How to Install Docmost on Synology NAS (DS916+) with Docker

This guide explains how to install and run Docmost, an open‑source collaborative wiki and Notion alternative, on a Synology NAS (DS916+ and similar models) using Docker.

The guide focuses on real‑world Synology setups, including Reverse Proxy + WebSocket configuration, which is essential to avoid the common “Real‑time editor connection lost” error.

1. Reverse Proxy Setup (Required for External Access)

To access Docmost via an external domain (for example, docmost.your-domain.i234.me) and to ensure real‑time collaboration works correctly, you must configure Synology’s Reverse Proxy with WebSocket support.

Step 1. Open Reverse Proxy Settings

1. Go to DSM Control Panel
2. Navigate to Login Portal → Advanced
3. Click Reverse Proxy, then click Create

Step 2. General Settings

Configure the basic reverse proxy rule:

• Source
  • Protocol: HTTPS
  • Hostname: docmost.your-domain.i234.me
  • Port: 443
• Destination
  • Protocol: HTTP
  • Hostname: localhost or NAS internal IP (e.g. 192.168.0.4)
  • Port: 3000

This forwards external HTTPS traffic to the Docmost container.

Step 3. (Crucial) Enable WebSocket Headers

This step is mandatory to prevent the real‑time editor connection lost issue.

1. After creating the rule, open it again
2. Go to the Custom Header tab
3. Click Create → WebSocket
4. Synology will automatically add the required headers
5. Click Save

✅ Without this step, collaborative editing will not work reliably.

2. Installation Process

Step 1. Enable SSH

1. Open Control Panel → Terminal & SNMP
2. Enable SSH service

Step 2. Create Installation Directory

1. Open File Station
2. Navigate to the docker shared folder
3. Create a new folder named docmost

Final path:

/volume1/docker/docmost/

Step 3. Create docker-compose.yml

Inside the docmost folder, create a file named docker-compose.yml.

Before using the file, update the following values:

• APP_URL: Your external Docmost domain
• YOUR_DATABASE_PASSWORD: Database password (avoid special characters like @ or $)
• SMTP settings (optional): Use correct mail server credentials

APP_SECRET: A random string of at least 32 characters

openssl rand -hex 32

Final docker-compose.yml

version: '3.8'

services:
  docmost:
    image: docmost/docmost:latest
    container_name: docmost
    restart: unless-stopped
    ports:
      - "3000:3000"
    depends_on:
      - db
      - redis
    environment:
      APP_URL: "https://docmost.your-domain.i234.me"
      APP_SECRET: "ENTER_A_VERY_LONG_RANDOM_SECRET_KEY_HERE"
      DATABASE_URL: "postgresql://docmost:YOUR_DATABASE_PASSWORD@db:5432/docmost?schema=public"
      REDIS_URL: "redis://redis:6379"

      # Optional SMTP configuration (example: Naver Mail)
      EMAIL_FROM: '"Docmost Notification" <your_id@naver.com>'
      SMTP_HOST: "smtp.naver.com"
      SMTP_PORT: "465"
      SMTP_SECURE: "true"
      SMTP_USER: "your_id@naver.com"
      SMTP_PASSWORD: "ENTER_YOUR_NAVER_APP_PASSWORD_HERE"

    volumes:
      - docmost_data:/app/data/storage

  db:
    image: postgres:16-alpine
    container_name: docmost-db
    restart: unless-stopped
    environment:
      POSTGRES_DB: docmost
      POSTGRES_USER: docmost
      POSTGRES_PASSWORD: "SAME_PASSWORD_AS_DATABASE_URL_ABOVE"
    volumes:
      - db_data:/var/lib/postgresql/data

  redis:
    image: redis:7.2-alpine
    container_name: docmost-redis
    restart: unless-stopped
    volumes:
      - redis_data:/data

volumes:
  docmost_data:
  db_data:
  redis_data:

Step 4. Run Docmost via SSH

Connect to your NAS and start the containers:

ssh <DSM_ADMIN_ACCOUNT>@<NAS_INTERNAL_IP>
sudo -i
cd /volume1/docker/docmost/
docker-compose up -d

Docker will download the images and start all services in the background.

3. Useful Docker Commands

Check container status:

docker-compose ps

View logs (useful for troubleshooting):

docker-compose logs -f

Stop and remove containers:

docker-compose down

4. After Installation

• Access Docmost at: https://docmost.your-domain.i234.me
• Create the first admin account
• Verify real‑time editing works (cursor updates, live typing)

For production use, it is recommended to back up Docker volumes regularly using Synology Hyper Backup.

Conclusion

Running Docmost on a Synology NAS with Docker is stable and efficient when Reverse Proxy and WebSocket headers are configured correctly.

This setup provides:

• Secure HTTPS access
• Real‑time collaboration
• Persistent data storage

A solid self‑hosted alternative to Notion for teams and personal knowledge bases.