5 files changed, 68 insertions, 15 deletions

diff --git a/tools/cru-py/cru/service/_base.py b/tools/cru-py/cru/service/_base.py
index 7bb09ad..c84ab05 100644
--- a/tools/cru-py/cru/service/_base.py
+++ b/tools/cru-py/cru/service/_base.py
@@ -3,12 +3,19 @@ from __future__ import annotations
 from argparse import ArgumentParser, Namespace
 from abc import ABC, abstractmethod
 from collections.abc import Iterable
+from typing import TypeVar, overload
 
 from cru import CruIterator, CruInternalError
 from cru.app import ApplicationPath, CruApplication
 
+_F = TypeVar("_F")
 
-class AppFeatureProvider(ABC):
+
+class InternalAppException(CruInternalError):
+    pass
+
+
+class AppFeatureProvider:
     def __init__(self, name: str, /, app: AppBase | None = None):
         super().__init__()
         self._name = name
@@ -33,6 +40,8 @@ class AppFeatureProvider(ABC):
         self._app_paths.append(p)
         return p
 
+
+class AppCommandFeatureProvider(AppFeatureProvider, ABC):
     @abstractmethod
     def add_arg_parser(self, arg_parser: ArgumentParser) -> None: ...
 
@@ -71,3 +80,25 @@ class AppBase(CruApplication):
 
     def add_app_feature(self, feature: AppFeatureProvider) -> None:
         self._app_features.append(feature)
+
+    @overload
+    def get_feature(self, feature: str) -> AppFeatureProvider: ...
+
+    @overload
+    def get_feature(self, feature: type[_F]) -> _F: ...
+
+    def get_feature(self, feature: str | type[_F]) -> AppFeatureProvider | _F:
+        if isinstance(feature, str):
+            for f in self._app_features:
+                if f.name == feature:
+                    return f
+        elif isinstance(feature, type):
+            for f in self._app_features:
+                if isinstance(f, feature):
+                    return f
+        else:
+            raise InternalAppException(
+                "Argument must be the name of feature or its class."
+            )
+
+        raise InternalAppException(f"Feature {feature} not found.")
diff --git a/tools/cru-py/cru/service/_config.py b/tools/cru-py/cru/service/_config.py
new file mode 100644
index 0000000..1838015
--- /dev/null
+++ b/tools/cru-py/cru/service/_config.py
@@ -0,0 +1,15 @@
+import os.path
+from ._base import AppFeatureProvider
+from ._data import DataManager
+
+
+class ConfigManager(AppFeatureProvider):
+    def __init__(self, config_file_name="config") -> None:
+        super().__init__("config-manager")
+        self._file_name = config_file_name
+
+    @property
+    def config_file_path(self) -> str:
+        return os.path.join(
+            self.app.get_feature(DataManager).data_dir.full_path, self._file_name
+        )
diff --git a/tools/cru-py/cru/service/_data.py b/tools/cru-py/cru/service/_data.py
new file mode 100644
index 0000000..f38dc23
--- /dev/null
+++ b/tools/cru-py/cru/service/_data.py
@@ -0,0 +1,12 @@
+from cru.app import ApplicationPath
+from ._base import AppFeatureProvider
+
+
+class DataManager(AppFeatureProvider):
+    def __init__(self) -> None:
+        super().__init__("data-manager")
+        self._dir = self.add_app_path("data", True)
+
+    @property
+    def data_dir(self) -> ApplicationPath:
+        return self._dir
diff --git a/tools/cru-py/cru/service/_docker.py b/tools/cru-py/cru/service/_docker.py
index 5958f4f..9b801c4 100644
--- a/tools/cru-py/cru/service/_docker.py
+++ b/tools/cru-py/cru/service/_docker.py
@@ -1,24 +1,19 @@
-import shutil
 import subprocess
 
-from .._util import L
+from cru.tool import ExternalTool
 
 
-class DockerController:
+class DockerController(ExternalTool):
     DOCKER_BIN_NAME = "docker"
 
     def __init__(self, docker_bin: None | str = None) -> None:
-        self._docker_bin = docker_bin
-
-    @property
-    def docker_bin(self) -> str:
-        if self._docker_bin is None:
-            self._docker_bin = shutil.which(self.DOCKER_BIN_NAME)
-        return self._docker_bin
+        super().__init__(docker_bin or self.DOCKER_BIN_NAME)
 
     def list_containers(self) -> L[str]:
-        p = subprocess.run([self.docker_bin, "container", "ls", ""], capture_output=True)
+        p = subprocess.run(
+            [self.docker_bin, "container", "ls", ""], capture_output=True
+        )
         return p.stdout.decode("utf-8").splitlines()
 
     def restart_container(self, container_name: str) -> None:
-        subprocess.run([self.docker_bin, "restart", container_name])
\ No newline at end of file
+        subprocess.run([self.docker_bin, "restart", container_name])
diff --git a/tools/cru-py/cru/service/_template.py b/tools/cru-py/cru/service/_template.py
index 5da00ba..bf13212 100644
--- a/tools/cru-py/cru/service/_template.py
+++ b/tools/cru-py/cru/service/_template.py
@@ -1,12 +1,12 @@
 from argparse import ArgumentParser, Namespace
 
 
-from ._base import AppFeatureProvider
+from ._base import AppCommandFeatureProvider
 from cru.app import ApplicationPath
 from cru.template import TemplateTree
 
 
-class TemplateManager(AppFeatureProvider):
+class TemplateManager(AppCommandFeatureProvider):
     def __init__(self, prefix: str = "CRUPEST"):
         super().__init__("template-manager")
         self._templates_dir = self.add_app_path("templates", True)