Fix automations listening to HOMEASSISTANT_START (#6936)

* Fire EVENT_HOMEASSISTANT_START automations off right away while starting

* Actually have core state be set to 'starting' during boot

* Fix correct start implementation

* Test and deprecate event automation platform on start

* Fix doc strings

* Remove shutting down exception

* More strict when to mark an instance as finished

* Add automation platform to listen for start/shutdown

* When we stop we should wait till it's all done

* Fix testing

* Fix async bugs in tests

* Only set UVLOOP when hass starts from CLI

* This hangs normal asyncio event loop

* Clean up Z-Wave node entity test

homeassistant/components/automation/homeassistant.py

@@ -0,0 +1,55 @@
+"""
+Offer Home Assistant core automation rules.
+
+For more details about this automation rule, please refer to the documentation
+at https://home-assistant.io/components/automation/#homeassistant-trigger
+"""
+import asyncio
+import logging
+
+import voluptuous as vol
+
+from homeassistant.core import callback, CoreState
+from homeassistant.const import (
+    CONF_PLATFORM, CONF_EVENT, EVENT_HOMEASSISTANT_STOP)
+
+EVENT_START = 'start'
+EVENT_SHUTDOWN = 'shutdown'
+_LOGGER = logging.getLogger(__name__)
+
+TRIGGER_SCHEMA = vol.Schema({
+    vol.Required(CONF_PLATFORM): 'homeassistant',
+    vol.Required(CONF_EVENT): vol.Any(EVENT_START, EVENT_SHUTDOWN),
+})
+
+
+@asyncio.coroutine
+def async_trigger(hass, config, action):
+    """Listen for events based on configuration."""
+    event = config.get(CONF_EVENT)
+
+    if event == EVENT_SHUTDOWN:
+        @callback
+        def hass_shutdown(event):
+            """Called when Home Assistant is shutting down."""
+            hass.async_run_job(action, {
+                'trigger': {
+                    'platform': 'homeassistant',
+                    'event': event,
+                },
+            })
+
+        return hass.bus.async_listen_once(EVENT_HOMEASSISTANT_STOP,
+                                          hass_shutdown)
+
+    # Automation are enabled while hass is starting up, fire right away
+    # Check state because a config reload shouldn't trigger it.
+    elif hass.state == CoreState.starting:
+        hass.async_run_job(action, {
+            'trigger': {
+                'platform': 'homeassistant',
+                'event': event,
+            },
+        })
+
+    return lambda: None