Add action description

Add action get_description in class BaseAction.
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Partially Implements: blueprint dynamic-action-description

Change-Id: I9ce1b18ad8c5eb7db62ec926d1859d0f508074b0

watcher/applier/actions/base.py

@@ -129,3 +129,8 @@ class BaseAction(loadable.Loadable):
     def validate_parameters(self):
         self.schema(self.input_parameters)
         return True
+
+    @abc.abstractmethod
+    def get_description(self):
+        """Description of the action"""
+        raise NotImplementedError()

watcher/applier/actions/change_nova_service_state.py

@@ -101,3 +101,9 @@ class ChangeNovaServiceState(base.BaseAction):
 
     def post_condition(self):
         pass
+
+    def get_description(self):
+        """Description of the action"""
+        return ("Disables or enables the nova-compute service."
+                "A disabled nova-compute service can not be selected "
+                "by the nova for future deployment of new server.")

watcher/applier/actions/migration.py

@@ -172,3 +172,7 @@ class Migrate(base.BaseAction):
     def post_condition(self):
         # TODO(jed): check extra parameters (network response, etc.)
         pass
+
+    def get_description(self):
+        """Description of the action"""
+        return "Moving a VM instance from source_node to destination_node"

watcher/applier/actions/nop.py

@@ -65,3 +65,7 @@ class Nop(base.BaseAction):
 
     def post_condition(self):
         pass
+
+    def get_description(self):
+        """Description of the action"""
+        return "Logging a NOP message"

watcher/applier/actions/resize.py

@@ -104,3 +104,7 @@ class Resize(base.BaseAction):
     def post_condition(self):
         # TODO(jed): check extra parameters (network response, etc.)
         pass
+
+    def get_description(self):
+        """Description of the action"""
+        return "Resize a server with specified flavor."

watcher/applier/actions/sleep.py

@@ -66,3 +66,7 @@ class Sleep(base.BaseAction):
 
     def post_condition(self):
         pass
+
+    def get_description(self):
+        """Description of the action"""
+        return "Wait for a given interval in seconds."

watcher/tests/applier/workflow_engine/test_default_workflow_engine.py

@@ -52,6 +52,9 @@ class FakeAction(abase.BaseAction):
     def execute(self):
         raise ExpectedException()
 
+    def get_description(self):
+        return "fake action, just for test"
+
 
 class TestDefaultWorkFlowEngine(base.DbTestCase):
     def setUp(self):