Implement container API

src/dependency_injector/containers.pyi

@@ -41,6 +41,7 @@ class Container:
     dependencies: Dict[str, Provider]
     overridden: Tuple[Provider]
     wiring_config: WiringConfiguration
+    auto_load_config: bool = True
     __self__: Self
     def __init__(self) -> None: ...
     def __deepcopy__(self, memo: Optional[Dict[str, Any]]) -> Provider: ...
@@ -58,6 +59,7 @@ class Container:
     def unwire(self) -> None: ...
     def init_resources(self) -> Optional[Awaitable]: ...
     def shutdown_resources(self) -> Optional[Awaitable]: ...
+    def load_config(self) -> None: ...
     def apply_container_providers_overridings(self) -> None: ...
     def reset_singletons(self) -> SingletonResetContext[C_Base]: ...
     def check_dependencies(self) -> None: ...

src/dependency_injector/containers.pyx

@@ -377,6 +377,12 @@ class DynamicContainer(Container):
         else:
             return _sync_ordered_shutdown(resources)
 
+    def load_config(self):
+        """Load configuration."""
+        config: providers.Configuration
+        for config in self.traverse(types=[providers.Configuration]):
+            config.load()
+
     def apply_container_providers_overridings(self):
         """Apply container providers' overridings."""
         for provider in self.traverse(types=[providers.Container]):
@@ -671,6 +677,12 @@ class DeclarativeContainer(Container):
     :type: WiringConfiguration
     """
 
+    auto_load_config = True
+    """Automatically load configuration when the container is created.
+
+    :type: bool
+    """
+
     cls_providers = dict()
     """Read-only dictionary of current container providers.
 
@@ -720,6 +732,9 @@ class DeclarativeContainer(Container):
         container.override_providers(**overriding_providers)
         container.apply_container_providers_overridings()
 
+        if cls.auto_load_config:
+            container.load_config()
+
         if container.is_auto_wiring_enabled():
             container.wire()
 

tests/unit/containers/instance/test_load_config_py2_py3.py

@@ -0,0 +1,44 @@
+"""Tests for container config loading."""
+
+from dependency_injector import containers, providers
+from pytest import fixture
+
+
+@fixture
+def yaml_config_file(tmp_path):
+    yaml_config_file = str(tmp_path / "config.yml")
+    with open(yaml_config_file, "w") as file:
+        file.write(
+            "section1:\n"
+            "  value1: yaml-loaded\n"
+        )
+    return yaml_config_file
+
+
+def test_auto_load_config(yaml_config_file):
+    class ContainerWithConfig(containers.DeclarativeContainer):
+        config = providers.Configuration(yaml_files=[yaml_config_file])
+
+    container = ContainerWithConfig()
+    assert container.config.section1.value1() == "yaml-loaded"
+
+
+def test_manual_load_config(yaml_config_file):
+    class ContainerWithConfig(containers.DeclarativeContainer):
+        auto_load_config = False
+        config = providers.Configuration(yaml_files=[yaml_config_file])
+
+    container = ContainerWithConfig()
+    assert container.config.section1.value1() is None
+
+    container.load_config()
+    assert container.config.section1.value1() == "yaml-loaded"
+
+
+def test_load_config_does_not_affect_class(yaml_config_file):
+    class ContainerWithConfig(containers.DeclarativeContainer):
+        config = providers.Configuration(yaml_files=[yaml_config_file])
+
+    assert ContainerWithConfig.config.section1.value1() is None
+    _ = ContainerWithConfig()
+    assert ContainerWithConfig.config.section1.value1() is None

tests/unit/containers/instance/test_self_py2_py3.py

@@ -1,4 +1,4 @@
-"""Tests for container self provier."""
+"""Tests for container self provider."""
 
 from dependency_injector import containers, providers, errors
 from pytest import raises