Ref 1
Ref 2
Ref 3

Goal

I'd like to be able to use the upstream/downloaded Tomcat, running as a standalone, serving 80/443 ports, and starting automatically with system boot.
Below is based on vanilla Ubuntu 16.04 image from Google Compute Engine.

How

Install Java

sudo apt install default-jdk-headless

Add tomcat user and group

With --system so that this user could not sign in system.

sudo addgroup --system tomcat
sudo adduser --system --ingroup tomcat tomcat

Unpack Tomcat installation

Download apache-tomcat-8.0.35.tar.gz. Then:

tar xf apache-tomcat-8.0.35.tar.gz
sudo mv apache-tomcat-8.0.35 /home/tomcat/
sudo chown tomcat:tomcat -R /home/tomcat/apache-tomcat-8.0.35

Install and configure authbind

sudo apt install authbind
sudo touch /etc/authbind/byport/{443,80}
sudo chmod 500 /etc/authbind/byport/{443,80}
sudo chown tomcat:tomcat /etc/authbind/byport/{443,80}

Configure Tomcat

sudo sed -i 's/8080/80/g' /home/tomcat/apache-tomcat-8.0.35/conf/server.xml
sudo sed -i 's/8443/443/g' /home/tomcat/apache-tomcat-8.0.35/conf/server.xml

Configure authbind

sudo vim /etc/systemd/system/tomcat.service

Then paste in the content:


[Unit]
Description=Tomcat Container
After=network.target

[Service]
Type=forking

Environment=JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/jre
Environment=CATALINA_PID=/home/tomcat/tmp/tomcat.pid
Environment=CATALINA_HOME=/home/tomcat/apache-tomcat-8.0.35
Environment=CATALINA_BASE=/home/tomcat/apache-tomcat-8.0.35

ExecStart=/home/tomcat/apache-tomcat-8.0.35/bin/startup.sh
ExecStop=/home/tomcat/apache-tomcat-8.0.35/bin/shutdown.sh

User=tomcat
Group=tomcat
RestartSec=10
Restart=always

[Install]
WantedBy=multi-user.target

After saving: