chown knockd to minecraft user

.github/workflows/build-multiarch.yml

@@ -18,9 +18,9 @@ jobs:
       matrix:
         # NOTE: the "latest" variant is identified in the Docker meta step's 'latest' config
         variant:
+          - java21-graalvm
           - java20
           - java20-alpine
-          - java20-graalvm
           - java17
           - java17-graalvm
           - java17-jdk
@@ -35,6 +35,11 @@ jobs:
           - java11-openj9
           - java11-jdk
         include:
+        # JAVA 21:
+          - variant: java21-graalvm
+            baseImage: container-registry.oracle.com/graalvm/jdk:21-ol8
+            platforms: linux/amd64,linux/arm64
+            mcVersion: 1.20.2
         # JAVA 20:
           - variant: java20
             baseImage: eclipse-temurin:20-jre
@@ -44,10 +49,6 @@ jobs:
             baseImage: eclipse-temurin:20-jre-alpine
             platforms: linux/amd64
             mcVersion: 1.19.3
-          - variant: java20-graalvm
-            baseImage: container-registry.oracle.com/graalvm/jdk:20-ol8
-            platforms: linux/amd64,linux/arm64
-            mcVersion: 1.19.3
         # JAVA 17:
           - variant: java17
             # jammy doesn't work until minecraft updates to https://github.com/netty/netty/issues/12343

Dockerfile

@@ -9,14 +9,11 @@ ARG TARGETOS
 ARG TARGETARCH
 ARG TARGETVARIANT
 
-# CI system should set this to a hash or git revision of the build directory and it's contents to
-# ensure consistent cache updates.
-ARG BUILD_FILES_REV=1
 RUN --mount=target=/build,source=build \
-    REV=${BUILD_FILES_REV} TARGET=${TARGETARCH}${TARGETVARIANT} /build/run.sh install-packages
+    /build/run.sh setup-user
 
 RUN --mount=target=/build,source=build \
-    REV=${BUILD_FILES_REV} /build/run.sh setup-user
+    TARGET=${TARGETARCH}${TARGETVARIANT} /build/run.sh install-packages
 
 COPY --chmod=644 files/sudoers* /etc/sudoers.d
 
@@ -35,14 +32,14 @@ RUN easy-add --var os=${TARGETOS} --var arch=${TARGETARCH}${TARGETVARIANT} \
   --from https://github.com/itzg/{{.app}}/releases/download/{{.version}}/{{.app}}_{{.version}}_{{.os}}_{{.arch}}.tar.gz
 
 RUN easy-add --var os=${TARGETOS} --var arch=${TARGETARCH}${TARGETVARIANT} \
-  --var version=0.12.2 --var app=mc-monitor --file {{.app}} \
+  --var version=0.12.3 --var app=mc-monitor --file {{.app}} \
   --from https://github.com/itzg/{{.app}}/releases/download/{{.version}}/{{.app}}_{{.version}}_{{.os}}_{{.arch}}.tar.gz
 
 RUN easy-add --var os=${TARGETOS} --var arch=${TARGETARCH}${TARGETVARIANT} \
   --var version=1.9.0 --var app=mc-server-runner --file {{.app}} \
   --from https://github.com/itzg/{{.app}}/releases/download/{{.version}}/{{.app}}_{{.version}}_{{.os}}_{{.arch}}.tar.gz
 
-ARG MC_HELPER_VERSION=1.35.3
+ARG MC_HELPER_VERSION=1.36.1
 ARG MC_HELPER_BASE_URL=https://github.com/itzg/mc-image-helper/releases/download/${MC_HELPER_VERSION}
 # used for cache busting local copy of mc-image-helper
 ARG MC_HELPER_REV=1
@@ -61,9 +58,7 @@ ENV TYPE=VANILLA VERSION=LATEST EULA="" UID=1000 GID=1000
 COPY --chmod=755 scripts/start* /
 COPY --chmod=755 bin/ /usr/local/bin/
 COPY --chmod=755 bin/mc-health /health.sh
-COPY --chmod=644 files/log4j2.xml /image/log4j2.xml
+COPY --chmod=644 files/* /image/
-# By default this file gets retrieved from repo, but bundle in image as potential fallback
-COPY --chmod=644 files/cf-exclude-include.json /image/cf-exclude-include.json
 COPY --chmod=755 files/auto /auto
 
 RUN curl -fsSL -o /image/Log4jPatcher.jar https://github.com/CreeperHost/Log4jPatcher/releases/download/v1.0.1/Log4jPatcher-1.0.1.jar

build/alpine/install-packages.sh

@@ -26,9 +26,12 @@ apk add --no-cache -U \
     zstd \
     nfs-utils \
     libpcap \
-    libwebp
+    libwebp \
+    libcap
 
 # Patched knockd
 curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-alpine-amd64.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
+setcap cap_net_raw=ep /usr/local/sbin/knockd
+chown minecraft /usr/local/sbin/knockd

build/ol/install-packages.sh

@@ -46,3 +46,5 @@ bash /build/ol/install-gosu.sh
 curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
+setcap cap_net_raw=ep /usr/local/sbin/knockd
+chown minecraft /usr/local/sbin/knockd

build/ubuntu/install-packages.sh

@@ -35,4 +35,6 @@ apt-get clean
 curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
+setcap cap_net_raw=ep /usr/local/sbin/knockd
+chown minecraft /usr/local/sbin/knockd
 find /usr/lib -name 'libpcap.so.0.8' -execdir cp '{}' libpcap.so.1 \;

docs/configuration/server-properties.md

@@ -353,10 +353,28 @@ If you must, the server port can be set like:
 
 **however**, be sure to change your port mapping accordingly and be prepared for some features to break.
 
+### Custom server properties
+
+Some mods/plugins utilize custom `server.properties` entries which can be declared via the `CUSTOM_SERVER_PROPERTIES` environment variable. The contents must be newline delimited `name=value` pairs.
+
+Within a compose file, newline delimited entries can be declared as shown here:
+
+```yaml
+      CUSTOM_SERVER_PROPERTIES: |
+        custom1=value1
+        defaultworldgenerator-port=f8c04631-f744-11ec-b260-f02f74b094e0
+```
+
+When using `docker run` from a bash shell, the entries must be quoted with the `$'` syntax, such as
+
+```
+-e CUSTOM_SERVER_PROPERTIES=$'k1=v1\nk2=v2'
+```
+
 ### Other server property mappings
 
 | Environment Variable              | Server Property                   |
-| --------------------------------- | --------------------------------- |
+|-----------------------------------|-----------------------------------|
 | BROADCAST_CONSOLE_TO_OPS          | broadcast-console-to-ops          |
 | BROADCAST_RCON_TO_OPS             | broadcast-rcon-to-ops             |
 | ENABLE_STATUS                     | enable-status                     |

docs/misc/autopause-autostop/autopause.md

@@ -38,6 +38,8 @@ The following environment variables define the behaviour of auto-pausing:
   describes period of the daemonized state machine, that handles the pausing of the process (resuming is done independently)
 - `AUTOPAUSE_KNOCK_INTERFACE`, default `eth0`
   <br>Describes the interface passed to the `knockd` daemon. If the default interface does not work, run the `ifconfig` command inside the container and derive the interface receiving the incoming connection from its output. The passed interface must exist inside the container. Using the loopback interface (`lo`) does likely not yield the desired results.
+- `AUTOPAUSE_SUDO`, default "true"
+  specifies if the knockd service should be run via sudo in order to elevate its privileges
 
 !!! tip
 

docs/types-and-platforms/server-types/forge.md

@@ -35,3 +35,23 @@ In both of the cases above, there is no need for the `VERSION` or `FORGE_VERSION
 !!! note
 
     If an error occurred while installing Forge, it might be possible to resolve by temporarily setting `FORGE_FORCE_REINSTALL` to "true". Be sure to remove that variable after successfully starting the server.
+
+## Alternatives
+
+### NeoForge
+
+Support for [NeoForge](https://neoforged.net/) is also provided. A NeoForge server can be automatically managed by setting `TYPE` to "NEOFORGE". `VERSION` specifies the Minecraft version and `NEOFORGE_VERSION` can be set to select a specific sub-version. By default, the latest NeoForge version available for the requested Minecraft version will be used.
+
+!!! example
+
+    ```
+    docker run -e TYPE=NEOFORGE -e VERSION=1.20.1 -e NEOFORGE_VERSION=47.1.79 ...
+    ```
+    
+    or in a compose file
+    ```yaml
+        environment:
+          TYPE: NEOFORGE
+          VERSION: "1.20.1"
+          NEOFORGE_VERSION: "47.1.79"
+    ```

docs/versions/java.md

@@ -32,7 +32,7 @@ When using the image `itzg/minecraft-server` without a tag, the `latest` image t
 | java17-alpine    | 17           | Alpine | Hotspot        | amd64             |
 | java20-alpine    | 20           | Alpine | Hotspot        | amd64             |
 | java20           | 20           | Ubuntu | Hotspot        | amd64,arm64       |
-| java20-graalvm   | 20           | Oracle | Oracle GraalVM | amd64,arm64       |   
+| java21-graalvm   | 21           | Oracle | Oracle GraalVM | amd64,arm64       |   
 
 For example, to use Java version 8 on any supported architecture:
 
@@ -55,3 +55,4 @@ The following image tags have been deprecated and are no longer receiving update
 - multiarch-latest
 - java16/java16-openj9
 - java17-graalvm-ce
+- java20-graalvm

files/auto/autopause-daemon.sh

@@ -45,7 +45,11 @@ if isTrue "${DEBUG_AUTOPAUSE}"; then
   knockdArgs+=(-D)
 fi
 
-sudo /usr/local/sbin/knockd "${knockdArgs[@]}"
+if isTrue "${AUTOPAUSE_SUDO:-true}"; then
+  sudo /usr/local/sbin/knockd "${knockdArgs[@]}"
+else
+  /usr/local/sbin/knockd "${knockdArgs[@]}"
+fi
 if [ $? -ne 0 ] ; then
   logAutopause "Failed to start knockd daemon."
   logAutopause "Probable cause: Unable to attach to interface \"$AUTOPAUSE_KNOCK_INTERFACE\"."

files/property-definitions.json

@@ -0,0 +1,58 @@
+{
+  "motd": {"env": "MOTD"},
+  "gamemode": {"env": "MODE"},
+  "difficulty": {"env": "DIFFICULTY"},
+  "white-list": {"env": "WHITELIST_PROP"},
+  "enforce-whitelist": {"env": "ENFORCE_WHITELIST"},
+  "level-type": {"env": "LEVEL_TYPE"},
+  "server-name": {"env": "SERVER_NAME"},
+  "server-ip": {"env": "SERVER_IP"},
+  "server-port": {"env": "SERVER_PORT"},
+  "allow-nether": {"env": "ALLOW_NETHER"},
+  "announce-player-achievements": {"env": "ANNOUNCE_PLAYER_ACHIEVEMENTS"},
+  "enable-command-block": {"env": "ENABLE_COMMAND_BLOCK"},
+  "spawn-animals": {"env": "SPAWN_ANIMALS"},
+  "spawn-monsters": {"env": "SPAWN_MONSTERS"},
+  "spawn-npcs": {"env": "SPAWN_NPCS"},
+  "spawn-protection": {"env": "SPAWN_PROTECTION"},
+  "generate-structures": {"env": "GENERATE_STRUCTURES"},
+  "view-distance": {"env": "VIEW_DISTANCE"},
+  "hardcore": {"env": "HARDCORE"},
+  "snooper-enabled": {"env": "SNOOPER_ENABLED"},
+  "max-build-height": {"env": "MAX_BUILD_HEIGHT"},
+  "force-gamemode": {"env": "FORCE_GAMEMODE"},
+  "max-tick-time": {"env": "MAX_TICK_TIME"},
+  "enable-query": {"env": "ENABLE_QUERY"},
+  "query.port": {"env": "QUERY_PORT"},
+  "enable-rcon": {"env": "ENABLE_RCON"},
+  "rcon.password": {"env": "RCON_PASSWORD"},
+  "rcon.port": {"env": "RCON_PORT"},
+  "max-players": {"env": "MAX_PLAYERS"},
+  "max-world-size": {"env": "MAX_WORLD_SIZE"},
+  "level-name": {"env": "LEVEL"},
+  "level-seed": {"env": "SEED"},
+  "pvp": {"env": "PVP"},
+  "generator-settings": {"env": "GENERATOR_SETTINGS"},
+  "online-mode": {"env": "ONLINE_MODE"},
+  "allow-flight": {"env": "ALLOW_FLIGHT"},
+  "resource-pack": {"env": "RESOURCE_PACK"},
+  "resource-pack-sha1": {"env": "RESOURCE_PACK_SHA1"},
+  "require-resource-pack": {"env": "RESOURCE_PACK_ENFORCE"},
+  "player-idle-timeout": {"env": "PLAYER_IDLE_TIMEOUT"},
+  "broadcast-console-to-ops": {"env": "BROADCAST_CONSOLE_TO_OPS"},
+  "broadcast-rcon-to-ops": {"env": "BROADCAST_RCON_TO_OPS"},
+  "enable-jmx-monitoring": {"env": "ENABLE_JMX"},
+  "sync-chunk-writes": {"env": "SYNC_CHUNK_WRITES"},
+  "enable-status": {"env": "ENABLE_STATUS"},
+  "entity-broadcast-range-percentage": {"env": "ENTITY_BROADCAST_RANGE_PERCENTAGE"},
+  "function-permission-level": {"env": "FUNCTION_PERMISSION_LEVEL"},
+  "network-compression-threshold": {"env": "NETWORK_COMPRESSION_THRESHOLD"},
+  "op-permission-level": {"env": "OP_PERMISSION_LEVEL"},
+  "prevent-proxy-connections": {"env": "PREVENT_PROXY_CONNECTIONS"},
+  "use-native-transport": {"env": "USE_NATIVE_TRANSPORT"},
+  "simulation-distance": {"env": "SIMULATION_DISTANCE"},
+  "previews-chat": {"env": "PREVIEWS_CHAT"},
+  "enforce-secure-profile": {"env": "ENFORCE_SECURE_PROFILE"},
+  "initial-enabled-packs": {"env": "INITIAL_ENABLED_PACKS"},
+  "initial-disabled-packs": {"env": "INITIAL_DISABLED_PACKS"}
+}

scripts/start-configuration

@@ -185,6 +185,10 @@ case "${TYPE^^}" in
     exec "${SCRIPTS:-/}start-deployForge" "$@"
   ;;
 
+  NEOFORGE|NEOFORGED)
+    exec "${SCRIPTS:-/}start-deployNeoForge" "$@"
+  ;;
+
   FABRIC)
     exec "${SCRIPTS:-/}start-deployFabric" "$@"
   ;;

scripts/start-deployNeoForge

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+: "${NEOFORGE_VERSION:=latest}"
+: "${NEOFORGE_FORCE_REINSTALL:=false}}"
+
+# shellcheck source=start-utils
+. "${SCRIPTS:-$(dirname "$0")}/start-utils"
+isDebugging && set -x
+
+resultsFile=/data/.run-neoforge.env
+
+if ! mc-image-helper install-neoforge \
+  --output-directory=/data \
+  --results-file=${resultsFile} \
+  --minecraft-version="${VERSION}" \
+  --neoforge-version="${NEOFORGE_VERSION}" \
+  --force-reinstall="${NEOFORGE_FORCE_REINSTALL}"; then
+    log "ERROR failed to install Forge"
+    exit 1
+fi
+
+# grab SERVER and export it
+set -a
+# shellcheck disable=SC1090
+source ${resultsFile}
+set +a
+
+export FAMILY=FORGE
+
+exec "${SCRIPTS:-/}start-setupWorld" "$@"

scripts/start-setupServerProperties

@@ -8,49 +8,18 @@
 : "${SKIP_SERVER_PROPERTIES:=false}"
 : "${ENABLE_WHITELIST:=}"
 
-# FUNCTIONS
-function setServerPropValue {
-  local prop=$1
-  local value=$2
-  # normalize booleans
-  case ${value^^} in
-    TRUE|FALSE)
-      value=${value,,} ;;
-  esac
-  if [[ $prop =~ password ]]; then
-    showValue="*****"
-  else
-    showValue="$value"
-  fi
-  if [ -f "$SERVER_PROPERTIES" ] && grep "${prop}" "$SERVER_PROPERTIES" > /dev/null; then
-    debug "Setting ${prop} to '${showValue}' in ${SERVER_PROPERTIES}"
-    sed -i "/^${prop}\s*=/ c ${prop}=${value//\\/\\\\}" "$SERVER_PROPERTIES"
-  else
-    debug "Adding ${prop} with '${showValue}' in ${SERVER_PROPERTIES}"
-    echo "${prop}=${value}" >> "$SERVER_PROPERTIES"
-  fi
-}
-
-function setServerProp {
-  local prop=$1
-  local varName=$2
-
-  if [ -v $varName ]; then
-    setServerPropValue "$prop" "${!varName}"
-  fi
-}
-
 function customizeServerProps {
   local firstSetup=$1
   # Whitelist processing
   if [ -n "$WHITELIST" ] || [ -n "$WHITELIST_FILE" ] || isTrue "${ENABLE_WHITELIST}"; then
     log "Enabling whitelist functionality"
-    setServerPropValue "white-list" "true"
+    WHITELIST_PROP=true
-    setServerPropValue "enforce-whitelist" "true"
+    ENFORCE_WHITELIST=true
+    export WHITELIST_PROP ENFORCE_WHITELIST
   elif isTrue "$firstSetup" || isFalse "${ENABLE_WHITELIST}"; then
     log "Disabling whitelist functionality"
-    setServerPropValue "white-list" "false"
+    WHITELIST_PROP=false
-    setServerProp "enforce-whitelist" ENFORCE_WHITELIST
+    export WHITELIST_PROP
   fi
 
   # normalize MOTD
@@ -59,101 +28,11 @@ function customizeServerProps {
       MOTD="{\"text\":\"${MOTD}\"}"
     fi
   fi
-
-  setServerProp "server-name" SERVER_NAME
-  setServerProp "server-ip" SERVER_IP
-  setServerProp "server-port" SERVER_PORT
-  setServerProp "allow-nether" ALLOW_NETHER
-  setServerProp "announce-player-achievements" ANNOUNCE_PLAYER_ACHIEVEMENTS
-  setServerProp "enable-command-block" ENABLE_COMMAND_BLOCK
-  setServerProp "spawn-animals" SPAWN_ANIMALS
-  setServerProp "spawn-monsters" SPAWN_MONSTERS
-  setServerProp "spawn-npcs" SPAWN_NPCS
-  setServerProp "spawn-protection" SPAWN_PROTECTION
-  setServerProp "generate-structures" GENERATE_STRUCTURES
-  setServerProp "view-distance" VIEW_DISTANCE
-  setServerProp "hardcore" HARDCORE
-  setServerProp "snooper-enabled" SNOOPER_ENABLED
-  setServerProp "max-build-height" MAX_BUILD_HEIGHT
-  setServerProp "force-gamemode" FORCE_GAMEMODE
-  setServerProp "max-tick-time" MAX_TICK_TIME
-  setServerProp "enable-query" ENABLE_QUERY
-  setServerProp "query.port" QUERY_PORT
-  setServerProp "enable-rcon" ENABLE_RCON
-  setServerProp "rcon.password" RCON_PASSWORD
-  setServerProp "rcon.port" RCON_PORT
-  setServerProp "max-players" MAX_PLAYERS
-  setServerProp "max-world-size" MAX_WORLD_SIZE
-  setServerProp "level-name" LEVEL
-  setServerProp "level-seed" SEED
-  setServerProp "pvp" PVP
-  setServerProp "generator-settings" GENERATOR_SETTINGS
-  setServerProp "online-mode" ONLINE_MODE
-  setServerProp "allow-flight" ALLOW_FLIGHT
-  setServerProp "resource-pack" RESOURCE_PACK
-  setServerProp "resource-pack-sha1" RESOURCE_PACK_SHA1
-  setServerProp "require-resource-pack" RESOURCE_PACK_ENFORCE
-  setServerProp "player-idle-timeout" PLAYER_IDLE_TIMEOUT
-  setServerProp "broadcast-console-to-ops" BROADCAST_CONSOLE_TO_OPS
-  setServerProp "broadcast-rcon-to-ops" BROADCAST_RCON_TO_OPS
-  setServerProp "enable-jmx-monitoring" ENABLE_JMX
-  setServerProp "sync-chunk-writes" SYNC_CHUNK_WRITES
-  setServerProp "enable-status" ENABLE_STATUS
-  setServerProp "entity-broadcast-range-percentage" ENTITY_BROADCAST_RANGE_PERCENTAGE
-  setServerProp "function-permission-level" FUNCTION_PERMISSION_LEVEL
-  setServerProp "network-compression-threshold" NETWORK_COMPRESSION_THRESHOLD
-  setServerProp "op-permission-level" OP_PERMISSION_LEVEL
-  setServerProp "prevent-proxy-connections" PREVENT_PROXY_CONNECTIONS
-  setServerProp "use-native-transport" USE_NATIVE_TRANSPORT
-  setServerProp "simulation-distance" SIMULATION_DISTANCE
-  setServerProp "previews-chat" PREVIEWS_CHAT
-  setServerProp "enforce-secure-profile" ENFORCE_SECURE_PROFILE
-  setServerProp "initial-enabled-packs" INITIAL_ENABLED_PACKS
-  setServerProp "initial-disabled-packs" INITIAL_DISABLED_PACKS
   if [[ $MOTD ]]; then
-    setServerPropValue "motd" "$(echo "$MOTD" | mc-image-helper asciify)"
+    MOTD="$(echo "$MOTD" | mc-image-helper asciify)"
-  fi
-  [[ $LEVEL_TYPE ]] && setServerPropValue "level-type" "${LEVEL_TYPE^^}"
-
-  if [ -n "$DIFFICULTY" ]; then
-    case ${DIFFICULTY,,} in
-      peaceful|0)
-        if versionLessThan 1.13; then
-          DIFFICULTY=0
-        else
-          DIFFICULTY=peaceful
-        fi
-        ;;
-      easy|1)
-        if versionLessThan 1.13; then
-          DIFFICULTY=1
-        else
-          DIFFICULTY=easy
-        fi
-        ;;
-      normal|2)
-        if versionLessThan 1.13; then
-          DIFFICULTY=2
-        else
-          DIFFICULTY=normal
-        fi
-        ;;
-      hard|3)
-        if versionLessThan 1.13; then
-          DIFFICULTY=3
-        else
-          DIFFICULTY=hard
-        fi
-        ;;
-      *)
-        log "DIFFICULTY must be peaceful, easy, normal, or hard."
-        exit 1
-        ;;
-    esac
-    setServerPropValue "difficulty" "$DIFFICULTY"
   fi
 
-  if [ -n "$MODE" ]; then
+  if [[ -v MODE ]]; then
     log "Setting mode"
     case ${MODE,,} in
       su*|0)
@@ -189,8 +68,58 @@ function customizeServerProps {
         exit 1
         ;;
     esac
-    setServerPropValue "gamemode" "$MODE"
   fi
+
+  if [[ -v DIFFICULTY ]]; then
+    case ${DIFFICULTY,,} in
+      peaceful|0)
+        if versionLessThan 1.13; then
+          DIFFICULTY=0
+        else
+          DIFFICULTY=peaceful
+        fi
+        ;;
+      easy|1)
+        if versionLessThan 1.13; then
+          DIFFICULTY=1
+        else
+          DIFFICULTY=easy
+        fi
+        ;;
+      normal|2)
+        if versionLessThan 1.13; then
+          DIFFICULTY=2
+        else
+          DIFFICULTY=normal
+        fi
+        ;;
+      hard|3)
+        if versionLessThan 1.13; then
+          DIFFICULTY=3
+        else
+          DIFFICULTY=hard
+        fi
+        ;;
+      *)
+        log "DIFFICULTY must be peaceful, easy, normal, or hard."
+        exit 1
+        ;;
+    esac
+  fi
+
+  if [[ -v LEVEL_TYPE ]]; then
+    LEVEL_TYPE="${LEVEL_TYPE^^}"
+  fi
+
+  setPropertiesArgs=(
+    --definitions "/image/property-definitions.json"
+  )
+  if [[ -v CUSTOM_SERVER_PROPERTIES ]]; then
+    setPropertiesArgs+=(--custom-properties "$CUSTOM_SERVER_PROPERTIES")
+  fi
+
+  mc-image-helper set-properties "${setPropertiesArgs[@]}" "$SERVER_PROPERTIES"
+
 }
 
 # Deploy server.properties file