Add custom JVM support

Dockerfile

@@ -29,7 +29,7 @@ LABEL org.opencontainers.image.licenses="GPL-3.0-only"
 RUN true
 RUN nice -20 apk update
 RUN nice -20 apk upgrade
-RUN nice -20 apk add bash libstdc++ openjdk21-jre openjdk17-jre openjdk11-jre
+RUN nice -20 apk add bash libstdc++ openjdk21-jre openjdk17-jre openjdk11-jre openjdk8-jre
 RUN mkdir /app
 ADD entrypoint.sh /app/entrypoint.sh
 COPY --from=builder /builder/bin/rcon /usr/bin/rcon

config.example.env

@@ -44,7 +44,13 @@ MCSD_MEMORY_MIN=2048M
 ## <= 1.16           | 8
 ## <= 1.16           | 11 (may increase performance)
 ## >= 1.17           | 17
-MCSD_JAVA_VERSION=17
+## >= 1.20.5         | 21
+MCSD_JAVA_VERSION=21
+
+# JAVA_CUSTOM
+## Set this to 'true' if you want to use a custom JVM
+## located at './jvm/'. This will update $JAVA_HOME
+MCSD_JAVA_CUSTOM=false
 
 # OPTIMIZED_FLAGS
 ## Applies a modified variant of Aikar's Flags

docker-compose.yml

@@ -6,6 +6,7 @@ services:
   stop_grace_period: 120s
   volumes:
    - ./server:/data
+   - ./jvm:/jvm
   env_file:
    - ./config.env
   ports:

entrypoint.sh

@@ -71,10 +71,15 @@ function initialize() {
     exit 1
   fi
   # Java version
-  if [ ! "${MCSD_JAVA_VERSION}" == "17" ] && [ ! "${MCSD_JAVA_VERSION}" == "11" ] && [ ! "${MCSD_JAVA_VERSION}" == "8" ]; then
+  if [ ! "${MCSD_JAVA_VERSION}" == "21" ] && [ ! "${MCSD_JAVA_VERSION}" == "17" ] && [ ! "${MCSD_JAVA_VERSION}" == "11" ] && [ ! "${MCSD_JAVA_VERSION}" == "8" ]; then
     echo ":: Warning: No/Invalid java version supplied to \$MCSD_JAVA_VERSION, defaulting to java version 17"
     export "MCSD_JAVA_VERSION=17"
   fi
+  # Java custom JVM
+  if [ ! "${MCSD_JAVA_CUSTOM}" == "true" ] && [ ! "${MCSD_JAVA_CUSTOM}" == "false" ]; then
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_JAVA_CUSTOM, defaulting to false"
+    export "MCSD_JAVA_CUSTOM=false"
+  fi
   # Java optimization
   if [ ! "${MCSD_OPTIMIZED_FLAGS}" == "true" ] && [ ! "${MCSD_OPTIMIZED_FLAGS}" == "false" ]; then
     echo ":: Warning: No/Invalid value supplied to \$MCSD_OPTIMIZED_FLAGS, defaulting to true"
@@ -135,6 +140,12 @@ function compile_args() {
 # Compile java flags
 function compile_flags() {
   echo ":: Compiling java flags"
+  if [ "${MCSD_JAVA_CUSTOM}" == "true" ]; then
+    export "JAVA_HOME=/jvm"
+  else
+    export "JAVA_HOME=/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk"
+  fi
+  
   export "FLAGS=-Xms${MCSD_MEMORY_MIN} -Xmx${MCSD_MEMORY_MAX}"
   case "${MCSD_OPTIMIZED_FLAGS}" in
     "true")
@@ -156,7 +167,7 @@ function compile_flags() {
       internal_error "\$MCSD_GARBAGECOLLECTOR has invalid value"
       ;;
   esac
-  if [ "${MCSD_JAVA_VERSION}" == "17" ]; then
+  if [ "${MCSD_JAVA_VERSION}" == "17" ] || [ "${MCSD_JAVA_VERSION}" == "21" ]; then
 	export "FLAGS=${FLAGS} --add-modules=jdk.incubator.vector"
   fi
 }
@@ -172,7 +183,7 @@ compile_flags
 echo ":: Starting server"
 cd /data||exit 69
 if [ -z "${MCSD_CUSTOM_ARGS}" ]; then
-	exec "/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk/bin/java" ${FLAGS} -jar "/data/server.jar" ${ARGS}
+  exec "${JAVA_HOME}/bin/java" ${FLAGS} -jar "/data/server.jar" ${ARGS}
 else
-	exec "/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk/bin/java" ${MCSD_CUSTOM_ARGS} -jar "/data/server.jar" ${ARGS}
+  exec "${JAVA_HOME}/bin/java" ${MCSD_CUSTOM_ARGS} -jar "/data/server.jar" ${ARGS}
 fi