Server Properties

The Lumo server automatically generates server.properties from environment variables. This page explains how the generation works and how to customize it.

How It Works

The entrypoint.sh script generates server.properties on startup using environment variables. This means:

1. No manual editing needed - Configure via ENV vars
2. Updates persist - Changes survive container restarts
3. Defaults provided - Sensible defaults for all properties

Generated Properties

Server Basics

These are generated from environment variables:

Property	ENV Variable	Default
max-players	MAX_PLAYERS	20
motd	MOTD	Welcome to the Lumo Universe!
difficulty	DIFFICULTY	normal
gamemode	GAMEMODE	survival
hardcore	HARDCORE	false
pvp	PVP	true
online-mode	ONLINE_MODE	true

World Configuration

Property	ENV Variable	Default
level-name	-	world
level-type	-	default
level-seed	-	(random)
view-distance	VIEW_DISTANCE	12
simulation-distance	SIMULATION_DISTANCE	10
spawn-protection	SPAWN_PROTECTION	0

Entity Spawning

Property	ENV Variable	Default
spawn-animals	SPAWN_ANIMALS	true
spawn-monsters	SPAWN_MONSTERS	true
spawn-npcs	SPAWN_NPCS	true

Performance

Property	ENV Variable	Default
max-tick-time	MAX_TICK_TIME	-1
network-compression-threshold	NETWORK_COMPRESSION_THRESHOLD	256
entity-broadcast-range-percentage	ENTITY_BROADCAST_RANGE	100

Server Behavior

Property	ENV Variable	Default
allow-flight	ALLOW_FLIGHT	true
enable-command-block	ENABLE_COMMAND_BLOCK	true
white-list	WHITELIST	false
enforce-whitelist	ENFORCE_WHITELIST	false
player-idle-timeout	PLAYER_IDLE_TIMEOUT	0

RCON

Property	ENV Variable	Default
enable-rcon	ENABLE_RCON	true
rcon.password	RCON_PASSWORD	minecraft
rcon.port	RCON_PORT	25575

Manual Customization

If you need properties not covered by environment variables, you can:

Option 1: Edit After First Start

1. Start the container once to generate the file
2. Stop the container
3. Edit the file in the volume
4. Restart

# Start container
docker run -d --name minecraft -e EULA=true -v minecraft_data:/data ghcr.io/lucasilverentand/lumo-server:latest

# Wait for server to start
sleep 60

# Stop server
docker stop minecraft

# Edit server.properties (requires docker cp or volume inspection)
docker run --rm -v minecraft_data:/data -it alpine vi /data/server.properties

# Restart
docker start minecraft

Option 2: Mount Custom File

Create your own server.properties:

server.properties

max-players=50
difficulty=hard
gamemode=survival
motd=My Custom Server
# ... other properties ...

Mount it into the container:

docker run \
  -e EULA=true \
  -v /path/to/server.properties:/data/server.properties:ro \
  ghcr.io/lucasilverentand/lumo-server:latest

Caution

This prevents automatic updates. Environment variables will be ignored for properties in your custom file.

Advanced Properties

Some properties are set automatically and shouldn’t be changed:

Property	Value	Reason
server-port	25565	Docker port mapping handles external port
server-ip	0.0.0.0	Binds to all interfaces (required in container)
enable-query	false	Not needed with RCON
enable-status	true	Required for server list

Port Configuration

The server always uses port 25565 inside the container. Change the external port via Docker:

# External port 25566, internal port 25565
-p 25566:25565

Don’t change server-port in server.properties when using Docker.

JVM Configuration

JVM flags are set in entrypoint.sh using Aikar’s flags:

java -Xms${MEMORY} -Xmx${MEMORY} \
  -XX:+AlwaysPreTouch \
  -XX:+DisableExplicitGC \
  -XX:+ParallelRefProcEnabled \
  -XX:+PerfDisableSharedMem \
  -XX:+UnlockExperimentalVMOptions \
  -XX:+UseG1GC \
  -XX:G1HeapRegionSize=8M \
  -XX:G1HeapWastePercent=5 \
  -XX:G1MaxNewSizePercent=40 \
  -XX:G1MixedGCCountTarget=4 \
  -XX:G1MixedGCLiveThresholdPercent=90 \
  -XX:G1NewSizePercent=30 \
  -XX:G1RSetUpdatingPauseTimePercent=5 \
  -XX:G1ReservePercent=20 \
  -XX:InitiatingHeapOccupancyPercent=15 \
  -XX:MaxGCPauseMillis=200 \
  -XX:MaxTenuringThreshold=1 \
  -XX:SurvivorRatio=32 \
  -Dusing.aikars.flags=https://mcflags.emc.gs \
  -Daikars.new.flags=true \
  -jar paper.jar --nogui

To modify JVM flags, you’ll need to build a custom image with modified entrypoint.sh.

Property Priority

Properties are applied in this order (later overrides earlier):

1. Default values in entrypoint.sh
2. Environment variables
3. Existing server.properties (if already present and not regenerated)

Note

The entrypoint script only generates server.properties if it doesn’t exist or has changed. Manual edits may be overwritten on restart if they conflict with ENV vars.

Examples

Creative Server with Increased View Distance

docker run \
  -e EULA=true \
  -e GAMEMODE=creative \
  -e DIFFICULTY=peaceful \
  -e VIEW_DISTANCE=16 \
  -e ALLOW_FLIGHT=true \
  -e SPAWN_MONSTERS=false \
  ghcr.io/lucasilverentand/lumo-server:latest

Hardcore PvP Server

docker run \
  -e EULA=true \
  -e HARDCORE=true \
  -e DIFFICULTY=hard \
  -e PVP=true \
  -e SPAWN_PROTECTION=0 \
  ghcr.io/lucasilverentand/lumo-server:latest

Whitelisted Private Server

docker run \
  -e EULA=true \
  -e WHITELIST=true \
  -e ENFORCE_WHITELIST=true \
  -e WHITELIST_USERS="Player1,Player2,Player3" \
  -e ONLINE_MODE=true \
  ghcr.io/lucasilverentand/lumo-server:latest

Viewing Current Properties

Check the generated properties:

docker exec minecraft-server cat /data/server.properties

Troubleshooting

Properties Not Updating

If environment variable changes aren’t reflected:

1. Stop the container
2. Remove server.properties from the volume
3. Restart - it will be regenerated

docker stop minecraft-server
docker run --rm -v minecraft_data:/data alpine rm /data/server.properties
docker start minecraft-server

Conflicts with Plugins

Some plugins (like Multiverse) override world settings. Check plugin configs if properties seem ignored.

Next Steps

• Environment Variables - Full ENV reference
• Plugin Configuration - Configure plugins
• Troubleshooting - Common issues