How to Set Up a Garry's Mod Dedicated Server

A Garry's Mod dedicated server keeps your gamemode running whether or not you are playing, with its own addons and rules. There are three ways to run one: by hand, in Docker, or managed on Flux.

Option 1: by hand with SteamCMD

The dedicated server is a free, anonymous download from Steam (application 4020), about 7 GB, with native builds for Linux and Windows. It is the Source engine's srcds, configured by its launch line and by cfg/server.cfg.

  1. Install SteamCMD, then run: +login anonymous +force_install_dir ./gmod +app_update 4020 validate +quit
  2. Start it: ./srcds_run -game garrysmod +maxplayers 16 +gamemode sandbox +map gm_construct +host_workshop_collection <id> +rcon_password <password>
  3. Write garrysmod/cfg/server.cfg for everything else: hostname, sv_password, sandbox limits, and exec banned_user.cfg so bans survive a restart.
  4. Open port 27015 for UDP (game and query) and TCP (RCON) in your firewall, and forward it on your router.

Option 2: Docker

runonflux/garrysmod-server-flux, our image (source on GitHub, RunOnFlux/garrysmod-server-flux), installs and updates the server with SteamCMD on every start and builds the launch line from environment variables: GMOD_HOSTNAME, GMOD_GAMEMODE, GMOD_MAP, GMOD_MAXPLAYERS, GMOD_WORKSHOP_COLLECTION, GMOD_RCON_PASSWORD and GAME_PORT.

  • Mount /mnt/gmod/server on a volume: the install is about 7 GB.
  • Mount /mnt/gmod/server/garrysmod on a volume of its own: your server.cfg, addons, gamemodes, data and the logs live there.
  • srcds writes its console only to a terminal: a plain container goes silent once the map is up. The image runs it in one, so the console reaches docker logs, and keeps rotated copies in garrysmod/flux/logs.
  • It always adds +exec banned_user.cfg, or bans written with writeid are gone after a restart.

Option 3: managed on Flux

Deploy a Garry's Mod server on the Flux decentralized cloud, on that same image, with the launch line as a form, the port opened and routed for you, DDoS protection included, and a dashboard with an RCON console, server.cfg as a form, a file browser, a live terminal and backups. Plans start at $4.99 a month.

  1. Pick the 16, 32 or 64-player plan.
  2. Choose a region close to your players.
  3. Name the server, pick the gamemode and map, paste your Workshop collection and deploy. The first start downloads about 7 GB of server files.
  4. Find it by name in Garry's Mod's server browser, or connect with the address from the dashboard.
Deploy a Garry's Mod server →

Frequently asked questions

Is the Garry's Mod dedicated server free?

Yes. It is a free, anonymous download from Steam (application 4020); you do not need to own the game to run it. What costs money is the machine that runs it.

Does the Garry's Mod server run on Linux?

Yes, natively: srcds_run on Linux is what Docker images such as runonflux/garrysmod-server-flux run.

How long does a Garry's Mod server take to start?

The first start downloads about 7 GB; in our tests it was up in three and a half minutes, then downloaded its Workshop collection. After that a restart takes about half a minute.

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