Periodically log when integrations are taking a while to setup (#36208)

* Periodicly log when intergrations are taking a while to setup

When one or more intergrations are taking a while to setup
it is hard to determine which one is the cause.  We can
help narrow this down for the user with a periodic log
message about which domains are still waiting to be setup
every 30s.

* 30 -> 60 per discussion

* only log when the integration is actually doing setup

* reduce, fix race in test

homeassistant/bootstrap.py

@@ -20,7 +20,7 @@ from homeassistant.const import (
 )
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers.typing import ConfigType
-from homeassistant.setup import DATA_SETUP, async_setup_component
+from homeassistant.setup import DATA_SETUP, DATA_SETUP_STARTED, async_setup_component
 from homeassistant.util.logging import async_activate_log_queue_handler
 from homeassistant.util.package import async_get_user_site, is_virtual_env
 from homeassistant.util.yaml import clear_secret_cache
@@ -32,6 +32,8 @@ ERROR_LOG_FILENAME = "home-assistant.log"
 # hass.data key for logging information.
 DATA_LOGGING = "logging"
 
+LOG_SLOW_STARTUP_INTERVAL = 60
+
 DEBUGGER_INTEGRATIONS = {"ptvsd"}
 CORE_INTEGRATIONS = ("homeassistant", "persistent_notification")
 LOGGING_INTEGRATIONS = {"logger", "system_log", "sentry"}
@@ -323,13 +325,30 @@ async def _async_set_up_integrations(
 ) -> None:
     """Set up all the integrations."""
 
+    setup_started = hass.data[DATA_SETUP_STARTED] = {}
+
     async def async_setup_multi_components(domains: Set[str]) -> None:
         """Set up multiple domains. Log on failure."""
+
+        async def _async_log_pending_setups() -> None:
+            """Periodic log of setups that are pending for longer than LOG_SLOW_STARTUP_INTERVAL."""
+            while True:
+                await asyncio.sleep(LOG_SLOW_STARTUP_INTERVAL)
+                remaining = [domain for domain in domains if domain in setup_started]
+
+                if remaining:
+                    _LOGGER.info(
+                        "Waiting on integrations to complete setup: %s",
+                        ", ".join(remaining),
+                    )
+
         futures = {
             domain: hass.async_create_task(async_setup_component(hass, domain, config))
             for domain in domains
         }
+        log_task = hass.loop.create_task(_async_log_pending_setups())
         await asyncio.wait(futures.values())
+        log_task.cancel()
         errors = [domain for domain in domains if futures[domain].exception()]
         for domain in errors:
             exception = futures[domain].exception()