Refs kiwitcms#1696. Add middleware to warn for unapplied migrations

tcms/core/middleware.py

@@ -7,6 +7,8 @@
 from django.utils.deprecation import MiddlewareMixin
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
+from django.db import DEFAULT_DB_ALIAS, connections
+from django.db.migrations.loader import MigrationLoader
 
 
 class CsrfDisableMiddleware(MiddlewareMixin):
@@ -32,3 +34,38 @@ def process_request(self, request):
                       }
                 )
             )
+
+
+class CheckUnappliedMigrationsMiddleware(MiddlewareMixin):
+    def process_request(self, request):
+        doc_url = ('https://kiwitcms.readthedocs.io/'
+                   'en/latest/installing_docker.html#initial-configuration-of-running-container')
+        loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
+        graph = loader.graph
+        app_names = sorted(loader.migrated_apps)
+        unapplied_migration_count = 0
+        for app_name in app_names:
+            visited = set()
+            for node in graph.leaf_nodes(app_name):
+                for plan_node in graph.forwards_plan(node):
+                    if plan_node not in visited and plan_node[0] == app_name:
+                        title = plan_node[1]
+                        if graph.nodes[plan_node].replaces:
+                            title += " (%s squashed migrations)" % len(
+                                graph.nodes[plan_node].replaces)
+                        applied_migration = loader.applied_migrations.get(plan_node)
+                        if not applied_migration:
+                            unapplied_migration_count += 1
+                        visited.add(plan_node)
+        if unapplied_migration_count > 0:
+            messages.add_message(
+                request,
+                messages.ERROR,
+                mark_safe(
+                    _('You have %(unapplied_migration_count)s unapplied migration(s). '
+                      'See <a href="%(doc_url)s">documentation</a>') % {
+                          'unapplied_migration_count': unapplied_migration_count,
+                          'doc_url': doc_url,
+                          }
+                )
+            )

tcms/settings/common.py

@@ -130,6 +130,7 @@
     'global_login_required.GlobalLoginRequiredMiddleware',
     'simple_history.middleware.HistoryRequestMiddleware',
     'tcms.core.middleware.CheckSettingsMiddleware',
+    'tcms.core.middleware.CheckUnappliedMigrationsMiddleware'
 ]