Update entrypoint.sh

- Add comments
- Move argument compiler from initialize() into compile_args()
- Add compile_flags() function
- Add internal_error() function
- Move several functions
- Move log cleaning into own function
- Support for Aikar's flags (better variant)
- Support for G1GC and ZGC garbage collectors
- Support for manipulating memory limits

entrypoint.sh

@@ -2,6 +2,33 @@
 # Disables warning about echo not expanding escape sequences
 # shellcheck disable=SC2028
 
+# Used for internal errors
+function internal_error() {
+  echo "-> INTERNAL ERROR: ${*}"
+  exit 99
+}
+
+# Automatically accepts the End User License Agreement
+function accept_eula() {
+  echo "eula=true" > /data/eula.txt
+}
+
+# Cleans /logs and /crash-reports
+function clean_logs() {
+  if [ "${MCSD_CLEAN_LOGS}" == "true" ]; then
+    rm -rf "/data/logs" "/data/crash-reports"
+  fi
+}
+
+# Used by trap, shuts the server down
+function kill_server() {
+  if [ -z "${CHILDPID}" ]; then
+    internal_error "\$CHILDPID is unset"
+  fi
+  kill -SIGINT "${CHILDPID}"
+}
+
+# Print the MCSD banner
 function print_banner() {
   echo "         ____     ____                                          ____                    __"
   echo " /'\\_/\`\\/\\  _\`\\  /\\  _\`\\                                       /\\  _\`\\                 /\\ \\"
@@ -12,18 +39,23 @@ function print_banner() {
   echo "   \\/_/ \\/_/\\/___/   \\/_____/\\/____/ \\/_/   \\/__/   \\/____/ \\/_/   \\/___/  \\/___/  \\/____/ \\/_/\\/_/\\/____/ \\/_/"
 }
 
+# Initialize MCSD
 function initialize() {
   echo ":: Initializing MCSD"
-  export "ARGS=--nogui "
+  # Server arguments
-  if [ -z "${MCSD_ENFORCE_FRESH_CACHES}" ]; then
+  if [ ! "${MCSD_ENFORCE_FRESH_CACHES}" == "true" ] && [ ! "${MCSD_ENFORCE_FRESH_CACHES}" == "false" ]; then
-    export "ARGS=${ARGS}--eraseCache "
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_ENFORCE_FRESH_CACHES, defaulting to false"
+    export "MCSD_ENFORCE_FRESH_CACHES=false"
   fi
-  if [ -z "${MCSD_FORCE_UPGRADE}" ]; then
+  if [ ! "${MCSD_FORCE_UPGRADE}" == "true" ] && [ ! "${MCSD_FORCE_UPGRADE}" == "false" ]; then
-    export "ARGS=${ARGS}--forceUpgrade "
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_FORCE_UPGRADE, defaulting to true"
+    export "MCSD_FORCE_UPGRADE=true"
   fi
-  if [ -z "${MCSD_SAFEMODE}" ]; then
+  if [ ! "${MCSD_SAFEMODE}" == "true" ] && [ ! "${MCSD_SAFEMODE}" == "false" ]; then
-    export "ARGS=${ARGS}--safeMode "
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_SAFEMODE, defaulting to false"
+    export "MCSD_SAFEMODE=false"
   fi
+  # MCSD functionality
   if [ ! "${MCSD_AUTO_RESTART}" == "true" ] && [ ! "${MCSD_AUTO_RESTART}" == "false" ]; then
     echo ":: Warning: No/Invalid value supplied to \$MCSD_AUTO_RESTART, defaulting to false"
     export "MCSD_AUTO_RESTART=false"
@@ -32,12 +64,32 @@ function initialize() {
     echo ":: Warning: No/Invalid value supplied to \$MCSD_CLEAN_LOGS, defaulting to false"
     export "MCSD_CLEAN_LOGS=false"
   fi
+  # Memory limits
+  if [ -n "${MCSD_MEMORY_MIN}" ]; then
+    echo ":: Error: No memory limit supplied to \$MCSD_MEMORY_MIN"
+    exit 1
+  fi
+  if [ -n "${MCSD_MEMORY_MAX}" ]; then
+    echo ":: Error: No memory limit supplied to \$MCSD_MEMORY_MAX"
+    exit 1
+  fi
+  # Java version
   if [ ! "${MCSD_JAVA_VERSION}" == "17" ] && [ ! "${MCSD_JAVA_VERSION}" == "11" ] && [ ! "${MCSD_JAVA_VERSION}" == "8" ]; then
     echo ":: Warning: No/Invalid java version supplied to \$MCSD_JAVA_VERSION, defaulting to java version 17"
     export "MCSD_JAVA_VERSION=17"
   fi
+  # Java optimization
+  if [ ! "${MCSD_OPTIMIZED_FLAGS}" == "true" ] && [ ! "${MCSD_OPTIMIZED_FLAGS}" == "false" ]; then
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_OPTIMIZED_FLAGS, defaulting to true"
+    export "MCSD_OPTIMIZED_FLAGS=true"
+  fi
+  if [ ! "${MCSD_GARBAGECOLLECTOR}" == "G1GC" ] && [ ! "${MCSD_GARBAGECOLLECTOR}" == "ZGC" ]; then
+    echo ":: Warning: No/Invalid value supplied to \$MCSD_GARBAGECOLLECTOR, defaulting to G1GC"
+    export "MCSD_GARBAGECOLLECTOR=G1GC"
+  fi
 }
 
+# Check for directories and files
 function check() {
   echo ":: Checking environment"
   if [ ! -d "/data" ]; then
@@ -50,27 +102,96 @@ function check() {
   fi
 }
 
-function accept_eula() {
+# Compile server arguments
-	echo "eula=true" > /data/eula.txt
+function compile_args() {
+  echo ":: Compiling server arguments"
+  export "ARGS=--nogui"
+  case "${MCSD_ENFORCE_FRESH_CACHES}" in
+    "true")
+      export "ARGS=${ARGS} --eraseCache"
+      ;;
+    "false") ;;
+    *)
+      internal_error "\$MCSD_ENFORCE_FRESH_CACHES has invalid value"
+      ;;
+  esac
+  case "${MCSD_FORCE_UPGRADE}" in
+    "true")
+      export "ARGS=${ARGS} --forceUpgrade"
+      ;;
+    "false") ;;
+    *)
+      internal_error "\$MCSD_FORCE_UPGRADE has invalid value"
+      ;;
+  esac
+  case "${MCSD_SAFEMODE}" in
+    "true")
+      export "ARGS=${ARGS} --safeMode"
+      ;;
+    "false") ;;
+    *)
+      internal_error "\$MCSD_SAFEMODE has invalid value"
+      ;;
+  esac
 }
 
-function kill_server() {
+# Compile java flags
-  kill -SIGINT "$CHILDPID"
+function compile_flags() {
+  echo ":: Compiling java flags"
+  export "FLAGS=-Xms${MCSD_MEMORY_MIN} -Xmx${MCSD_MEMORY_MAX}"
+  case "${MCSD_OPTIMIZED_FLAGS}" in
+    "true")
+      export "FLAGS=${FLAGS} -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+AlwaysActAsServerClassMachine -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:+UseNUMA -XX:NmethodSweepActivity=1 -XX:ReservedCodeCacheSize=400M -XX:NonNMethodCodeHeapSize=12M -XX:ProfiledCodeHeapSize=194M -XX:NonProfiledCodeHeapSize=194M -XX:-DontCompileHugeMethods -XX:MaxNodeLimit=240000 -XX:NodeLimitFudgeFactor=8000 -XX:+UseVectorCmov -XX:+PerfDisableSharedMem -XX:+UseFastUnorderedTimeStamps -XX:+UseCriticalJavaThreadPriority -XX:ThreadPriorityPolicy=1 -XX:AllocatePrefetchStyle=3"
+      ;;
+    "false") ;;
+    *)
+      internal_error "\$MCSD_OPTIMIZED_FLAGS has invalid value"
+      ;;
+  esac
+  case "${MCSD_GARBAGECOLLECTOR}" in
+    "G1GC")
+      export "FLAGS=${FLAGS} -XX:+UseG1GC -XX:MaxGCPauseMillis=130 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=28 -XX:G1HeapRegionSize=16M -XX:G1ReservePercent=20 -XX:G1MixedGCCountTarget=3 -XX:InitiatingHeapOccupancyPercent=10 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=0 -XX:SurvivorRatio=32 -XX:MaxTenuringThreshold=1 -XX:G1SATBBufferEnqueueingThresholdPercent=30 -XX:G1ConcMarkStepDurationMillis=5 -XX:G1ConcRSHotCardLimit=16 -XX:G1ConcRefinementServiceIntervalMillis=150"
+      ;;
+    "ZGC")
+      export "FLAGS=${FLAGS} -XX:+UseZGC -XX:AllocatePrefetchStyle=1 -XX:-ZProactive"
+      ;;
+    *)
+      internal_error "\$MCSD_GARBAGECOLLECTOR has invalid value"
+      ;;
+  esac
 }
 
+# Starts the server
 function run() {
   echo ":: Starting server"
   cd /data||exit 69
   # We want to use ${ARGS} without using parenthesis
   # shellcheck disable=SC2086
-  "/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk/bin/java" -jar "/data/server.jar" ${ARGS} &
+  "/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk/bin/java" ${FLAGS} -jar "/data/server.jar" ${ARGS} &
+  # Set server pid
   export "CHILDPID=${!}"
+  # Setup trap
   trap kill_server SIGTERM
   trap kill_server SIGINT
+  # Wait for server to end
   wait
+}
+
+# Need I say more?
+function main() {
+  print_banner
+  initialize
+  check
+  accept_eula
+  clean_logs
+  compile_args
+  compile_flags
+  # Run server once
+  run
+  # Restart server if enabled
   case "${MCSD_AUTO_RESTART}" in
     "true")
-      echo ":: Restarting server after shutdown"
+      echo ":: Restarting server"
       run
       ;;
     "false")
@@ -78,18 +199,9 @@ function run() {
       exit 0
       ;;
     *)
-      echo ":: An internal error occured (run function, can't decide MCSD_AUTO_RESTART)"
+      internal_error "\$MCSD_AUTO_RESTART has invalid value"
       ;;
   esac
 }
 
-function main() {
-  print_banner
-  initialize
-  check
-  accept_eula
-  if [ "${MCSD_CLEAN_LOGS}" == "true" ]; then rm -rf "/data/logs" "/data/crash-reports"; fi
-  run
-}
-
 main