Add system-check for EVENT_STORAGES setting

bsmain/__init__.py

@@ -2,6 +2,7 @@ from django.core.checks import Warning, register
 from django.conf import settings
 
 from bugsink.app_settings import get_settings
+from events.storage_registry import get_write_storage
 
 
 @register("bsmain")
@@ -14,3 +15,18 @@ def check_no_nested_settings_in_unnested_form(app_configs, **kwargs):
                 f"'BUGSINK' setting."
             ))
     return errors
+
+
+@register("bsmain")
+def check_event_storage_properly_configured(app_configs, **kwargs):
+    errors = []
+    try:
+        #  rather than doing an explicit check, we just run the `get_write_storage` code and see if it throws an error
+        # get_write_storage() touches the whole storage system, so if it fails, we know something is wrong
+        get_write_storage()
+    except ValueError as e:
+        errors.append(Warning(
+            str(e),
+            id="bsmain.W002",
+            ))
+    return errors