As discussed in the introduction to this section, Red Hat does not offer Tomcat 8.5 on RHEL 7, so it must be downloaded and installed manually. Run the commands

casdev-master# mkdir -p /opt/tomcat
casdev-master# cd /opt/tomcat
casdev-master# curl -LO 'http://apache.cs.utah.edu/tomcat/tomcat-8/v8.5.27/bin/apache-tomcat-8.5.27.tar.gz'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 9313k  100 9313k    0     0  4036k      0  0:00:02  0:00:02 --:--:-- 4038k
casdev-master# tar xzf apache-tomcat-8.5.27.tar.gz
casdev-master# ln -s apache-tomcat-8.5.27 latest
casdev-master# rm -f apache-tomcat-8.5.27.tar.gz

to download and install Tomcat on the master build server (casdev-master). (Replace 8.5.27 in the commands above with the current stable version of Tomcat 8.5.) This will install the current version of Tomcat 8.5 in a version-specific subdirectory of /opt/tomcat, and make it accessible by the path /opt/tomcat/latest. By making everything outside this directory refer to /opt/tomcat/latest, an updated version can be installed and the link changed without having to edit/recompile anything else.