Restrict launches to prepared runtime images

agent/tests/test_agent.py

@@ -727,6 +727,29 @@ class AgentTests(unittest.TestCase):
         self.assertEqual(second["result"], first["result"])
         self.assertEqual(sum(call[:2] == ("container", "restart") for call in self.docker.calls), 1)
 
+    def test_creation_uses_cached_runtime_without_allowing_docker_to_pull(self):
+        payload = self.create()
+        creation = next(args for args in self.docker.calls if args[:2] == ("container", "create"))
+        self.assertIn("--pull=never", creation)
+        self.assertEqual(creation[-1], payload["image"])
+        self.assertFalse(any(args[:2] == ("image", "pull") for args in self.docker.calls))
+
+    def test_image_disappearing_after_validation_cannot_be_pulled_or_started(self):
+        original = self.docker.call
+
+        def missing_image(*args, **kwargs):
+            if args[:2] == ("container", "create"):
+                self.assertIn("--pull=never", args)
+                raise AgentError("No such image")
+            return original(*args, **kwargs)
+
+        payload = {"game": "t5", "libraryId": self.library_id, "image": "prepared:runtime", "port": 28960}
+        with patch.object(self.docker, "call", side_effect=missing_image):
+            with self.assertRaisesRegex(AgentError, "No such image"):
+                self.agent.create(INSTANCE, 1, payload)
+        self.assertEqual(self.docker.started, 0)
+        self.assertFalse(any(args[:2] == ("image", "pull") for args in self.docker.calls))
+
     def test_manifest_is_advertised_and_reconciles_as_a_read_operation(self):
         self.create()
         operation = self.operation("files.manifest", {"roots": ["configs", "scripts"], "ignoreNames": [], "paths": ["configs/server.cfg"]})