Hosting a Valheim dedicated server with Docker (the setup I use)
My friends and I play Valheim on a dedicated server running on my homelab, so the world is always there, even when the person who “hosted” isn’t online. Here’s the exact setup, using the excellent lloesche/valheim-server image.
What you need
- A Linux box with Docker. Valheim is light: my server uses ~1.4 GB of RAM and ~16 % of one CPU core with four players.
- UDP ports 2456–2457.
- Upload bandwidth: roughly 0.5–1 Mbit/s per player.
docker-compose.yml
services:
valheim:
image: lloesche/valheim-server
container_name: valheim
cap_add:
- sys_nice
ports:
- "2456-2457:2456-2457/udp"
volumes:
- ./config:/config # worlds, backups, admin/ban/permit lists
- ./data:/opt/valheim # server files (re-downloadable)
environment:
- TZ=Europe/Berlin # your own time zone
- SERVER_NAME=My Valheim Server
- WORLD_NAME=Dedicated
- SERVER_PASS=${SERVER_PASS}
- SERVER_PUBLIC=false
# only update when nobody is online
- UPDATE_IF_IDLE=true
# built-in world backups: hourly, keep 3 days
- BACKUPS=true
- BACKUPS_CRON=0 * * * *
- BACKUPS_MAX_AGE=3
stop_grace_period: 2m
restart: unless-stoppedPut the password in a .env file next to it (SERVER_PASS=..., at least 5 characters, and it must not contain the server name). Then:
docker compose up -d
docker logs -f valheimThe first start downloads the server (~1 GB) from Steam. When the log says Game server connected, it’s ready.
Settings worth explaining
SERVER_PUBLIC=false: the server doesn’t appear in the in-game community list. Friends join by address. Less random traffic.UPDATE_IF_IDLE=true: Valheim updates often, and a client/server version mismatch means nobody can join. This updates automatically, but never kicks people mid-session.stop_grace_period: 2m: ondocker compose stopthe server saves the world before exiting. Docker’s default 10 seconds can cut that short.- Backups: zip files land in
./config/backups. The world itself lives in./config/worlds_local.
How friends connect
In Valheim: Start Game → Join Game → Add server, then enter your-address:2456 and the password.
- Same house: use the server’s LAN IP.
- From outside: either forward UDP 2456–2457 on the router, or have everyone join over a VPN like Tailscale. A port forward is the only open port I’d consider for a game, because joining is password- or whitelist-protected. Still, think about it first.
World settings (modifiers)
The in-game “World Modifiers” (combat, death penalty, resources, raids, portals) can be set from the server too:
- SERVER_ARGS=-modifier deathpenalty veryeasy -modifier resources most -modifier raids noneThe server log confirms them on start: Setting world modifier: raids->none.