Question about docker installation nextcloud-fpm and cron

🚧 Installation
1

So I have a docker instance of nextcloud and using the nextcloud-fpm image behind a nginx reverse proxy:

version: '2.2'

volumes:
  nextcloud:
  db:

services:
  db:
    image: mariadb
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    restart: always
    volumes:
      - /var/lib/nextcloud/db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=..
      - MYSQL_PASSWORD=..
      - MYSQL_DATABASE=..
      - MYSQL_USER=..

  app:
    image: nextcloud:fpm
    links:
      - db
    volumes:
      - /var/lib/nextcloud/data:/var/www/html
    restart: always

  cron:
    image: nextcloud:fpm
    restart: always
    volumes:
      - /var/lib/nextcloud/data:/var/www/html
    entrypoint: /cron.sh
    depends_on:
      - db

  web:
    image: nginx
    ports:
      - 127.0.0.1:5554:80
    links:
      - app
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
    volumes_from:
      - app
    restart: always

I wanted to enable cron as you can see in the docker-compose.yml. I switched the settings to cron inside of the web settings and now I get the error that something is going wrong. The log of the docker-compose shows:

Apr 26 19:33:00 host docker-compose[28836]: cron_1  | crond: wakeup dt=60
Apr 26 19:33:00 host docker-compose[28836]: cron_1  | crond: file www-data:
Apr 26 19:33:00 host docker-compose[28836]: cron_1  | crond:  line php -f /var/www/html/cron.php

How can I check if cron is working properly? Is the error message showing because the cron isn’t coming from inside the app service?

EDIT: Basically the same question mentioned here

2

I’m not familiar with that method of enabling cron. They have a Dockerfile for building cron support into the image. You can find it here under Adding Features.

https://hub.docker.com/_/nextcloud

3

Thanks for the hints! I followed this