Build from the LCEMP repository root, not from Minecraft.Server, because the server CMake project depends on sibling Minecraft.Client, Minecraft.World, and cmake directories.

On Windows, use the build wrapper from Minecraft.Server/docker. It uses this order:

Copy an existing Linux binary from build/MinecraftDedicatedServer.
Download a GitHub release asset when GITHUB_REPOSITORY is configured.
Fall back to the full Docker build.

.\build-image.ps1

On Linux/macOS:

./build-image.sh

You can also call Docker directly for a full build:

docker build -f Minecraft.Server/docker/Dockerfile -t lcemp-server .

The Dockerfile defaults to BUILD_JOBS=2 to avoid overloading Docker Desktop/WSL during the large C++ compile. Override it on stronger Linux hosts:

docker build -f Minecraft.Server/docker/Dockerfile -t lcemp-server --build-arg BUILD_JOBS=8 .

To force the wrapper to do a full build:

.\build-image.ps1 -ForceFullBuild

To download a prebuilt binary from a public GitHub release before falling back to the full build:

.\build-image.ps1 `
  -GitHubRepo "owner/repo" `
  -GitHubReleaseTag "latest" `
  -GitHubAssetName "MinecraftDedicatedServer"

The shell wrapper uses equivalent environment variables:

GITHUB_REPOSITORY=owner/repo \
GITHUB_RELEASE_TAG=latest \
GITHUB_ASSET_NAME=MinecraftDedicatedServer \
./build-image.sh

To build a runtime image from an already-built Linux binary directly:

docker build -f Minecraft.Server/docker/Dockerfile.prebuilt -t lcemp-server .

Run with a persistent data directory:

docker run --rm -it \
  -p 25565:25565/tcp \
  -p 25565:25565/udp \
  -p 25566:25566/udp \
  -v lcemp-data:/data \
  -e MOTD="A Minecraft LCE Server" \
  -e LEVEL_NAME="world" \
  lcemp-server

Or use Compose from this directory:

docker compose up --build

To use Compose with an existing build/MinecraftDedicatedServer binary:

docker compose -f compose.yaml -f compose.prebuilt.yaml up --build

The entrypoint writes /data/server.properties from environment variables on every start, then launches MinecraftDedicatedServer from /data so generated worlds, lists, and server data persist in the mounted volume.

Environment Variables

Environment variable	server.properties key	Default
`SERVER_PORT`	`server-port`	`25565`
`SERVER_IP`	`server-ip`	empty
`LEVEL_NAME`	`level-name`	`world`
`LEVEL_SEED`	`level-seed`	empty
`LEVEL_SIZE`	`level-size`	`large`
`GAMEMODE`	`gamemode`	`0`
`DIFFICULTY`	`difficulty`	`2`
`MAX_PLAYERS`	`max-players`	`8`
`PVP`	`pvp`	`true`
`TRUST_PLAYERS`	`trust-players`	`true`
`FIRE_SPREADS`	`fire-spreads`	`true`
`TNT_EXPLODES`	`tnt-explodes`	`true`
`STRUCTURES`	`structures`	`true`
`SPAWN_ANIMALS`	`spawn-animals`	`true`
`SPAWN_NPCS`	`spawn-npcs`	`true`
`ONLINE_MODE`	`online-mode`	`false`
`SHOW_GAMERTAGS`	`show-gamertags`	`true`
`MOTD`	`motd`	`A Minecraft LCE Server`
`WHITE_LIST`	`white-list`	`false`
`VOICE_CHAT`	`voice-chat`	`false`
`ENABLE_CHAT`	`enable-chat`	`false`
`ADVERTISE_LAN`	`advertise-lan`	`true`

SERVER_PROPERTIES_FILE can override the generated properties path. The default is /data/server.properties.

LAN discovery uses UDP broadcast. If clients cannot discover the server through Docker port publishing, run the container with host networking on Linux:

docker run --rm -it --network host -v lcemp-data:/data lcemp-server