Docker ARM Synology

Introduction

Synology only offer a docker package on their x64 based NAS. Using this method to install docker on an aarch64 NAS is totally unsupported/untested and totally at your own risk. It is entirely possible it will destroy your NAS.

Summary

The instructions below will:

1. Place the docker binaries in /usr/local/bin/
2. Create a docker config file /usr/local/etc/docker/docker.json
3. Configure docker to save its data to /volume1/docker/var
4. Create a script to start docker on boot at /usr/local/etc/rc.d/docker.sh
5. Create a docker group
6. Place a docker-compose script in /usr/local/bin/

Installation

Log in as root to your synology. Execute the following command:

curl https://gist.githubusercontent.com/ta264/2b7fb6e6466b109b9bf9b0a1d91ebedc/raw/7b11f25c3dce181faa5206aed8051f176cc4e406/get-docker.sh | sh

If all goes well you should see the message:

Done.  Please add your user to the docker group in the Synology GUI and reboot your NAS.

Do as it says:

1. Add your user to the new docker group using the Synology GUI
2. Reboot.

Hopefully you have functioning docker and docker-compose commands, which should work when logged in as your normal user.

Caveats

1. It seems most ARM Synology don't support seccomp, so the docker container has unfettered access to your system (even more so than with a regular docker).
2. Again, due to Synology constraints, all containers need to use --network=host (or network: host in compose) and everything will be directly accessible from the host. There are no port maps.
3. Obviously you can only run aarch64 images, but most hotio and linuxserver images offer an aarch64 version.

Setting up a docker GUI

If you want a GUI you can run Portainer using the following example compose:

version: '2'

services:
  portainer:
    image: portainer/portainer
    restart: unless-stopped
    network_mode: host
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - portainer_data:/data

volumes:
  portainer_data:

Place this in a file called docker-compose.yml in an otherwise empty directory. Run:

docker-compose up -d

Visit http://ip:9000 to complete setup (where ip is the IP address of your synology).

Setting up Sonarr/Radarr/Lidarr/Readarr

For guidance setting up Sonarr/Radarr/Lidarr/Readarr, see the Docker Guide, and remember caveat 2 above.