Nuclear Option Dedicated Server Docker

A Docker setup for running a Nuclear Option dedicated server.

Prerequisites

• Docker and Docker Compose
• A Steam account that owns Nuclear Option (or use anonymous login if the app supports it)

Quick Start

1. Clone this repository.

2. Create a .env file with your Steam credentials:

   STEAM_USERNAME=your_username
   STEAM_PASSWORD=your_password

   Or use anonymous login:

   STEAM_USERNAME=anonymous

3. Start the server:

   docker compose up -d

The entrypoint will download/update the server files via SteamCMD, apply any overlay files, and launch the server.

Configuration

Server Config via Environment Variables

You can override fields in DedicatedServerConfig.json by setting environment variables prefixed with CONFIG_ in your .env file. The field name is uppercased.

Environment Variable	Type	Description
CONFIG_MISSIONDIRECTORY	string	Path to the missions directory
CONFIG_MODDEDSERVER	boolean	Whether the server is modded (true/false)
CONFIG_HIDDEN	boolean	Hide the server from the browser
CONFIG_SERVERNAME	string	Server name shown in the server browser
CONFIG_PASSWORD	string	Server password (empty for no password)
CONFIG_MAXPLAYERS	number	Maximum number of players
CONFIG_DISABLEERRORKICK	boolean	Disable kicking players on error
CONFIG_NOPLAYERSTOPTIME	number	Seconds before stopping when no players are on
CONFIG_POSTMISSIONDELAY	number	Delay in seconds after a mission ends
CONFIG_ROTATIONTYPE	number	Mission rotation type

Direct Config Editing

You can also edit nuclearoption/DedicatedServerConfig.json directly. This file is mounted into the container at /app.

Overlay

Any files placed in an overlay/ directory will be copied over the server installation at /app on each startup. This is useful for adding custom missions, mods, or overriding specific files.

Volumes

Host Path	Container Path	Purpose
./nuclearoption	/app	Server installation directory
./overlay	/overlay	Optional file overlay

Networking

The container uses network_mode: host, so the server binds directly to the host's network interfaces. No port mapping is needed.

Logs

Server logs are written to nuclearoption/logs/.