Battlefield 1942 Docker Container

This Docker container provides a Battlefield 1942 game server that automatically downloads the required server files and supports file overlaying using OverlayFS.

Quick Start

services:
  bf1942:
    image: lancommander/bf1942:latest
    container_name: bf1942

    ports:
      - 14567:14567/udp
      - 4711:4711/tcp   # RCON
      - 22000:22000/udp # Queries / heartbeats (LAN)
      - 27900:27900/tcp # Master server heartbeat

    volumes:
      - "/data/Servers/Battlefield 1942:/config"

    environment:
      # START_ARGS: "+statusMonitor 1"

    cap_add:
      - SYS_ADMIN

    security_opt:
      - apparmor:unconfined

    restart: unless-stopped

Configuration Options

Ports

The container exposes the following ports:

• 14567/udp - Main game server port (default). Clients connect to this port to join the server.
• 4711/tcp - RCON port (optional)
• 22000/udp - Queries / heartbeats (LAN) (optional)
• 27900/tcp - Master server heartbeat

Volumes

The container requires a volume mount for the /config directory, which stores:

• Server/ - Base server files
• Overlay/ - Custom files that overlay on top of the game directory
• Merged/ - OverlayFS merged view (auto-created)
• Scripts/ - Custom PowerShell scripts for hooks

Example:

volumes:
  - "/data/Servers/Battlefield 1942:/config"

The host path can be:

• An absolute path (Windows: C:\data\..., Linux: /data/...)
• A relative path (e.g., ./config:/config)
• A named volume (e.g., bf1942-server:/config)

Important: The mounted directory must be writable by the container.

Environment Variables

Variable	Description	Default	Required
START_ARGS	Arguments used to start the game server	"+statusMonitor 1"	No

Security Options

The container requires elevated privileges to use OverlayFS for file overlaying.

cap_add: SYS_ADMIN

Adds the SYS_ADMIN capability, which is required for mounting OverlayFS. This is the recommended approach as it provides minimal necessary privileges.

cap_add:
  - SYS_ADMIN

security_opt: apparmor:unconfined

On Ubuntu hosts with AppArmor enabled, you may need to disable AppArmor restrictions for the container. This is often necessary for OverlayFS to function properly.

security_opt:
  - apparmor:unconfined

Alternative Options:

If you prefer less security but simpler configuration, you can use privileged mode:

privileged: true

Note: Privileged mode grants the container extensive access to the host system and is less secure than using cap_add: SYS_ADMIN.

Restart Policy

restart: unless-stopped

This ensures the container automatically restarts if it stops unexpectedly, but won't restart if you manually stop it.

Other options:

• no - Never restart
• always - Always restart, even after manual stop
• on-failure - Restart only on failure

Directory Structure

The /config directory contains the following structure:

/config/
├── Server/              # Game files from SteamCMD (auto-created)
│   └── mods
|       └── bf1942       # The base game server files
|       └── xpack1       # Road to Rome data files
|       └── xpack2       # Secret Weapons of WWII data files
├── Overlay/             # Custom files overlay (your modifications)
│   └── mods/
│       └── bf1942/
│           └── Levels/  # Custom maps
├── Merged/              # OverlayFS merged view (auto-created)
├── .overlay-work/       # OverlayFS work directory (auto-created)
└── Scripts/
    └── Hooks/           # Custom PowerShell scripts for hooks

OverlayFS

The container uses Linux OverlayFS to merge the base game files with your custom files:

• Lower layer: /config/Server (base game files)
• Upper layer: /config/Overlay (your custom files)
• Merged view: /config/Merged (where the game server runs from)

Benefits:

• Replace files without modifying the base installation
• Add custom content (maps, plugins, configs)
• No file copying required - OverlayFS is a union filesystem
• Easy updates - base game files can be updated without losing customizations

If OverlayFS cannot be mounted (e.g., missing privileges), the container will fall back to using /config/Server directly and log a warning.

Troubleshooting

Container Won't Start

1. Check logs:

   docker logs bf1942

2. Verify permissions: Ensure the mounted volume is writable:

   # Linux
   chmod -R 755 "/data/Servers/Battlefield 1942"
   
   # Windows
   # Ensure the directory has proper permissions in Windows

3. Check security options: Ensure cap_add: SYS_ADMIN is set, or use privileged: true

Game Server Not Starting

1. Verify START_ARGS: Check that START_ARGS contains a valid server arguments:

   START_ARGS: "+statusMonitor 1"

2. Check server directory: Verify that game files were downloaded:

   docker exec bf1942 ls -la /config/Server

3. Review server logs: Check container logs for server startup messages and errors

OverlayFS Warnings

If you see warnings about OverlayFS:

1. Verify capabilities: Ensure cap_add: SYS_ADMIN is present in your docker-compose.yml

2. Check AppArmor: On Ubuntu, add security_opt: apparmor:unconfined

3. Alternative: Use privileged: true (less secure but simpler)

Port Already in Use

If you get port binding errors:

1. Check for existing containers:

   docker ps -a

2. Use different ports: Change the port mapping in docker-compose.yml:

   ports:
     - 27601:27600/udp  # Use a different host port

3. Stop conflicting containers:

   docker stop <container-name>

Advanced Usage

Custom Hooks

You can create custom PowerShell scripts that execute at various points in the container's lifecycle. Place scripts in:

/config/Scripts/Hooks/{HookName}/

Available hooks:

• Prebf1942Install - Before iobf1942 is downloaded/extracted
• Postbf1942Install - After iobf1942 is installed
• PreInstallPatches - Before patch installation
• PostInstallPatches - After patch installation

Example hook script (/config/Scripts/Hooks/Postbf1942Install/10-CustomSetup.ps1):

Write-Host "Running custom setup..."
# Your custom commands here

Additional Resources

• Server Options