solr: Automatically determine java memory limits

solr/manifests/init.pp

@@ -122,7 +122,7 @@ class solr {
         mode    => "0755",
         owner   => "root",
         group   => "root",
-        source => "puppet:///modules/solr/solr.init",
+        content => template("solr/solr.init.erb"),
         notify  => Exec["add-service-solr"],
     }
     exec { "add-service-solr":

solr/templates/solr.init.erb

@@ -1,3 +1,14 @@
+<%
+mem, unit = @memorysize.split
+case unit
+when "GB"
+    mem = mem.to_i * 1024
+else
+    mem = mem.to_i
+end
+heapmin = (mem * 0.15).to_i
+heapmax = (mem * 0.85).to_i
+-%>
 #!/bin/sh
 
 # chkconfig: 2345 95 05
@@ -19,7 +30,7 @@ SOLRUSER="solr"
 RUNDIR="/srv/solr/run"
 HOMEDIR="/srv/solr/cores"
 LOG4JCONFIG="file:///${RUNDIR}/resources/log4j.properties"
-MEMORYLIMIT="-Xms1024M -Xmx4096M"
+MEMORYLIMIT="-Xms<%= heapmin %>M -Xmx<%= heapmax %>M"
 
 if [ `id -u` != "0" ]; then
     echo "This script must be run with root privileges." && exit 1