This post details some issues encountered when installing Tomcat web server from package onto Ubuntu 16.04.

When running the standard sudo apt-get install tomcat7 command, Tomcat is downloaded and unpackaged however it fails to complete the install and produces this error:

Setting up tomcat7 (7.0.26-1ubuntu1.1) ...  
chmod: cannot access `/etc/tomcat7/tomcat-users.xml': No such file or directory  
dpkg: error processing tomcat7 (--configure):  
 subprocess installed post-installation script returned error exit status 1  
No apport report written because MaxReports is reached already  
                                                             
 >Errors were encountered while processing:  
 tomcat7  
E: Sub-process /usr/bin/dpkg returned an error code (1)

This is caused by improper permissions group assignment of the Tomcat config file. To resolve this I simply removed the file sudo rm /etc/tomcat7/tomcat-users.xml and then re-ran the installation again.

I thought I was out of the woods but then after re-installing I got a new error with exit status 1. After checking the journalctl I discovered that Tomcat could not find the default locations for Java and was searching for OpenJava other locations.
Which was strange because JAVA_HOME was set on my environment but not in my bash config. The solution as was identified on StackOverflow is the following.

gksudo gedit /etc/default/tomcat7

Inside the editor look for the commented out line for JAVA_HOME, then specify it to your Oracle Java location which is normally /usr/lib/jvm/java-8-oracle.

After saving this change and restarting Tomcat, you should be cooking with gas!