Merge pull request #275 from mediaessenz/feature/add-jvm-dd-opts

[Feature] add JVM_DD_OPTS

minecraft-server/README.md

@@ -769,6 +769,9 @@ General JVM options can be passed to the Minecraft Server invocation by passing
 environment variable. Options like `-X` that need to proceed general JVM options can be passed
 via a `JVM_XX_OPTS` environment variable.
 
+For some cases, if e.g. after removing mods, it could be necessary to startup minecraft with an additional `-D` parameter like `-Dfml.queryResult=confirm`. To address this you can use the environment variable `JVM_DD_OPTS`, which builds the params from a given list of values separated by space, but without the `-D` prefix. To make things running under systems (e.g. Plesk), which doesn't allow `=` inside values, a `:` (colon) could be used instead. The upper example would look like this:
+`JVM_DD_OPTS=fml.queryResult:confirm`, and will be converted to `-Dfml.queryResult=confirm`. 
+
 ### HTTP Proxy
 
 You may configure the use of an HTTP/HTTPS proxy by passing the proxy's URL via the `PROXY`

minecraft-server/start-minecraftFinalSetup

@@ -99,6 +99,13 @@ else
   if [ -f /data/bootstrap.txt ]; then
     bootstrapArgs="--bootstrap /data/bootstrap.txt"
   fi
+  
+  if [ -n "$JVM_DD_OPTS" ]; then
+        for dopt in $JVM_DD_OPTS
+        do
+            JVM_OPTS="${JVM_OPTS} -D${dopt/:/=}"
+        done
+  fi
 
   JVM_OPTS="-Xms${INIT_MEMORY} -Xmx${MAX_MEMORY} ${JVM_OPTS}"
   exec mc-server-runner ${bootstrapArgs} java $JVM_XX_OPTS $JVM_OPTS -jar $SERVER "$@" $EXTRA_ARGS