How to install docmost on Synology NAS (DS916+) with Docker

This blog provides a comprehensive guide to installing and configuring Docmost, an open-source collaborative wiki and notion alternative, on a Synology NAS (DS916+ and similar models) environment using Docker.

1. Reverse Proxy Setup for External Access

To access Docmost via an external domain (e.g., docmost.your-domain.i234.me) and to fix the "Real-time editor connection lost" error, a reverse proxy setup is essential.

Step 1. Navigate to Reverse Proxy Settings

• Go to DSM Control Panel > Login Portal > Advanced tab.
• Click the Reverse Proxy button and then Create.

Step 2. General Settings

Step 3. (Crucial) Custom Header Settings

• After clicking Create, go to the Custom Header tab.
• Click the Create dropdown menu and select WebSocket.
• This will automatically add the two necessary headers. This step is key to resolving the real-time editing error.
• Click Save to complete the setup.

2. Installation Process

Step 1. Enable SSH

• Go to Control Panel > Terminal & SNMP > Terminal tab, and check 'Enable SSH service'.

Step 2: Create Installation Folder

• Launch File Station in DSM.
• Inside the docker shared folder, create a new folder named docmost.
  • The final path will be /volume1/docker/docmost/.

Step 3: Create docker-compose.yml File

• Inside the docmost folder, create a new file named docker-compose.yml.
• Since you are now using an external domain, you must update the APP_URL value in your docker-compose.yml file.
• <YOUR_NAS_IP_ADDRESS>: Change this to your actual Synology NAS internal IP address (e.g., 192.168.0.4).
• ENTER_A_VERY_LONG_RANDOM_SECRET_KEY_HERE: Replace this with a complex random string of at least 32 characters (e.g., generate one with the `openssl rand -hex 32` command).
• YOUR_DATABASE_PASSWORD: Enter a password for the database. It is recommended to avoid special characters like @ and $.
• SAME_PASSWORD_AS_DATABASE_URL_ABOVE: Enter the same database password you used above.
• (Optional) If using SMTP, enter your correct Naver Mail information and App Password.

# Final docker-compose.yml for Docmost installation (includes SMTP settings)

version: '3.8'
services:
  docmost:
image: docmost/docmost:latest
container_name: docmost
restart: unless-stopped
ports:
  - "3000:3000"
depends_on:
  - db
  - redis
environment:
  # --- Basic Configuration ---
  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 Email Configuration ---
  # Naver Mail Example (delete or comment out these 6 lines if not in use)
  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 5: Execute via SSH

• Open a terminal (PowerShell, PuTTY, etc.) on your PC and connect to your NAS via SSH.
• This command will download all necessary images and create/run the containers in the background.

$ ssh <YOUR_DSM_ADMIN_ACCOUNT>@<YOUR_NAS_IP_ADDRESS>
$ sudo -i                      # Gain root access.
$ cd /volume1/docker/docmost/
$ docker-compose up -d

3. Useful Commands

• Check container status:

$ docker-compose ps

• View real-time logs (useful for diagnosing issues):

$ docker-compose logs -f

• Stop and completely remove containers:

$ docker-compose down