do not use root mysql account.

docker-compose.yml

@@ -9,8 +9,8 @@ services:
       BLOG_DB_CONNECTION: mysql
       BLOG_MYSQL_HOST: mariadb
       BLOG_MYSQL_PORT: 3306
-      BLOG_MYSQL_USER: root
-      BLOG_MYSQL_PASS: root
+      BLOG_MYSQL_USER: blog
+      BLOG_MYSQL_PASS: blog # use secure password
       BLOG_DB_NAME: blog
     restart: unless-stopped
     ports:
@@ -21,8 +21,10 @@ services:
     image: mariadb:10.1
     container_name: blog_mariadb
     environment:
+      MYSQL_USER: blog
+      MYSQL_PASSWORD: blog # use secure password
       MYSQL_DATABASE: blog
-      MYSQL_ROOT_PASSWORD: root
+      MYSQL_ROOT_PASSWORD: root # use secure password
     restart: unless-stopped
     volumes:
       - mariadb:/var/lib/mysql