Store sessions in database, allowing to load balance web servers.

webapp/config/packages/doctrine.yaml

@@ -17,6 +17,7 @@ doctrine:
             judge_task_type: App\Doctrine\DBAL\Types\JudgeTaskType
         mapping_types:
             enum: string
+        schema_filter: ~^(?!sessions)~
     orm:
         auto_generate_proxy_classes: true
         naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware

webapp/config/packages/framework.yaml

@@ -4,7 +4,7 @@ framework:
     fragments: ~
 
     session:
-        handler_id: ~
+        handler_id: "%env(DATABASE_URL)%"
         cookie_secure: auto
         cookie_samesite: lax
         storage_factory_id: session.storage.factory.native

webapp/migrations/Version20220816125435.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ *
+ * Source: https://symfony.com/doc/current/session/database.html#store-sessions-in-a-relational-database-mariadb-mysql-postgresql
+ */
+final class Version20220816125435 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create a table to store sessions';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql(<<<SQL
+CREATE TABLE `sessions` (
+    `sess_id` VARBINARY(128) NOT NULL PRIMARY KEY,
+    `sess_data` BLOB NOT NULL,
+    `sess_lifetime` INTEGER UNSIGNED NOT NULL,
+    `sess_time` INTEGER UNSIGNED NOT NULL,
+    INDEX `sessions_sess_lifetime_idx` (`sess_lifetime`)
+) COLLATE utf8mb4_bin, ENGINE = InnoDB
+SQL
+        );
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE `sessions`');
+    }
+
+    public function isTransactional(): bool
+    {
+        return false;
+    }
+}