Dest path variables

Author: amitfin

.devcontainer.json

@@ -1,44 +1,42 @@
 {
-    "name": "patch",
-    "image": "mcr.microsoft.com/devcontainers/python:3.11-bullseye",
-    "postCreateCommand": "scripts/setup",
-    "forwardPorts": [
-        8123
-    ],
-    "portsAttributes": {
-        "8123": {
-            "label": "Home Assistant",
-            "onAutoForward": "notify"
+  "name": "patch",
+  "image": "mcr.microsoft.com/devcontainers/python:3.11-bullseye",
+  "postCreateCommand": "scripts/setup",
+  "forwardPorts": [8123],
+  "portsAttributes": {
+    "8123": {
+      "label": "Home Assistant",
+      "onAutoForward": "notify"
+    }
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "charliermarsh.ruff",
+        "ms-python.python",
+        "github.vscode-pull-request-github",
+        "ryanluker.vscode-coverage-gutters",
+        "ms-python.vscode-pylance",
+        "esbenp.prettier-vscode",
+        "streetsidesoftware.code-spell-checker"
+      ],
+      "settings": {
+        "files.eol": "\n",
+        "editor.tabSize": 4,
+        "python.pythonPath": "/usr/bin/python3",
+        "python.analysis.autoSearchPaths": false,
+        "python.testing.pytestArgs": ["tests"],
+        "python.testing.unittestEnabled": false,
+        "python.testing.pytestEnabled": true,
+        "editor.formatOnPaste": false,
+        "editor.formatOnSave": true,
+        "editor.formatOnType": true,
+        "files.trimTrailingWhitespace": true,
+        "[python]": {
+          "editor.defaultFormatter": "charliermarsh.ruff"
         }
-    },
-    "customizations": {
-        "vscode": {
-            "extensions": [
-                "charliermarsh.ruff",
-                "ms-python.python",
-                "github.vscode-pull-request-github",
-                "ryanluker.vscode-coverage-gutters",
-                "ms-python.vscode-pylance"
-            ],
-            "settings": {
-                "files.eol": "\n",
-                "editor.tabSize": 4,
-                "python.pythonPath": "/usr/bin/python3",
-                "python.analysis.autoSearchPaths": false,
-                "python.testing.pytestArgs": [
-                    "tests"
-                ],
-                "python.testing.unittestEnabled": false,
-                "python.testing.pytestEnabled": true,
-                "editor.formatOnPaste": false,
-                "editor.formatOnSave": true,
-                "editor.formatOnType": true,
-                "files.trimTrailingWhitespace": true,
-                "[python]": {
-                    "editor.defaultFormatter": "charliermarsh.ruff"
-                }
-            }
-        }
-    },
-    "remoteUser": "vscode"
-}
+      }
+    }
+  },
+  "remoteUser": "vscode"
+}

README.md

@@ -26,7 +26,7 @@ patch:
   files:
     - name: adm_mapping.json
       base: /share/fileserver/pysiaalarm/base/data
-      destination: /usr/local/lib/python3.11/site-packages/pysiaalarm/data
+      destination: "{site-packages}/pysiaalarm/data"
       patch: /share/fileserver/pysiaalarm/patch/data
 ```
 
@@ -43,6 +43,11 @@ If a patch was applied (to one file or more) the integration initiates a restart
 
 All files must exist (e.g. `base/name`, etc') inside the Home Assistant Core environment. It’s convenient to mount `base` and `patch` directories as [network shares](https://www.home-assistant.io/common-tasks/os#network-storage).
 
+The directories can use the following variables:
+
+1. `site-packages`: path to the location of Python libraries (e.g. `/usr/local/lib/python3.11/site-packages`).
+2. `homeassistant`: path to the `homeassistant` directory, i.e. `/usr/src/homeassistant/homeassistant` (the 2nd `/homeassistant` is not a mistake. There is `homeassistant` directory under the root.)
+
 ## Install
 
 HACS is the preferred and easier way to install the component, and can be done by using this My button:
@@ -57,8 +62,8 @@ Home Assistant restart is required once the integration files are copied (either
 
 Home Assistant can run in different configurations. A common one is Home Assistant Operating System, which will be used in the explanation below. In this configuration Home Assistant Core runs as a container. The 2 most relevant directories are:
 
-1. `/usr/src/homeassistant`: this is the place with Home Assistant files built from the [Core repository](https://github.com/home-assistant/core).
-2. `/usr/local/lib/python3.11/site-packages`: this is the place where Python libraries are installed. (Note: `python3.11` will be changed when Home Assistant upgrades its Python version.)
+1. `/usr/src/homeassistant`: this is the place with Home Assistant files built from the [Core repository](https://github.com/home-assistant/core). The variable `homeassistant` can be used as a prefix in the `destination` parameter and it will be resolved to `/usr/src/homeassistant/homeassistant` (the 2nd `/homeassistant` is not a mistake. There is `homeassistant` directory under the root.)
+2. `/usr/local/lib/python3.11/site-packages`: this is the place where Python libraries are installed. (Note: `python3.11` will be changed when Home Assistant upgrades its Python version.) The variable `site-packages` can be used as a prefix in the `destination` parameter and it will be resolved automatically.
 
 It’s possible to explore the environment along with the file system structure and content by:
 

custom_components/patch/__init__.py

@@ -4,12 +4,14 @@
 import datetime
 from enum import StrEnum
 import os
+import sys
+
 import voluptuous as vol
 
 import aiofiles
 import aiofiles.os
 
-from homeassistant import config as config_utils
+import homeassistant
 from homeassistant.components.homeassistant import SERVICE_HOMEASSISTANT_RESTART
 from homeassistant.const import (
     CONF_BASE,
@@ -33,12 +35,23 @@
     LOGGER,
 )
 
+PATH_VARIABLES = {
+    "site-packages": next(filter(lambda x: x.endswith("site-packages"), sys.path)),
+    "homeassistant": os.path.dirname(homeassistant.__file__),
+}
+
+
+def expand_path(path: str) -> str:
+    """Expand variables in path string."""
+    return path.format(**PATH_VARIABLES)
+
+
 CONFIG_FILE_SCHEMA = vol.Schema(
     {
         vol.Required(CONF_NAME): cv.string,
-        vol.Required(CONF_BASE): cv.isdir,
-        vol.Required(CONF_DESTINATION): cv.isdir,
-        vol.Required(CONF_PATCH): cv.isdir,
+        vol.Required(CONF_BASE): vol.All(cv.string, expand_path, cv.isdir),
+        vol.Required(CONF_DESTINATION): vol.All(cv.string, expand_path, cv.isdir),
+        vol.Required(CONF_PATCH): vol.All(cv.string, expand_path, cv.isdir),
     },
     extra=vol.ALLOW_EXTRA,
 )
@@ -81,12 +94,12 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
 
     async def async_reload(_: ServiceCall) -> None:
         """Patch the core files using the new configuration."""
-        config = config_utils.load_yaml_config_file(
-            hass.config.path(config_utils.YAML_CONFIG_FILE)
+        config = homeassistant.config.load_yaml_config_file(
+            hass.config.path(homeassistant.config.YAML_CONFIG_FILE)
         )
         if DOMAIN not in config:
             raise IntegrationError(
-                f"'{DOMAIN}' section was not found in {config_utils.YAML_CONFIG_FILE}"
+                f"'{DOMAIN}' section was not found in {homeassistant.config.YAML_CONFIG_FILE}"
             )
         await Patch(hass, CONFIG_SCHEMA({DOMAIN: config[DOMAIN]})[DOMAIN]).run()
 

tests/test_init.py

@@ -30,6 +30,7 @@
     async_fire_time_changed,
 )
 
+from custom_components.patch import expand_path
 from custom_components.patch.const import (
     CONF_DESTINATION,
     CONF_FILES,
@@ -284,3 +285,29 @@ async def test_negative_delay(
         DOMAIN,
         {DOMAIN: {CONF_DELAY: -1}},
     )
+
+
+def test_expand_path() -> None:
+    """Test path with variables."""
+    for variable in ["site-packages", "homeassistant"]:
+        assert expand_path(f"{{{variable}}}").endswith(f"{os.path.sep}{variable}")
+
+
+async def test_expand_path_config(
+    hass: HomeAssistant, freezer: FrozenDateTimeFactory
+) -> None:
+    """Test configuration with variables."""
+    await async_setup(
+        hass,
+        {
+            CONF_FILES: [
+                {
+                    CONF_NAME: "__init__.py",
+                    CONF_BASE: "{site-packages}/aiofiles",
+                    CONF_DESTINATION: "{site-packages}/aiofiles",
+                    CONF_PATCH: "{site-packages}/aiofiles",
+                }
+            ]
+        },
+    )
+    await async_next_day(hass, freezer)