Merged latest from master

#819

Dockerfile

@@ -1,11 +1,10 @@
-FROM ubuntu:18.04
+FROM adoptopenjdk:15-jre
 
 LABEL org.opencontainers.image.authors="Geoff Bourne <itzgeoff@gmail.com>"
 
 RUN apt-get update \
   && DEBIAN_FRONTEND=noninteractive \
   apt-get install -y \
-    openjdk-8-jre-headless \
     imagemagick \
     gosu \
     sudo \

README.md

@@ -327,10 +327,6 @@ An [Airplane](https://github.com/TECHNOVE/Airplane) server, which is a fork of T
 
 > **NOTE** only Java 8 and 11 are supported
 
-Extra variables:
-- `FORCE_REDOWNLOAD=false` : set to true to force the located server jar to be re-downloaded
-- `USE_FLARE_FLAGS=false` : set to true to add appropriate flags for the [Flare](https://blog.airplane.gg/flare) profiler
-
 ## Running a Purpur server
 
 A [Purpur](https://purpur.pl3x.net/) server, which is "a fork of Paper, Tuinity, Airplane with the goal of providing new and interesting configuration options".
@@ -342,7 +338,6 @@ A [Purpur](https://purpur.pl3x.net/) server, which is "a fork of Paper, Tuinity,
 Extra variables:
 - `PURPUR_BUILD=LATEST` : set a specific Purpur build to use
 - `FORCE_REDOWNLOAD=false` : set to true to force the located server jar to be re-downloaded
-- `USE_FLARE_FLAGS=false` : set to true to add appropriate flags for the [Flare](https://blog.airplane.gg/flare) profiler
 
 ## Running a Yatopia server
 
@@ -355,7 +350,6 @@ A [Yatopia](https://github.com/YatopiaMC/Yatopia) server, which is a "blazing fa
 Extra variables:
 - `RELEASE=stable` : set to `stable` or `latest`
 - `FORCE_REDOWNLOAD=false` : set to true to force the located server jar to be re-downloaded
-- `USE_FLARE_FLAGS=false` : set to true to add appropriate flags for the [Flare](https://blog.airplane.gg/flare) profiler
 
 ## Running a Magma server
 

start-configuration

@@ -56,7 +56,7 @@ fi
 
 if ! which java > /dev/null; then
   log "Fixing PATH to include java"
-  PATH="${PATH}:/usr/bin"
+  PATH="${PATH}:/opt/java/openjdk/bin"
 fi
 
 export VERSIONS_JSON=https://launchermeta.mojang.com/mc/game/version_manifest.json
@@ -98,6 +98,12 @@ case "${TYPE^^}" in
   ;;
 
   FORGE)
+    log "**********************************************************************"
+    log "WARNING: The image tag itzg/minecraft-server:java8 is recommended"
+    log "         since some mods require Java 8"
+    log "         Exception traces reporting ClassCastException: class jdk.internal.loader.ClassLoaders\$AppClassLoader"
+    log "         can be fixed with java8"
+    log "**********************************************************************"
     exec ${SCRIPTS:-/}start-deployForge "$@"
   ;;
 
@@ -109,7 +115,13 @@ case "${TYPE^^}" in
     exec ${SCRIPTS:-/}start-deployFTBA "$@"
   ;;
 
-  CURSEFORGE|FTB)
+  FTB|CURSEFORGE)
+    log "**********************************************************************"
+    log "WARNING: The image tag itzg/minecraft-server:java8 is recommended"
+    log "         since some mods require Java 8"
+    log "         Exception traces reporting ClassCastException: class jdk.internal.loader.ClassLoaders\$AppClassLoader"
+    log "         can be fixed with java8"
+    log "**********************************************************************"
     exec ${SCRIPTS:-/}start-deployCF "$@"
   ;;
 

start-deployAirplane

@@ -19,7 +19,7 @@ fi
 
 export SERVER=airplane-${VANILLA_VERSION}-jdk${JAVA_VER}.jar
 
-if [ ! -f "$SERVER" ] || isTrue "$FORCE_REDOWNLOAD"; then
+if [ ! -f "$SERVER" ] || [ -n "$FORCE_REDOWNLOAD" ]; then
     downloadUrl="https://dl.airplane.gg/latest/Airplane-JDK${JAVA_VER}/launcher-airplane.jar"
     log "Downloading Airplane from $downloadUrl ..."
     curl -fsSL -o "$SERVER" "$downloadUrl"

start-minecraftFinalSetup

@@ -144,13 +144,6 @@ if isTrue "${USE_LARGE_PAGES}"; then
   "
 fi
 
-if isTrue "${USE_FLARE_FLAGS}"; then
-  JVM_XX_OPTS="${JVM_XX_OPTS}
-  -XX:+UnlockDiagnosticVMOptions
-  -XX:+DebugNonSafepoints
-  "
-fi
-
 if isTrue "${DEBUG_MEMORY}"; then
   log "Memory usage and availability (in MB)"
   uname -a