New component: Python Script (#7950)

* Add initial version

* Fix requirements

* Prefer logging over printing

* Set executor thread name on >Py36 only

* Add tests

* Lint

* Add restrictedpython to test dependencies

* Create python_script.py

From doc:
```
However, an empty dict ({}) is treated as is. If you want to specify a list that can contain anything, specify it as dict:
>>> schema = Schema({}, extra=ALLOW_EXTRA)  # don't do this
>>> try:
...   schema({'extra': 1})
...   raise AssertionError('MultipleInvalid not raised')
... except MultipleInvalid as e:
...   exc = e
>>> str(exc) == "not a valid value"
True
>>> schema({})
{}
>>> schema = Schema(dict)  # do this instead
>>> schema({})
{}
>>> schema({'extra': 1})
{'extra': 1}

```

homeassistant/components/python_script.py

@@ -0,0 +1,86 @@
+"""Component to allow running Python scripts."""
+import glob
+import os
+import logging
+
+import voluptuous as vol
+
+DOMAIN = 'python_script'
+REQUIREMENTS = ['restrictedpython==4.0a2']
+FOLDER = 'python_scripts'
+_LOGGER = logging.getLogger(__name__)
+
+CONFIG_SCHEMA = vol.Schema({
+    DOMAIN: vol.Schema(dict)
+}, extra=vol.ALLOW_EXTRA)
+
+
+def setup(hass, config):
+    """Initialize the python_script component."""
+    path = hass.config.path(FOLDER)
+
+    if not os.path.isdir(path):
+        _LOGGER.warning('Folder %s not found in config folder', FOLDER)
+        return False
+
+    def service_handler(call):
+        """Handle python script service calls."""
+        filename = '{}.py'.format(call.service)
+        with open(hass.config.path(FOLDER, filename)) as fil:
+            execute(hass, filename, fil.read(), call.data)
+
+    for fil in glob.iglob(os.path.join(path, '*.py')):
+        name = os.path.splitext(os.path.basename(fil))[0]
+        hass.services.register(DOMAIN, name, service_handler)
+
+    return True
+
+
+def execute(hass, filename, source, data):
+    """Execute a script."""
+    from RestrictedPython import compile_restricted_exec
+    from RestrictedPython.Guards import safe_builtins, full_write_guard
+
+    compiled = compile_restricted_exec(source, filename=filename)
+
+    if compiled.errors:
+        _LOGGER.error('Error loading script %s: %s', filename,
+                      ', '.join(compiled.errors))
+        return
+
+    if compiled.warnings:
+        _LOGGER.warning('Warning loading script %s: %s', filename,
+                        ', '.join(compiled.warnings))
+
+    restricted_globals = {
+        '__builtins__': safe_builtins,
+        '_print_': StubPrinter,
+        '_getattr_': getattr,
+        '_write_': full_write_guard,
+    }
+    local = {
+        'hass': hass,
+        'data': data,
+        'logger': logging.getLogger('{}.{}'.format(__name__, filename))
+    }
+
+    try:
+        _LOGGER.info('Executing %s: %s', filename, data)
+        # pylint: disable=exec-used
+        exec(compiled.code, restricted_globals, local)
+    except Exception as err:  # pylint: disable=broad-except
+        _LOGGER.exception('Error executing script %s: %s', filename, err)
+
+
+class StubPrinter:
+    """Class to handle printing inside scripts."""
+
+    def __init__(self, _getattr_):
+        """Initialize our printer."""
+        pass
+
+    def _call_print(self, *objects, **kwargs):
+        """Print text."""
+        # pylint: disable=no-self-use
+        _LOGGER.warning(
+            "Don't use print() inside scripts. Use logger.info() instead.")

homeassistant/core.py

@@ -113,7 +113,13 @@ class HomeAssistant(object):
         else:
             self.loop = loop or asyncio.get_event_loop()
 
-        self.executor = ThreadPoolExecutor(max_workers=EXECUTOR_POOL_SIZE)
+        executor_opts = {
+            'max_workers': EXECUTOR_POOL_SIZE
+        }
+        if sys.version_info[:2] >= (3, 6):
+            executor_opts['thread_name_prefix'] = 'SyncWorker'
+
+        self.executor = ThreadPoolExecutor(**executor_opts)
         self.loop.set_default_executor(self.executor)
         self.loop.set_exception_handler(async_loop_exception_handler)
         self._pending_tasks = []

requirements_all.txt

@@ -752,6 +752,9 @@ radiotherm==1.2
 # homeassistant.components.raspihats
 # raspihats==2.2.1
 
+# homeassistant.components.python_script
+restrictedpython==4.0a2
+
 # homeassistant.components.rflink
 rflink==0.0.34
 

requirements_test_all.txt

@@ -100,6 +100,9 @@ python-forecastio==1.3.5
 # homeassistant.components.notify.html5
 pywebpush==1.0.4
 
+# homeassistant.components.python_script
+restrictedpython==4.0a2
+
 # homeassistant.components.rflink
 rflink==0.0.34
 

script/gen_requirements_all.py

@@ -65,6 +65,7 @@ TEST_REQUIREMENTS = (
     'gTTS-token',
     'pywebpush',
     'PyJWT',
+    'restrictedpython',
 )
 
 IGNORE_PACKAGES = (

tests/components/test_python_script.py

@@ -0,0 +1,123 @@
+"""Test the python_script component."""
+import asyncio
+import logging
+from unittest.mock import patch, mock_open
+
+from homeassistant.setup import async_setup_component
+from homeassistant.components.python_script import execute
+
+
+@asyncio.coroutine
+def test_setup(hass):
+    """Test we can discover scripts."""
+    scripts = [
+        '/some/config/dir/python_scripts/hello.py',
+        '/some/config/dir/python_scripts/world_beer.py'
+    ]
+    with patch('homeassistant.components.python_script.os.path.isdir',
+               return_value=True), \
+            patch('homeassistant.components.python_script.glob.iglob',
+                  return_value=scripts):
+        res = yield from async_setup_component(hass, 'python_script', {})
+
+    assert res
+    assert hass.services.has_service('python_script', 'hello')
+    assert hass.services.has_service('python_script', 'world_beer')
+
+    with patch('homeassistant.components.python_script.open',
+               mock_open(read_data='fake source'), create=True), \
+            patch('homeassistant.components.python_script.execute') as mock_ex:
+        yield from hass.services.async_call(
+            'python_script', 'hello', {'some': 'data'}, blocking=True)
+
+    assert len(mock_ex.mock_calls) == 1
+    hass, script, source, data = mock_ex.mock_calls[0][1]
+
+    assert hass is hass
+    assert script == 'hello.py'
+    assert source == 'fake source'
+    assert data == {'some': 'data'}
+
+
+@asyncio.coroutine
+def test_setup_fails_on_no_dir(hass, caplog):
+    """Test we fail setup when no dir found."""
+    with patch('homeassistant.components.python_script.os.path.isdir',
+               return_value=False):
+        res = yield from async_setup_component(hass, 'python_script', {})
+
+    assert not res
+    assert 'Folder python_scripts not found in config folder' in caplog.text
+
+
+@asyncio.coroutine
+def test_execute_with_data(hass, caplog):
+    """Test executing a script."""
+    caplog.set_level(logging.WARNING)
+    source = """
+hass.states.set('test.entity', data.get('name', 'not set'))
+    """
+
+    hass.async_add_job(execute, hass, 'test.py', source, {'name': 'paulus'})
+    yield from hass.async_block_till_done()
+
+    assert hass.states.is_state('test.entity', 'paulus')
+
+    # No errors logged = good
+    assert caplog.text == ''
+
+
+@asyncio.coroutine
+def test_execute_warns_print(hass, caplog):
+    """Test print triggers warning."""
+    caplog.set_level(logging.WARNING)
+    source = """
+print("This triggers warning.")
+    """
+
+    hass.async_add_job(execute, hass, 'test.py', source, {})
+    yield from hass.async_block_till_done()
+
+    assert "Don't use print() inside scripts." in caplog.text
+
+
+@asyncio.coroutine
+def test_execute_logging(hass, caplog):
+    """Test logging works."""
+    caplog.set_level(logging.INFO)
+    source = """
+logger.info('Logging from inside script')
+    """
+
+    hass.async_add_job(execute, hass, 'test.py', source, {})
+    yield from hass.async_block_till_done()
+
+    assert "Logging from inside script" in caplog.text
+
+
+@asyncio.coroutine
+def test_execute_compile_error(hass, caplog):
+    """Test compile error logs error."""
+    caplog.set_level(logging.ERROR)
+    source = """
+this is not valid Python
+    """
+
+    hass.async_add_job(execute, hass, 'test.py', source, {})
+    yield from hass.async_block_till_done()
+
+    assert "Error loading script test.py" in caplog.text
+
+
+@asyncio.coroutine
+def test_execute_runtime_error(hass, caplog):
+    """Test compile error logs error."""
+    caplog.set_level(logging.ERROR)
+    source = """
+raise Exception('boom')
+    """
+
+    hass.async_add_job(execute, hass, 'test.py', source, {})
+    yield from hass.async_block_till_done()
+
+    assert "Error executing script test.py" in caplog.text