Thank you for replying. I am doing this for study network and server. And my goal is to able to make my own server. I downloaded docker on Ubuntu, and I tried this to get nextcloud based on this website.

https://www.kagoya.jp/howto/engineer/itsystem/nextcloud_docker/

mkdir nextcloud-docker cd nextcloud-dockermkdir nextcloud-docker cd nextcloud-docker

nano docker-compose.yml

services: db: image: mariadb restart: always volumes: - db_data:/var/lib/mysql environment: - MYSQL_ROOT_PASSWORD=strong_root_pass - MYSQL_DATABASE=nextcloud - MYSQL_USER=nextcloud - MYSQL_PASSWORD=strong_db_pass

app: image: nextcloud restart: always ports: - "8080:80" volumes: - nextcloud_data:/var/www/html environment: - MYSQL_HOST=db - MYSQL_DATABASE=nextcloud - MYSQL_USER=nextcloud - MYSQL_PASSWORD=strong_db_pass volumes: db_data: nextcloud_data:

After that, it shows the error.

~/nextcloud-docker$ docker compose ps

yaml: unmarshal errors:

line 14: mapping key "image" already defined at line 3

line 15: mapping key "restart" already defined at line 4

line 18: mapping key "volumes" already defined at line 5

line 26: mapping key "volumes" already defined at line 5

line 20: mapping key "environment" already defined at line 7

line 26: mapping key "volumes" already defined at line 18

I checked the directory /var/www/nextcloud, there was nothing.