KF2 Dedicated Server on Ubuntu: SteamCMD, WebAdmin, systemd

This page is based on a Chinese-language Steam guide (translated here) for installing a Killing Floor 2 dedicated server on Ubuntu. The author picks Ubuntu because it is close to SteamOS (both derive from Debian) and because SteamCMD can be installed with apt instead of unpacking binaries by hand. For other approaches see KF2 Dedicated Server via SteamCMD and Docker on a VPS.

Install SteamCMD

Create a dedicated user and install SteamCMD:

sudo useradd -m -s /bin/bash steam
sudo add-apt-repository multiverse -y
sudo dpkg --add-architecture i386
sudo apt update -y
sudo apt-get remove needrestart -y
echo steam steam/license note '' | sudo debconf-set-selections
echo steam steam/question select "I AGREE" | sudo debconf-set-selections
sudo apt install steamcmd -y

On other Linux distributions follow the SteamCMD wiki.

Install the server files

sudo -u steam /usr/games/steamcmd +login anonymous +app_update 232130 +quit

Generate the default config

Run the server once so it writes its default configuration:

sudo -u steam /home/steam/.local/share/Steam/steamapps/common/kf2server/Binaries/Win64/KFGameSteamServer.bin.x86_64 kf-bioticslab

Quick configuration (WebAdmin only)

For people unfamiliar with Linux the simplest route is to enable the web console and change everything else there. The files involved sit under .../kf2server/KFGame/Config/.

1. In KFWeb.ini, section [IpDrv.WebServer], set bEnabled=true. You may change ListenPort from 8080 for safety. A one-liner: sed -i "s/bEnabled=false/bEnabled=true/" .../KFWeb.ini
2. In LinuxServer-KFGame.ini, section [Engine.AccessControl], set AdminPassword= (used for both WebAdmin and in-game admin login). GamePassword= is an optional room password.
3. Disable server takeover in LinuxServer-KFEngine.ini: sed -i "s/bUsedForTakeover=TRUE/bUsedForTakeover=FALSE/" .../LinuxServer-KFEngine.ini

Ports

Cloud servers must allow these ports in the security group or firewall.

Port	Protocol	Purpose
Game Port	UDP	Required. Main game port
Query Port	UDP	Optional. Controls whether the server appears in the public list
Steam Port	UDP	Optional. Steam communication, mainly Workshop downloads
NTP Port	UDP	Optional. Weekly mode only, syncs time with the official servers so weekly missions work
Web Admin	TCP	Optional. WebAdmin, default 8080

Example security group rules (the author uses Alibaba Cloud).

Finally open http://<server-address>:<ListenPort> and log in as Admin with the admin password to configure the remaining parameters.

The WebAdmin console after logging in.

Install community mods

Example: a damage display mod (Workshop ID 2625647922) and a custom max players mod (ID 2143104493). Note the subscription IDs, make sure the server is stopped, and edit LinuxServer-KFEngine.ini:

[IpDrv.TcpNetDriver]
; add this line above all existing DownloadManagers= lines
DownloadManagers=OnlineSubsystemSteamworks.SteamWorkshopDownload

[OnlineSubsystemSteamworks.KFWorkshopSteamworks]
ServerSubscribedWorkshopItems=2625647922
ServerSubscribedWorkshopItems=2143104493

Restart the server and wait for the download. A folder named after each Workshop ID appearing in KFGame\Cache confirms success.

Manage the server

By default the server runs in the foreground and stops when you leave the session. Three options: run it in the background with nohup <command> &, use screen or tmux, or register a systemd service (strongly recommended by the author).

cat <<EOF > /usr/lib/systemd/system/killingfloor2-server.service
[Unit]
Description=killingfloor2-server.service
After=network.target

[Service]
User=steam
Restart=on-failure
RestartSec=30s
ExecStart=/home/steam/.local/share/Steam/steamapps/common/kf2server/Binaries/Win64/KFGameSteamServer.bin.x86_64 kf-bioticslab

[Install]
WantedBy=multi-user.target
EOF

Command	Purpose
systemctl start killingfloor2-server	Start the server
systemctl status killingfloor2-server	Show status
systemctl stop killingfloor2-server	Stop the server
systemctl restart killingfloor2-server	Restart the server

To start it on boot: systemctl enable killingfloor2-server --now.

The service running under systemd.

One-shot install script

The guide ends with a bash script that chains all of the steps above: it creates the steam user if missing, adds the multiverse repository and the i386 architecture, installs SteamCMD, downloads app 232130 into /home/steam/kf2server, runs the server once to generate configs, writes the systemd unit, enables the web console, sets the admin password with sed, disables takeover and finally enables and starts the service. It prints a success message or points to /tmp/killingfloor2_install.log. Change the admin password in the script before using it, and remember to open the ports in your security group.