dev: hold celery worker and beat when pending migrations

apiserver/bin/beat

@@ -2,4 +2,5 @@
 set -e
 
 python manage.py wait_for_db
+python manage.py wait_for_migrations
 celery -A plane beat -l info

apiserver/bin/worker

@@ -2,4 +2,5 @@
 set -e
 
 python manage.py wait_for_db
+python manage.py wait_for_migrations
 celery -A plane worker -l info

apiserver/plane/db/management/commands/wait_for_migrations.py

@@ -0,0 +1,21 @@
+# wait_for_migrations.py
+import time
+from django.core.management.base import BaseCommand
+from django.db.migrations.executor import MigrationExecutor
+from django.db import connections, DEFAULT_DB_ALIAS
+
+class Command(BaseCommand):
+    help = 'Wait for database migrations to complete before starting Celery worker/beat'
+
+    def handle(self, *args, **kwargs):
+        while self._pending_migrations():
+            self.stdout.write("Waiting for database migrations to complete...")
+            time.sleep(10)  # wait for 10 seconds before checking again
+
+        self.stdout.write("All migrations are complete. Safe to start Celery worker/beat.")
+
+    def _pending_migrations(self):
+        connection = connections[DEFAULT_DB_ALIAS]
+        executor = MigrationExecutor(connection)
+        targets = executor.loader.graph.leaf_nodes()
+        return bool(executor.migration_plan(targets))