add hostname to mariadb container and change volume of mariadb container

docker-compose.yml

@@ -1,6 +1,7 @@
 services:
   mariadb:
     container_name: Nextcloud-DB
+    hostname: mariadb
     image: mariadb:10.11
     security_opt:
       - no-new-privileges:false
@@ -31,9 +32,8 @@ services:
       - 3306
     volumes:
       - /var/lib/docker/volumes/nextcloud/db:/var/lib/mysql:rw
-      - /var/lib/docker/volumes/nextcloud/db:/etc/mysql/conf.d:rw
+      - /var/lib/docker/volumes/nextcloud/db_conf:/etc/mysql/conf.d:rw
     environment:
-      - DB_HOST=Nextcloud-DB
       - MYSQL_ROOT_PASSWORD=sda101176
       - MYSQL_PASSWORD=sda101176
       - MYSQL_DATABASE=nextcloud
@@ -77,7 +77,7 @@ services:
       - MYSQL_PASSWORD=sda101176
       - MYSQL_DATABASE=nextcloud
       - MYSQL_USER=nextcloud
-      - MYSQL_HOST=Nextcloud-DB
+      - MYSQL_HOST=mariadb
     healthcheck:
       test: curl -f http://localhost:80/ || exit 1
     volumes: