arc/docker.md

Running Arc in Docker

Arc can be run under Docker by running arc.img inside a full hardware-emulated VM (qemux/qemu) that lives inside a Docker container. QEMU (with /dev/kvm acceleration) boots the image exactly like real hardware would, and DSM runs inside that emulated machine. This is a normal, fully working way to run Arc + DSM.

Option 1: Prebuilt image (quickest)

Every release with Docker Hub publishing enabled ships a ready-to-run image with arc.img already baked in — no manual disk setup needed:

docker run -d --name arc \
  --device /dev/kvm --device /dev/net/tun \
  --cap-add NET_ADMIN \
  -p 5000:5000 -p 5001:5001 -p 7080:7080 -p 7304:7304 -p 7681:7681 \
  -v ./data:/storage \
  auxxxilium/arc:latest

Use auxxxilium/arc:<version> instead of :latest to pin a specific release. See the Dockerfile for exactly what this image sets.

Option 2: Build and run your own image

Build arc.img first (see the main README / img-gen.sh), then run it with the following Docker Compose file:

version: "3.9"
services:
  arc:
    image: qemux/qemu:latest
    container_name: arc
    environment:
      BOOT: ""
      RAM_SIZE: "4G"      # >= 4G recommended for DSM
      CPU_CORES: "2"
      DISK_FMT: "qcow2"
      DISK_TYPE: "sata"
      DISK_SIZE: "32G"    # data disk size
      ARGUMENTS: "-device nec-usb-xhci,id=usb0,multifunction=on -drive file=/arc.img,media=disk,format=raw,if=none,id=udisk1 -device usb-storage,bus=usb0.0,port=1,drive=udisk1,bootindex=999,removable=on"
    devices:
      - /dev/kvm
      - /dev/net/tun
    cap_add:
      - NET_ADMIN
    ports:
      - 5000:5000   # DSM management
      - 5001:5001   # DSM management (HTTPS)
      - 7080:7080   # Arc web config (HTTPPORT)
      - 7304:7304   # Arc file browser (DUFSPORT)
      - 7681:7681   # Arc web terminal (TTYDPORT)
    volumes:
      - ./arc.img:/arc.img
      - ./data:/storage
    restart: always
    stop_grace_period: 2m

Notes:

• Replace ./arc.img with the actual path to your built image.
• The port list matches Arc's own defaults (HTTP_PORT/DUFS_PORT/TTYD_PORT in /etc/arc.conf, falling back to 7080/7304/7681) plus DSM's own 5000/5001 once DSM has booted inside the VM. If you changed these via the loader's "Change Loader Ports" menu, update the port mappings to match.
• /dev/kvm is required for hardware-accelerated virtualization; without it QEMU falls back to slow software emulation.
• Once running, configure the loader at http://<host>:7080 the same way you would on real hardware.