Using Apache Tomcat Server

This page is targeted at Scala Developers, who want to get a / some simple web applications going, or create a dynamic web site using Scala. However nearly everything will also apply to people who want to use Java, Kotlin and other JVM language. Its not geared towards advanced professional Scala developers who will almost all be using other solutions. If like me you come to the Tomcat Server, with only the experience of running Apache vanilla servers, setting up Tomcat is significantly more complicated than the extreme simplicity of installing an Apache Vanilla server. Note referring to it as Apache Vanilla is my own naming scheme as referring to it just as "Apache" can be confusing. So here follows a list of steps for setting up Tomcat on your own Desktop, laptop, home server or VPS.

1. Lease a VPS. A virtual private server. The price of these have dropped considerably over the years and will almost certainly continue to drop. You can purchase a VPS with a couple of cores and 4 Gig of RAM for a few dollars / pounds / Euros a month these days. If you are really tight with money you could probably get away with 2 gigs, but I would recommend starting with a comfortable 4 gigs. When starting out I recommend just buying monthly, as your needs will change. For the time being I don't have enough experience to make recommendations. I've had good service from Digital Ocean for a number of years running a VPS for Apache Vanilla, but they are some what pricey to get 4 gigs of ram for a small project with minimal users. I intend to come back and update this later. I'm currently using an Ubuntu Operating System, just out of familiarity. Now obviously if you are using your own desktop, laptop or home server, you won't need this step and you will probably want to try that first before spending money on a VPS. But you will almost certainly need one to get your site / app out to the world.
2. Install Java. Currently suggesting Java 21 LTS. Note the jdk at the end of the version. sudo apt install openjdk-21-jdk -y Check the version java -version openjdk version "21.0.8" 2025-07-15 OpenJDK Runtime Environment (build 21.0.8+9-Ubuntu-0ubuntu124.04.1) OpenJDK 64-Bit Server VM (build 21.0.8+9-Ubuntu-0ubuntu124.04.1, mixed mode, sharing)

3. There are default values here that you can change as you work down the page. Although once you've used a value, stick with it or you will create an inconsistent system. Insert your own values below. the data is used for page generation locally and is not sent back to our servers. User Name Computer Name System Ram Tomcat Version

   Create a new user and a new group of the same name and add it to the sudo group. For these examples we'll call it 'tommy'. I find it better to have a different name for the user than the folder we will create next. Again for desktop, laptop and home server this is not necessary and you can use your own username. sudo useradd -ms /bin/bash tommy sudo passwd tommy sudo useradd tommy sudo
4. Create a directory for tomcat and change the owner and group. The directory doesn't have to be called tomcat and placed in the Opt directory, but this is a pretty standard schema. You can use your own username on a home machine. sudo mkdir /opt/tomcat sudo chown tommy:tommy /opt/tomcat Switch user to tommy. Then change directory. sudo su tommy cd /opt/tomcat Create a directory called Base inside the tomcat directory. This will be used for CatalinaBase and will allow you to keep configuration files to use with multiple installs and major version changes of Apache. tommy@computer:/opt/tomcat mkdir Base
5. Go to the Apache Download page: https://tomcat.apache.org/download-11.cgi . Currently we're on major version 11. Generally you should use the latest version. I haven't tested these instructions before 10.0, but they should work at least back to version 9, if you have some specific reason to use an earlier version. At the time of writing I'm using the latest sub version 11.0.12. Copy the tar.gz file link into the browser. Once its downloaded copy the sha256 code into the next command to check the integrity of the download. If its good the sha code should be echoed back in red and the file name in white. tommy@computer:/opt/tomcat wget https://dlcdn.apache.org/tomcat/tomcat-11/v11.0.12/bin/apache-tomcat-11.0.12.tar.gz tommy@computer:/opt/tomcat sha512sum apache-tomcat-11.0.12.tar.gz | grep alongsequenceoflettersanddigits
6. Then unpack the tar file and create a link. This will allow us to easily swap in an updated minor version of Tomcat 11.0. These are released frequently. tommy@computer:/opt/tomcat tar xf apache-tomcat-11.0.12.tar.gz -C /opt/tomcat tommy@computer:/opt/tomcat ln -s apache-tomcat-11.0.12 tom11 Then checking what we've got. tommy@computer:/opt/tomcat ls apache-tomcat-11.0.12 apache-tomcat-11.0.12.tar.gz Base tom11
7. Create the logs and conf directories and copy across the server.xml and web.xml files from the installation directory structure to the base directory structure. If the catalina base and catalina home directories are the same, which is often the case in beginners installation instructions, then this is redundant. tommy@computer:/opt/tomcat mkdir Base/logs tommy@computer:/opt/tomcat mkdir Base/conf tommy@computer:/opt/tomcat cp tom11/conf/server.xml tom11/conf/web.xml Base/conf Create a home page for your server. Again not necessary if base and home are set to the same directory. tommy@computer:/opt/tomcat mkdir -p Base/webapps/ROOT tommy@computer:/opt/tomcat nano Base/webapps/ROOT/index.html Copy the code below into the editor.

   <!doctype html>
   <html>
   <head>
     <title>Holding Page</title>
   <meta charset='UTF-8'>
   <meta name='viewport' content='width=device-width,initial-scale=1.0'>
   </head>
   
   <body>
   <h1>Holding Page</h1>
   This is coming from a tomcat 11.0.12 server
   </body>
   </html>

8. Create a systemd unit file. sudo nano /etc/systemd/system/tom11.service [Unit] Description=Apache Tomcat 11.0 Web Application Container After=network.target
[Service] Type=forking
Environment="JAVA_HOME=/usr/lib/jvm/java-1.21.0-openjdk-amd64" Environment="CATALINA_PID=/opt/tomcat/Base/temp/tomcat.pid" Environment="CATALINA_HOME=/opt/tomcat/tom11/" Environment="CATALINA_BASE=/opt/tomcat/Base/" Environment="CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC" Environment="JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom" ExecStart=/opt/tomcat/tom11/bin/startup.sh ExecStop=/opt/tomcat/tom11/bin/shutdown.sh User=tommy Group=tommy UMask=0007 RestartSec=10 Restart=always [Install] WantedBy=multi-user.target
9. sudo systemctl daemon-reload sudo systemctl start tom11 sudo systemctl status tom11 If status good, open a web page at localhost:8080 sudo sytemctl enable tom11
10. To switch to port 80 sudo apt install authbind sudo touch /etc/authbind/byport/80 sudo chown tommy: /etc/authbind/byport/80 sudo chmod 500 /etc/authbind/byport/80 sudo nano /etc/systemd/system/tom11.service change --> ExecStart=/opt/tomcat/tom11/bin/startup.sh to --> ExecStart=authbind --deep /opt/tomcat/tom11/bin/startup.sh sudo nano /opt/tomcat/Base/conf/server.xml change <Connector port="8080" protocol to <Connector port="80" protocol sudo systemctl daemon-reload sudo systemctl restart tom11