feat: custom image name support for Docker builds (aws#8382)

* feat: custom image name support for Docker builds

* feat: add tests, fix name case

* feat: add some easy tests

---------

Co-authored-by: vicheey <181402101+vicheey@users.noreply.github.com>

Author: dtsulik

samcli/lib/build/app_builder.py

@@ -430,7 +430,8 @@ def _build_lambda_image(self, function_name: str, metadata: Dict, architecture:
         docker_context = cast(str, metadata.get("DockerContext"))
         # Have a default tag if not present.
         tag = metadata.get("DockerTag", "latest")
-        docker_tag = f"{function_name.lower()}:{tag}"
+        image_name = cast(str, metadata.get("DockerImage", function_name))
+        docker_tag = f"{image_name.lower()}:{tag}"
         docker_build_target = metadata.get("DockerBuildTarget", None)
         docker_build_args = metadata.get("DockerBuildArgs", {})
 

tests/unit/lib/build_module/test_app_builder.py

@@ -1749,6 +1749,40 @@ def test_can_build_image_function(self):
 
         self.assertEqual(result, "name:Tag")
 
+    def test_can_build_image_with_custom_name(self):
+        metadata = {
+            "Dockerfile": "Dockerfile",
+            "DockerContext": "context",
+            "DockerImage": "custom-Name_With-symbols-v1.2.3",
+            "DockerTag": "Tag",
+            "DockerBuildArgs": {"a": "b"},
+        }
+
+        self.container_client_mock.images.build.return_value = (Mock(), [])
+
+        result = self.builder._build_lambda_image("Name", metadata, X86_64)
+
+        self.assertEqual(result, "custom-name_with-symbols-v1.2.3:Tag")
+
+    def test_build_lambda_image_raises_for_non_dict_docker_build_args(self):
+        metadata = {
+            "Dockerfile": "Dockerfile",
+            "DockerContext": "context",
+            "DockerTag": "Tag",
+            "DockerBuildArgs": "not-a-dict",
+        }
+        with self.assertRaises(DockerBuildFailed):
+            self.builder._build_lambda_image("Name", metadata, X86_64)
+
+    def test_build_lambda_image_uses_latest_tag_when_not_specified(self):
+        metadata = {
+            "Dockerfile": "Dockerfile",
+            "DockerContext": "context",
+        }
+        self.container_client_mock.images.build.return_value = (Mock(), [])
+        result = self.builder._build_lambda_image("Name", metadata, X86_64)
+        self.assertEqual(result, "name:latest")
+
     @patch("samcli.lib.build.app_builder.SDKBuildClient")
     def test_lazy_initialization_creates_sdk_build_client_by_default(self, mock_sdk_build_client_class):
         """Test that _image_build_client is lazily initialized with SDKBuildClient when use_buildkit is False"""
@@ -3157,6 +3191,14 @@ def setUp(self, mock_get_validated_container_client):
     def tearDown(self):
         EventTracker.clear_trackers()
 
+    def test_must_raise_when_container_manager_is_none(self):
+        self.builder._container_manager = None
+        config = Mock()
+        with self.assertRaises(RuntimeError):
+            self.builder._build_function_on_container(
+                config, "source_dir", "artifacts_dir", "manifest_path", "runtime", X86_64, None
+            )
+
     @patch(
         "samcli.local.docker.container_client_factory.ContainerClientFactory.get_admin_container_preference",
         return_value=None,