Nextcloud with Docker: Can't create or write into the data directory

Question

I successfully installed Nextcloud 13.0 using Docker and Docker Compose.

Here's the GitHub repo of the Docker image of Nextcloud: https://github.com/nextcloud/docker

By default, my Nextcloud installation stores data to the following path:

/var/lib/docker/volumes/nextcloud_nextcloud/_data/data/user/files

My /var folder is located on a small partition while /home folder has about 2Tb of storage space. I'm trying to setup Nextcloud to store uploaded files to /home/iamdocker/nextcloud/data on the host machine but it doesn't work.

The Nextcloud configuration page displays the following message :

Error

Can't create or write into the data directory /home/iamdocker/nextcloud/data/

My Nextcloud installation (running in a Docker container) doesn't have the permission to write.

.env

MYSQL_ROOT_PASSWORD=***********************
MYSQL_DATABASE=nextcloud
MYSQL_USER=nextcloud
MYSQL_PASSWORD=************************************
MYSQL_HOST=db

NEXTCLOUD_VERSION=13.0
NEXTCLOUD_ADMIN_USER=example
NEXTCLOUD_ADMIN_PASSWORD=********************************
NEXTCLOUD_TABLE_PREFIX=nc_
NEXTCLOUD_DATA_DIR=/home/iamdocker/nextcloud/data/

docker-compose.yml

version: '2'

volumes:
  nextcloud:
  db:

services:
  db:
    image: mariadb
    env_file:
      - .env
    restart: always
    volumes:
      - db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
      - MYSQL_DATABASE=${MYSQL_DATABASE}
      - MYSQL_USER=${MYSQL_USER}
      - MYSQL_PASSWORD=${MYSQL_PASSWORD}

  app:
    image: nextcloud:${NEXTCLOUD_VERSION}
    env_file:
      - .env
    ports:
      - 8081:80
    links:
      - db
    volumes:
      - nextcloud:/var/www/html
      - ./data:/var/www/html/data
    environment:
      - NEXTCLOUD_ADMIN_USER=${NEXTCLOUD_ADMIN_USER}
      - NEXTCLOUD_ADMIN_PASSWORD=${NEXTCLOUD_ADMIN_PASSWORD}
      - NEXTCLOUD_TABLE_PREFIX=${NEXTCLOUD_TABLE_PREFIX}
      - NEXTCLOUD_DATA_DIR=${NEXTCLOUD_DATA_DIR}
    restart: always

Thank you.

Answer 1

I figured out what the issue was: wrong path in NEXTCLOUD_DATA_DIR.

The environment variable NEXTCLOUD_DATA_DIR takes the path of Nextcloud's data directory in the container, not the path of the mounted volume on the host machine.

Solution: I replaced /home/iamdocker/nextcloud/data/ with /var/www/html/data in the .env file.

.env

MYSQL_ROOT_PASSWORD=***********************
MYSQL_DATABASE=nextcloud
MYSQL_USER=nextcloud
MYSQL_PASSWORD=************************************
MYSQL_HOST=db

NEXTCLOUD_VERSION=13.0
NEXTCLOUD_ADMIN_USER=example
NEXTCLOUD_ADMIN_PASSWORD=********************************
NEXTCLOUD_TABLE_PREFIX=nc_
NEXTCLOUD_DATA_DIR=/var/www/html/data