If you are looking to deploy your critical web applications on a web server, nothing could be better than Apache Tomcat.

Tomcat is a lightweight and widely used web server based on the implementation of Java servlets, JSP, and Java expression language. Tomcat provides a pure Java HTTP web server environment where java code runs. Many applications are hosted on tomcat as this is open-source, a victory for system operators.

In this tutorial, you will learn how to install Apache Tomcat 10.0 on an Ubuntu Linux machine.

Table of Content

1. Prerequisites
2. How to Install Java 11 on ubuntu 18.04 machine
3. How to Install Tomcat 10 on ubuntu 18.04 machine
4. Tomcat files and Tomcat directories on a remote node
5. Conclusion

Prerequisites

This post will be a step-by-step tutorial. To follow along, be sure you have the following:

• An Ubuntu 14.04.4 LTS or greater Linux machine. This tutorial uses Ubuntu 18.04.5 LTS

Apache Tomcat is supported on all Windows, Linux, and macOS operating systems.

How to Install Java 11 on ubuntu 18.04 machine

As previously specified, Tomcat requires Java to be installed as tomcat implements Java-based technologies. If you don’t have java installed, let’s learn how to install Java Version 11 on the ubuntu 18.04 machine.

• Connect to Ubuntu machine using your favorite SSH client.
• Next, install java by running the apt install command. default-jdk is an open source java runtime which is most widely used.

# Installing Java Version: Java SE 11 (LTS)
sudo apt install default-jdk 

• After apt install default-jdk command is executed successfully , verify if java has been installed successfully by running the below command.

java -version               # To check the Installed Java Version

• To verify the Java you can also check the location of java binaries using which and whereis commands.

which java                  # Provides the location of executable file 
whereis java               # Provides location of all the files related to Java

• Run the below command to check the installation path of java. The system should respond with the path where Java is installed

update-alternatives --list java

If you have multiples Java installed on your machine and if you want to switch from one Java to another version consider running update-alternatives --config java command.

How to install Tomcat 10 on ubuntu 18.04 machine

Now that you have Java installed successfully installed on the ubuntu 18.04 machine, which is great. Next, you need to install a tomcat. Installing Tomcat is a straightforward task; let’s checkout.

• Create a folder named tomcat inside the opt directory mkdir command.

cd /opt
mkdir tomcat

• Download the Binary distribution of Tomcat 10 using curl command as shown below..

curl -O https://mirrors.estointernet.in/apache/tomcat/tomcat-10/v10.0.4/bin/apache-tomcat-10.0.4.tar.gz

• Extract the tomcat archieve that you just downloaded using tar command. After you execute the tar command you should see the tomcat folder in the opt directory.

 sudo tar xzvf apache-tomcat-10.0.4.tar.gz -C /opt/tomcat --strip-components=1

• Now that you have tomcat installed but you should consider running tomcat as a tomcat user which should be the part of tomcat group.
• Creating a new group tomcat using groupadd command.

sudo groupadd tomcat

• Next, create a tomcat user using useradd command and make it part of tomcat group .
  • -s /bin/false denotes that nobody can login as this user
  • /opt/tomcat will be tomcat home directory.

sudo useradd -s /bin/false -g tomcat -d /opt/tomcat tomcat      

• To run tomcat as tomcat user assign the tomcat user and tomcat group to the tomcat directory.

cd /opt/tomcat                     # Go to tomcat directory
sudo chgrp -R tomcat /opt/tomcat   # tomcat group given group ownership on /opt/tomcat
sudo chmod -R g+r conf             # Assign Read permission to tomcat group on conf
sudo chmod g+x conf                # Assign Execute permission to tomcat group on conf
sudo chown -R tomcat opt/tomcat    # Assign tomcat as owner of the directory 

• Now you are ready to start the tomcat application but it is always recommended to run the application using a service because the service saves applications to stop if the system reboots mistakenly or by any means. Let’s create the tomcat service.

• To create the tomcat service create a new file named tomcat.service as shown below.

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

• Next, copy and paste the below code in tomcat.service

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

[Service]
Type=forking

Environment=JAVA_HOME=/usr/lib/jvm/java-1.11.0-openjdk-amd64
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat

ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh

User=tomcat
Group=tomcat
UMask=0007
Restart=always

[Install]
WantedBy=multi-user.target

• Next, run the below commands to load the tomcat.service file & then start and enable the service.

sudo systemctl daemon-reload    # This will load the file in systemd and it.
sudo systemctl start tomcat     # Start the tomcat service
sudo systemctl enable tomcat    # Enable the tomcat service
sudo systemctl status tomcat    # Enable the tomcat service

By now, Apache Tomcat 10 service should be started and running successfully. To verify the tomcat application, navigate to the default webpage on the browser and type <IP-address-of your-tomcat-server>:8080.

Make sure to check your inbound rules and if port 8080 is open.

Tomcat files and Tomcat directories on a remote node

Now that you have successfully installed the tomcat on the remote node and verified the tomcat service, it is equally important to check the tomcat files created and the purpose of each of them.

• Firstly all the tomcat files and tomcat directories are stored under <tomcat-installation-directory>/*.

Your installation directory is represented by environmental variable  $CATALINA_HOME

• The tomcat directory and files should be owned by user tomcat
• The tomcat user should be member of tomcat group.

• <tomcat-installation-directory>/bin: This directory consists of startup and shutdown scripts (startup.sh and shutdown.sh) to run or stop the tomcat directly without using the tomcat service configured.

• <tomcat-installation-directory>/conf: This is very crucial directory where tomcat keeps all its configuration files.

• <tomcat-installation-directory>/logs: In case you get any errors while running your tomcat then you can look at your safeguard ie. logs , tomcat creates its own logs under this directory.

• <tomcat-installation-directory>/webapps: This is the directory where you place your code such as .war and run your applications. It is highly recommended to stop tomcat and then deploy your application inside this directory and then start tomcat.

Conclusion

In this tutorial, you have learned how to install Apache Tomcat on an Ubuntu server. Deploying Java applications on Apache Tomcat is a quick and easy process!

Apache Tomcat is the most widely used open-source tool for Java developers to run their web applications. Now that you have installed Apache Tomcat, which Java application will you deploy and manage next?