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

HTTP File Server

The container includes an optional HTTP file server (port 80) for serving game files to clients. This is useful for fast downloads of custom maps and content.

The file server is configured via environment variables:

• HTTP_FILESERVER_ENABLED - Enable/disable the file server
• HTTP_FILESERVER_WEB_ROOT - Root directory for file serving
• HTTP_FILESERVER_FILE_PATTERN - Pattern for files to serve

Additional Resources

• Server Options