From cf1386628e724b4fac7b7279c8ded4de0812ed6b Mon Sep 17 00:00:00 2001
From: JeremyStarTM <jeremystartm@staropensource.de>
Date: Wed, 10 Jul 2024 12:35:59 +0200
Subject: [PATCH] Add custom JVM support

---
 config.example.env |  5 +++++
 docker-compose.yml |  1 +
 entrypoint.sh      | 15 +++++++++++++--
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/config.example.env b/config.example.env
index 0d14832..2646e55 100644
--- a/config.example.env
+++ b/config.example.env
@@ -47,6 +47,11 @@ MCSD_MEMORY_MIN=2048M
 ## >= 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 $JAVA_HOME
+MCSD_JAVA_CUSTOM=false
+
 # OPTIMIZED_FLAGS
 ## Applies a modified variant of Aikar's Flags
 MCSD_OPTIMIZED_FLAGS=true
diff --git a/docker-compose.yml b/docker-compose.yml
index ffb86c6..340f722 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -6,6 +6,7 @@ services:
   stop_grace_period: 120s
   volumes:
    - ./server:/data
+   - ./jvm:/jvm
   env_file:
    - ./config.env
   ports:
diff --git a/entrypoint.sh b/entrypoint.sh
index d7f7e97..1e17540 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -75,6 +75,11 @@ function initialize() {
     echo ":: Warning: No/Invalid java version supplied to \$MCSD_JAVA_VERSION, defaulting to java version 17"
     export "MCSD_JAVA_VERSION=17"
   fi
+  # Java custom JVM
+  if [ ! "${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")
@@ -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