scan-gateway for Nextcloud

A lightweight Docker container that acts as an SMB receiver for network scanners (Brother, OKI, Ricoh, etc.) and automatically uploads scanned documents to a WebDAV destination such as Nextcloud, ownCloud, or any WebDAV-compatible server.

How it works

Scanner (Brother, OKI…) ──► SMB share ──► scan-gateway ──► WebDAV (Nextcloud…)

1. Your scanner sends scanned files to an SMB share exposed by this container
2. The container detects new files and uploads them via WebDAV to your destination
3. Files appear instantly in Nextcloud (or any WebDAV server) without any manual action

Why this exists

Most entry-level and mid-range network scanners (Brother MFC, OKI MB…) support SMB but not WebDAV natively. This container bridges the gap, allowing you to send scans directly to Nextcloud or any WebDAV server without exposing your Nextcloud data folder over SMB.

Requirements

• Docker & Docker Compose
• A network scanner with SMB/CIFS scan-to-folder support
• A WebDAV destination (Nextcloud, ownCloud, Apache, etc.)

Quick start

1. Create the macvlan network

The container needs its own IP on your LAN to avoid port 445 conflicts with the host (e.g. TrueNAS).

docker network create -d macvlan \
  --subnet=192.168.1.0/24 \
  --gateway=192.168.1.1 \
  -o parent=br0 \
  scan-gateway-net

Replace subnet, gateway and parent interface (br0, eth0…) to match your network.
Use ip link show to find your network interface.

2. Build the image

git clone https://github.com/YOUR_USERNAME/scan-gateway-for-nextcloud.git
cd scan-gateway-for-nextcloud
docker build -t scan-gateway:latest .

3. Configure and start

Copy the example compose file and edit it:

cp docker-compose.yml.example docker-compose.yml

Edit docker-compose.yml:

Variable	Description
SMB_USER	Username for the SMB share (used by the scanner)
SMB_PASSWORD	Password for the SMB share
POLL_INTERVAL	How often (seconds) to check for new files (default: 3)
DESTINATIONS	Comma-separated list of destinations (see format below)
ipv4_address	A free IP address on your LAN for the container

DESTINATIONS format

smb_folder|webdav_url|webdav_user|webdav_password

Multiple destinations (one SMB share per destination):

office|https://nextcloud.example.com/remote.php/dav/files/admin/Scans/Office/|admin|app-password,
reception|https://nextcloud.example.com/remote.php/dav/files/admin/Scans/Reception/|admin|app-password2

Tip: Use a Nextcloud app password instead of your main password.

Nextcloud WebDAV URL format

https://YOUR_NEXTCLOUD/remote.php/dav/files/USERNAME/Path/To/Folder/

For Group Folders, the path is:

https://YOUR_NEXTCLOUD/remote.php/dav/files/USERNAME/__groupfolders/FOLDER_NAME/

4. Start

docker compose up -d
docker logs -f scan-gateway

5. Configure your scanner

Field	Value
Server / Host	IP address of the container (e.g. 192.168.1.250)
Share name	The smb_folder name from your DESTINATIONS
Username	Value of SMB_USER
Password	Value of SMB_PASSWORD
Authentication	NTLMv2

TrueNAS SCALE notes

On TrueNAS SCALE, the physical interface is typically bridged (br0). Use br0 as the parent interface for the macvlan network.

If TrueNAS already uses SMB on port 445, the macvlan approach gives the container its own dedicated IP — no port conflict.

Tested with

• Brother MFC-J5345DW
• OKI MB492
• Nextcloud AIO (Docker)
• TrueNAS SCALE 24.10 (Electric Eel)

Contributing

Pull requests welcome! Feel free to open an issue if you have tested with other scanner models or WebDAV servers.

License

MIT