervisorState)]),
+        })
+
     @property
     def host(self):
-        return self.applies_to
+        return self.resource_id
 
     @property
     def state(self):
-        return self.input_parameters.get('state')
+        return self.input_parameters.get(self.STATE)
 
     def execute(self):
         target_state = None

watcher/applier/actions/factory.py

@@ -33,5 +33,10 @@ class ActionFactory(object):
         loaded_action = self.action_loader.load(name=object_action.action_type,
                                                 osc=osc)
         loaded_action.input_parameters = object_action.input_parameters
-        loaded_action.applies_to = object_action.applies_to
+        LOG.debug("Checking the input parameters")
+        # NOTE(jed) if we change the schema of an action and we try to reload
+        # an older version of the Action, the validation can fail.
+        # We need to add the versioning of an Action or a migration tool.
+        # We can also create an new Action which extends the previous one.
+        loaded_action.validate_parameters()
         return loaded_action

watcher/applier/actions/migration.py

@@ -18,30 +18,63 @@
 #
 
 from oslo_log import log
+import six
+import voluptuous
 
+from watcher._i18n import _
 from watcher.applier.actions import base
 from watcher.common import exception
 from watcher.common import nova_helper
+from watcher.common import utils
 
 LOG = log.getLogger(__name__)
 
 
 class Migrate(base.BaseAction):
+
+    # input parameters constants
+    MIGRATION_TYPE = 'migration_type'
+    LIVE_MIGRATION = 'live'
+    DST_HYPERVISOR = 'dst_hypervisor'
+    SRC_HYPERVISOR = 'src_hypervisor'
+
+    def check_resource_id(self, value):
+        if (value is not None and
+                len(value) > 0 and not
+                utils.is_uuid_like(value)):
+            raise voluptuous.Invalid(_("The parameter"
+                                       " resource_id is invalid."))
+
+    @property
+    def schema(self):
+        return voluptuous.Schema({
+            voluptuous.Required(self.RESOURCE_ID): self.check_resource_id,
+            voluptuous.Required(self.MIGRATION_TYPE,
+                                default=self.LIVE_MIGRATION):
+                                    voluptuous.Any(*[self.LIVE_MIGRATION]),
+            voluptuous.Required(self.DST_HYPERVISOR):
+                voluptuous.All(voluptuous.Any(*six.string_types),
+                               voluptuous.Length(min=1)),
+            voluptuous.Required(self.SRC_HYPERVISOR):
+                voluptuous.All(voluptuous.Any(*six.string_types),
+                               voluptuous.Length(min=1)),
+        })
+
     @property
     def instance_uuid(self):
-        return self.applies_to
+        return self.resource_id
 
     @property
     def migration_type(self):
-        return self.input_parameters.get('migration_type')
+        return self.input_parameters.get(self.MIGRATION_TYPE)
 
     @property
     def dst_hypervisor(self):
-        return self.input_parameters.get('dst_hypervisor')
+        return self.input_parameters.get(self.DST_HYPERVISOR)
 
     @property
     def src_hypervisor(self):
-        return self.input_parameters.get('src_hypervisor')
+        return self.input_parameters.get(self.SRC_HYPERVISOR)
 
     def migrate(self, destination):
         nova = nova_helper.NovaHelper(osc=self.osc)

watcher/applier/actions/nop.py

@@ -18,6 +18,8 @@
 #
 
 from oslo_log import log
+import six
+import voluptuous
 
 from watcher.applier.actions import base
 
@@ -27,9 +29,18 @@ LOG = log.getLogger(__name__)
 
 class Nop(base.BaseAction):
 
+    MESSAGE = 'message'
+
+    @property
+    def schema(self):
+        return voluptuous.Schema({
+            voluptuous.Required(self.MESSAGE): voluptuous.Any(
+                voluptuous.Any(*six.string_types), None)
+        })
+
     @property
     def message(self):
-        return self.input_parameters.get('message')
+        return self.input_parameters.get(self.MESSAGE)
 
     def execute(self):
         LOG.debug("executing action NOP message:%s ", self.message)

watcher/applier/actions/sleep.py

@@ -18,19 +18,29 @@
 #
 import time
 
+
 from oslo_log import log
+import voluptuous
 
 from watcher.applier.actions import base
 
-
 LOG = log.getLogger(__name__)
 
 
 class Sleep(base.BaseAction):
 
+    DURATION = 'duration'
+
+    @property
+    def schema(self):
+        return voluptuous.Schema({
+            voluptuous.Required(self.DURATION, default=1):
+                voluptuous.All(float, voluptuous.Range(min=0))
+        })
+
     @property
     def duration(self):
-        return int(self.input_parameters.get('duration'))
+        return int(self.input_parameters.get(self.DURATION))
 
     def execute(self):
         LOG.debug("Starting action Sleep duration:%s ", self.duration)