Merge pull request #661 from cloudtools/locked-no-deps

Locked stacks have no dependencies

stacker/stack.py

@@ -89,6 +89,12 @@ def required_by(self):
 
     @property
     def requires(self):
+        # By definition, a locked stack has no dependencies, because we won't
+        # be performing an update operation on the stack. This means, resolving
+        # outputs from dependencies is unnecessary.
+        if self.locked and not self.force:
+            return []
+
         requires = set(self.definition.requires or [])
 
         # Add any dependencies based on output lookups

stacker/tests/test_stack.py

@@ -47,6 +47,32 @@ def test_stack_requires(self):
             stack.requires,
         )
 
+    def test_stack_requires_when_locked(self):
+        definition = generate_definition(
+            base_name="vpc",
+            stack_id=1,
+            variables={
+                "Var1": "${noop fakeStack3::FakeOutput}",
+                "Var2": (
+                    "some.template.value:${output fakeStack2::FakeOutput}:"
+                    "${output fakeStack::FakeOutput}"
+                ),
+                "Var3": "${output fakeStack::FakeOutput},"
+                        "${output fakeStack2::FakeOutput}",
+            },
+            requires=["fakeStack"],
+        )
+        stack = Stack(definition=definition, context=self.context)
+
+        stack.locked = True
+        self.assertEqual(len(stack.requires), 0)
+
+        # TODO(ejholmes): When the stack is in `--force`, it's not really
+        # locked. Maybe it would be better if `stack.locked` were false when
+        # the stack is in `--force`.
+        stack.force = True
+        self.assertEqual(len(stack.requires), 2)
+
     def test_stack_requires_circular_ref(self):
         definition = generate_definition(
             base_name="vpc",