It is NOT recommended to place elements directly in the server.xml file. So add a file called ROOT.xml in /conf/Catalina/localhost/ folder

This ROOT.xml will override the default settings for the root context of the tomcat installation for that engine and host (Catalina and localhost).

Rename your application which you need to deploy in the tomcat document root as ROOT.war and it will create a ROOT folder when it get deployed in webapps folder.

Enter the following to the ROOT.xml file;