Fix for chroot not getting supliemental groups

Fixes #1398

Author: coolacid

pkg/logstash.sysv

@@ -50,11 +50,15 @@ start() {
   HOME=${LS_HOME}
   export PATH HOME LS_HEAP_SIZE LS_JAVA_OPTS LS_USE_GC_LOGGING
 
+  # chown doesn't grab the suplimental groups when setting the user:group - so we have to do it for it.
+  # Boy, I hope we're root here. 
+  SGROUPS=$(grep "$LS_USER" /etc/group | grep -v "^$LS_GROUP" | cut -d: -f1 | tr "\\n" "," | sed 's/,$//'; echo '')
+
   # set ulimit as (root, presumably) first, before we drop privileges
   ulimit -n ${LS_OPEN_FILES}
 
   # Run the program!
-  nice -n ${LS_NICE} chroot --userspec $LS_USER:$LS_GROUP / sh -c "
+  nice -n ${LS_NICE} chroot --userspec $LS_USER:$LS_GROUP --groups $SGROUPS / sh -c "
     cd $LS_HOME
     ulimit -n ${LS_OPEN_FILES}
     exec \"$program\" $args