Fix update on cert_expiry startup (#27137)

* Don't force extra update on startup

* Skip on entity add instead

* Conditional update based on HA state

* Only force entity state update when postponed

* Clean up state updating

* Delay YAML import

homeassistant/components/cert_expiry/sensor.py

@@ -15,6 +15,7 @@ from homeassistant.const import (
     CONF_PORT,
     EVENT_HOMEASSISTANT_START,
 )
+from homeassistant.core import callback
 from homeassistant.helpers.entity import Entity
 
 from .const import DOMAIN, DEFAULT_NAME, DEFAULT_PORT
@@ -35,18 +36,26 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
 
 async def async_setup_platform(hass, config, async_add_entities, discovery_info=None):
     """Set up certificate expiry sensor."""
-    hass.async_create_task(
-        hass.config_entries.flow.async_init(
-            DOMAIN, context={"source": SOURCE_IMPORT}, data=dict(config)
+
+    @callback
+    def do_import(_):
+        """Process YAML import after HA is fully started."""
+        hass.async_create_task(
+            hass.config_entries.flow.async_init(
+                DOMAIN, context={"source": SOURCE_IMPORT}, data=dict(config)
+            )
         )
-    )
+
+    # Delay to avoid validation during setup in case we're checking our own cert.
+    hass.bus.async_listen_once(EVENT_HOMEASSISTANT_START, do_import)
 
 
 async def async_setup_entry(hass, entry, async_add_entities):
     """Add cert-expiry entry."""
     async_add_entities(
         [SSLCertificate(entry.title, entry.data[CONF_HOST], entry.data[CONF_PORT])],
-        True,
+        False,
+        # Don't update in case we're checking our own cert.
     )
     return True
 
@@ -89,17 +98,22 @@ class SSLCertificate(Entity):
 
     @property
     def available(self):
-        """Icon to use in the frontend, if any."""
+        """Return the availability of the sensor."""
         return self._available
 
     async def async_added_to_hass(self):
         """Once the entity is added we should update to get the initial data loaded."""
 
+        @callback
         def do_update(_):
             """Run the update method when the start event was fired."""
-            self.update()
+            self.async_schedule_update_ha_state(True)
 
-        self.hass.bus.async_listen_once(EVENT_HOMEASSISTANT_START, do_update)
+        if self.hass.is_running:
+            self.async_schedule_update_ha_state(True)
+        else:
+            # Delay until HA is fully started in case we're checking our own cert.
+            self.hass.bus.async_listen_once(EVENT_HOMEASSISTANT_START, do_update)
 
     def update(self):
         """Fetch the certificate information."""