Implement the meat for DescribeStackEvents

Right now this just adds events for the stack itself via the lifecycle
methods of the FakeStack object, but it is possible to add other kinds
of events (I left a method for that should someone need inspiration
later.)

tests/test_cloudformation/test_cloudformation_stack_crud.py

@@ -354,3 +354,39 @@ def test_update_stack_when_rolled_back():
     ex.error_code.should.equal('ValidationError')
     ex.reason.should.equal('Bad Request')
     ex.status.should.equal(400)
+
+@mock_cloudformation
+def test_describe_stack_events_shows_create_update_and_delete():
+    conn = boto.connect_cloudformation()
+    stack_id = conn.create_stack("test_stack", template_body=dummy_template_json)
+    conn.update_stack(stack_id, template_body=dummy_template_json2)
+    conn.delete_stack(stack_id)
+
+    # assert begins and ends with stack events
+    events = conn.describe_stack_events(stack_id)
+    events[0].resource_type.should.equal("AWS::CloudFormation::Stack")
+    events[-1].resource_type.should.equal("AWS::CloudFormation::Stack")
+
+    # testing ordering of stack events without assuming resource events will not exist
+    stack_events_to_look_for = iter([
+        ("CREATE_IN_PROGRESS", "User Initiated"), ("CREATE_COMPLETE", None),
+        ("UPDATE_IN_PROGRESS", "User Initiated"), ("UPDATE_COMPLETE", None),
+        ("DELETE_IN_PROGRESS", "User Initiated"), ("DELETE_COMPLETE", None)])
+    try:
+        for event in events:
+            event.stack_id.should.equal(stack_id)
+            event.stack_name.should.equal("test_stack")
+
+            if event.resource_type == "AWS::CloudFormation::Stack":
+                event.logical_resource_id.should.equal("test_stack")
+                event.physical_resource_id.should.equal(stack_id)
+
+                status_to_look_for, reason_to_look_for = next(stack_events_to_look_for)
+                event.resource_status.should.equal(status_to_look_for)
+                if reason_to_look_for is not None:
+                    event.resource_status_reason.should.equal(reason_to_look_for)
+    except StopIteration:
+        assert False, "Too many stack events"
+
+    list(stack_events_to_look_for).should.be.empty
+

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -312,3 +312,42 @@ def test_stack_tags():
     expected_tag_items = set(
         item for items in [tag.items() for tag in tags] for item in items)
     observed_tag_items.should.equal(expected_tag_items)
+
+@mock_cloudformation
+def test_stack_events():
+    cf = boto3.resource('cloudformation', region_name='us-east-1')
+    stack = cf.create_stack(
+        StackName="test_stack",
+        TemplateBody=dummy_template_json,
+    )
+    stack.update(TemplateBody=dummy_update_template_json)
+    stack = cf.Stack(stack.stack_id)
+    stack.delete()
+
+    # assert begins and ends with stack events
+    events = list(stack.events.all())
+    events[0].resource_type.should.equal("AWS::CloudFormation::Stack")
+    events[-1].resource_type.should.equal("AWS::CloudFormation::Stack")
+
+    # testing ordering of stack events without assuming resource events will not exist
+    stack_events_to_look_for = iter([
+        ("CREATE_IN_PROGRESS", "User Initiated"), ("CREATE_COMPLETE", None),
+        ("UPDATE_IN_PROGRESS", "User Initiated"), ("UPDATE_COMPLETE", None),
+        ("DELETE_IN_PROGRESS", "User Initiated"), ("DELETE_COMPLETE", None)])
+    try:
+        for event in events:
+            event.stack_id.should.equal(stack.stack_id)
+            event.stack_name.should.equal("test_stack")
+
+            if event.resource_type == "AWS::CloudFormation::Stack":
+                event.logical_resource_id.should.equal("test_stack")
+                event.physical_resource_id.should.equal(stack.stack_id)
+
+                status_to_look_for, reason_to_look_for = next(stack_events_to_look_for)
+                event.resource_status.should.equal(status_to_look_for)
+                if reason_to_look_for is not None:
+                    event.resource_status_reason.should.equal(reason_to_look_for)
+    except StopIteration:
+        assert False, "Too many stack events"
+
+    list(stack_events_to_look_for).should.be.empty