XDOCKER-51: Expose configuration options to configure an XWiki cluster

* Edited the sed command to replace Examples

.gitignore

@@ -39,3 +39,4 @@ nbproject
 .sonar-ide.properties
 .clover
 *~
+.DS_Store

template/xwiki/docker-entrypoint.sh

@@ -39,6 +39,11 @@ function other_starts() {
 function xwiki_replace() {
   sed -i s~"\\#\\? \\?\$2 \\?=.*"~"\$2=\$3"~g "\$1"
 }
+# \$1 - the setting/property to set
+# \$2 - the new value
+function xwiki_replace_example() {
+  sed -i s~"\#-# Example:\? \?$1 \?=.*"~"$1=$2"~g "/usr/local/tomcat/webapps/ROOT/WEB-INF/xwiki.properties"
+}
 
 # \$1 - the setting/property to set
 # \$2 - the new value
@@ -109,9 +114,9 @@ function enableClustering() {
   xwiki_set_properties 'observation.remote.enabled' 'true'
   if [ \$CLUSTER_CHANNEL ]; then
     echo "Setting cluster channel to \$CLUSTER_CHANNEL"
-    xwiki_set_properties 'observation.remote.channels' "\$CLUSTER_CHANNEL"
+    xwiki_replace_example 'observation.remote.channels' "\$CLUSTER_CHANNEL"
   else
-    xwiki_set_properties 'observation.remote.channels' 'udp'
+    xwiki_replace_example 'observation.remote.channels' 'udp'
   fi
 }