Just managed to get nextcloud running after like 5 hours of messing around. Because my VPS only has 40GB I had to buy a new volume, point all of docker to the new volume.

All the weird discussions/tutorials online doesn’t really work for me:

In the end I used the official compose.yml file (permalink) and adapted a bit, then it just works. I guess most of the info are outdated.

services:
  nextcloud-aio-mastercontainer:
    image: nextcloud/all-in-one:latest
    init: true
    restart: always
    container_name: nextcloud-aio-mastercontainer # This line is not allowed to be changed as otherwise AIO will not work correctly
    volumes:
      - nextcloud_aio_mastercontainer:/mnt/docker-aio-config # This line is not allowed to be changed as otherwise the built-in backup solution will not work
      - /var/run/docker.sock:/var/run/docker.sock:ro # May be changed on macOS, Windows or docker rootless. See the applicable documentation. If adjusting, don't forget to also set 'WATCHTOWER_DOCKER_SOCKET_PATH'!
    network_mode: bridge # add to the same network as docker run would do
    ports:
      # - 80:80 # Can be removed when running behind a web server or reverse proxy (like Apache, Nginx, Caddy, Cloudflare Tunnel and else). See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      - 8080:8080
      # - 8443:8443 # Can be removed when running behind a web server or reverse proxy (like Apache, Nginx, Caddy, Cloudflare Tunnel and else). See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
    # environment: # Is needed when using any of the options below
      # AIO_DISABLE_BACKUP_SECTION: false # Setting this to true allows to hide the backup section in the AIO interface. See https://github.com/nextcloud/all-in-one#how-to-disable-the-backup-section
      # AIO_COMMUNITY_CONTAINERS: # With this variable, you can add community containers very easily. See https://github.com/nextcloud/all-in-one/tree/main/community-containers#community-containers
      APACHE_PORT: 11000 # Is needed when running behind a web server or reverse proxy (like Apache, Nginx, Caddy, Cloudflare Tunnel and else). See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      APACHE_IP_BINDING: 127.0.0.1 # Should be set when running behind a web server or reverse proxy (like Apache, Nginx, Caddy, Cloudflare Tunnel and else) that is running on the same host. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      APACHE_ADDITIONAL_NETWORK: frontend_net # (Optional) Connect the apache container to an additional docker network. Needed when behind a web server or reverse proxy (like Apache, Nginx, Caddy, Cloudflare Tunnel and else) running in a different docker network on same server. See https://github.com/nextcloud/all-in-one/blob/main/reverse-proxy.md
      # BORG_RETENTION_POLICY: --keep-within=7d --keep-weekly=4 --keep-monthly=6 # Allows to adjust borgs retention policy. See https://github.com/nextcloud/all-in-one#how-to-adjust-borgs-retention-policy
      # COLLABORA_SECCOMP_DISABLED: false # Setting this to true allows to disable Collabora's Seccomp feature. See https://github.com/nextcloud/all-in-one#how-to-disable-collaboras-seccomp-feature
      NEXTCLOUD_DATADIR: /mnt/ncdata # Allows to set the host directory for Nextcloud's datadir. ⚠️⚠️⚠️ Warning: do not set or adjust this value after the initial Nextcloud installation is done! See https://github.com/nextcloud/all-in-one#how-to-change-the-default-location-of-nextclouds-datadir
      NEXTCLOUD_MOUNT: /mnt/ # Allows the Nextcloud container to access the chosen directory on the host. See https://github.com/nextcloud/all-in-one#how-to-allow-the-nextcloud-container-to-access-directories-on-the-host
      NEXTCLOUD_UPLOAD_LIMIT: 16G # Can be adjusted if you need more. See https://github.com/nextcloud/all-in-one#how-to-adjust-the-upload-limit-for-nextcloud
      NEXTCLOUD_MAX_TIME: 3600 # Can be adjusted if you need more. See https://github.com/nextcloud/all-in-one#how-to-adjust-the-max-execution-time-for-nextcloud
      NEXTCLOUD_MEMORY_LIMIT: 512M # Can be adjusted if you need more. See https://github.com/nextcloud/all-in-one#how-to-adjust-the-php-memory-limit-for-nextcloud
      # NEXTCLOUD_TRUSTED_CACERTS_DIR: /path/to/my/cacerts # CA certificates in this directory will be trusted by the OS of the nextcloud container (Useful e.g. for LDAPS) See https://github.com/nextcloud/all-in-one#how-to-trust-user-defined-certification-authorities-ca
      # NEXTCLOUD_STARTUP_APPS: deck twofactor_totp tasks calendar contacts notes # Allows to modify the Nextcloud apps that are installed on starting AIO the first time. See https://github.com/nextcloud/all-in-one#how-to-change-the-nextcloud-apps-that-are-installed-on-the-first-startup
      # NEXTCLOUD_ADDITIONAL_APKS: imagemagick # This allows to add additional packages to the Nextcloud container permanently. Default is imagemagick but can be overwritten by modifying this value. See https://github.com/nextcloud/all-in-one#how-to-add-os-packages-permanently-to-the-nextcloud-container
      # NEXTCLOUD_ADDITIONAL_PHP_EXTENSIONS: imagick # This allows to add additional php extensions to the Nextcloud container permanently. Default is imagick but can be overwritten by modifying this value. See https://github.com/nextcloud/all-in-one#how-to-add-php-extensions-permanently-to-the-nextcloud-container
      # NEXTCLOUD_ENABLE_DRI_DEVICE: true # This allows to enable the /dev/dri device in the Nextcloud container. ⚠️⚠️⚠️ Warning: this only works if the '/dev/dri' device is present on the host! If it should not exist on your host, don't set this to true as otherwise the Nextcloud container will fail to start! See https://github.com/nextcloud/all-in-one#how-to-enable-hardware-acceleration-for-nextcloud
      # ENABLE_NVIDIA_GPU: true # This allows to enable the NVIDIA runtime and GPU access for containers that profit from it. ⚠️⚠️⚠️ Warning: this only works if an NVIDIA gpu is installed on the server. See https://github.com/nextcloud/all-in-one#how-to-enable-hardware-acceleration-for-nextcloud.
      # NEXTCLOUD_KEEP_DISABLED_APPS: false # Setting this to true will keep Nextcloud apps that are disabled in the AIO interface and not uninstall them if they should be installed. See https://github.com/nextcloud/all-in-one#how-to-keep-disabled-apps
      # SKIP_DOMAIN_VALIDATION: false # This should only be set to true if things are correctly configured. See https://github.com/nextcloud/all-in-one?tab=readme-ov-file#how-to-skip-the-domain-validation
      # TALK_PORT: 3478 # This allows to adjust the port that the talk container is using. See https://github.com/nextcloud/all-in-one#how-to-adjust-the-talk-port
      # WATCHTOWER_DOCKER_SOCKET_PATH: /var/run/docker.sock # Needs to be specified if the docker socket on the host is not located in the default '/var/run/docker.sock'. Otherwise mastercontainer updates will fail. For macos it needs to be '/var/run/docker.sock'
    # security_opt: ["label:disable"] # Is needed when using SELinux

#   # Optional: Caddy reverse proxy. See https://github.com/nextcloud/all-in-one/discussions/575
#   # Hint: You need to uncomment APACHE_PORT: 11000 above, adjust cloud.example.com to your domain and uncomment the necessary docker volumes at the bottom of this file in order to make it work
#   # You can find further examples here: https://github.com/nextcloud/all-in-one/discussions/588
   caddy:
     image: caddy:alpine
     restart: always
     container_name: caddy
     volumes:
       - caddy_certs:/certs
       - caddy_config:/config
       - caddy_data:/data
       - caddy_sites:/srv
     network_mode: "host"
     configs:
       - source: Caddyfile
         target: /etc/caddy/Caddyfile
 configs:
   Caddyfile:
     content: |
       # Adjust cloud.example.com to your domain below
       https://cloud.example.com:443 {
         reverse_proxy localhost:11000
       }       

volumes: # If you want to store the data on a different drive, see https://github.com/nextcloud/all-in-one#how-to-store-the-filesinstallation-on-a-separate-drive
  nextcloud_aio_mastercontainer:
    name: nextcloud_aio_mastercontainer # This line is not allowed to be changed as otherwise the built-in backup solution will not work
  caddy_certs:
  caddy_config:
  caddy_data:
  caddy_sites: