Apache Tomcat

Java and its multipurpose language and that make it so good and useful to learn. Well, after coding your web application, it gets to the point where you have to deploy it. To do this, it requires a server that can interpret that Java code. Remember that we are talking about web applications. And to deploy and serve it, nothing like Apache Tomcat.

Estricatemente speaking Tomcat is not a server but transforms the caught JPS into servlets that can serve the application in question.

On the other hand, Apache Tomcat is open source and can be installed on any system running Java.

Install Apache Tomcat on Ubuntu 20.04 / Debian 10

1) Install and configure Java on Ubuntu 20.04 / Debian 10

Apache Tomcat is an application made with Java. Therefore, the first step is to install Java on Debian 10.

Open a terminal session and run the following:

:~$ sudo apt install default-jre default-jdk

Then, check the java version.

:~$ java --version
openjdk 11.0.3 2019-04-16
OpenJDK Runtime Environment (build 11.0.3+7-post-Debian-5)
OpenJDK 64-Bit Server VM (build 11.0.3+7-post-Debian-5, mixed mode, sharing)

As you can see, Java version 11 has been installed. It is one of the most recent and with very good support.

Now, you have to modify the /etc/environment file and add the Java path.

:~$ sudo nano /etc/environment

And add the following:

JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64/"

Save the changes and close the file.

The next step is to edit the .bashrc file and add the following:

:~$ sudo nano .bashrc

export JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64/"
export PATH=$JAVA_HOME/bin:$PATH

Again, save the changes and close the file.

Next, refresh the bash.

:~$ source .bashrc

Now, type this command to test the Java path.

:~$ echo $JAVA_HOME
/usr/lib/jvm/java-11-openjdk-amd64/bin/java

So, if you got the Java path from your computer, everything is correct.

2) Install Apache Tomcat on Ubunut 20.04 / Debian 10

For security reasons, it is convenient to create a new user for Tomcat. Also, add it to a group called tomcat.

:~$ sudo -i
:~# groupadd tomcat
:~# useradd -s /bin/false -g tomcat -d /opt/tomcat tomcat

Now we can install Apache Tomcat. To do this, go to the /opt/ folder and download with wget.

:~# cd /opt/
:~# wget -c https://downloads.apache.org/tomcat/tomcat-9/v9.0.39/bin/apache-tomcat-9.0.39.tar.gz
--2020-10-28 19:23:24-- https://downloads.apache.org/tomcat/tomcat-9/v9.0.39/bin/apache-tomcat-9.0.39.tar.gz
Resolving downloads.apache.org (downloads.apache.org)... 88.99.95.219, 2a01:4f8:10a:201a::2
Connecting to downloads.apache.org (downloads.apache.org)|88.99.95.219|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 11282879 (11M) [application/x-gzip]
Saving to: ‘apache-tomcat-9.0.39.tar.gz’
apache-tomcat-9.0.39.tar.gz 100%[=====================================================================================>] 10.76M 157KB/s in 1m 49s
2020-10-28 19:25:15 (101 KB/s) - ‘apache-tomcat-9.0.39.tar.gz’ saved [11282879/11282879]

Then, decompress it and rename the folder.

:~# tar -xzvf apache-tomcat-9.0.39.tar.gz
:~# mv apache-tomcat-9.0.39 tomcat

After that, you need to change the owner of the folder and assign the required permissions so that it can run smoothly. Remember that now, we are using the root user.

:~# chown -R tomcat:tomcat /opt/tomcat/
:~# chmod +x /opt/tomcat/bin/*

Now, on the .bashrc file add the CATALINA_HOME path.

:~# nano ~/.bashrc
export CATALINA_HOME=/opt/tomcat

Save the changes and close the file.

Then, refresh bash.

:~# source ~/.bashrc

After that, we can run Apache Tomcat. To do it, just type this command:

:~# /opt/tomcat/bin/startup.sh

Next, open your web browser ad go http://your-server:8080. And you will see this.

If you want to set a password to improve security of the manager web app. So, open the tomcat-users.xml

:~# nano /opt/tomcat/conf/tomcat-users.xml

In the tomcat-user section, you have to add the username and password.

<role rolename="manager-gui"/>
<user username="XXXXXX" password="XXXXXXX" roles="manager-gui,admin-gui"/>

Of course, replace the password for yours.

Then, restart Tomcat.

:~# ./shutdown.sh
:~# ./startup.sh

And go to the web browser again. Next, refresh the page. And that is it.

Conclusion

Apache Tomcat is the best solution to deploy and serve web applications made with Java. So if you program in Java, you should learn how to manipulate Tomcat. As you have learned in this post, it is not very complex to learn how to install it in  Ubuntu 20.04 / Debian 10.

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The post How to install Apache Tomcat on Ubuntu 20.04 / Debian 10? appeared first on Linux Windows and android Tutorials.

In short, Apache Tomcat executes Java servlets and renders Web pages that include Java Server Page coding. It constitutes a base element for the development with Java. It is very popular and it is open source.

This time I will install using CentOS 7, which is a Red Hat-based Linux distribution for use on Servers.

What you need

The process is very simple and you should not take long to do it, but it is good that you know that there are some small requirements to successfully complete this tutorial.

• A server with CentOS 7 installed and allowing access via ssh.
• A basic knowledge about the use of commands in the terminal.
• A user who allows commands to be run as root. Or root access.

I think this will be enough for you to do everything without problems.

Let’s get to work.

1. Upgrade the system

In order to have the latest security patches, it is necessary to update the system completely. Also with this, you will have a more secure server and in many cases faster. Run as root user:

:~# yum update

That’s enough.

2.- Install Java

To install Apache Tomcat you first need to install Java because it is a dependency. To do this, type the following:

:~# yum install java-1.8.0-openjdk.x86_64 java-1.8.0-openjdk-devel.x86_64

Next, check the installed Java version.

:~# java -version

As you can see, Java was correctly installed. This was done because Apache Tomcat 9 requires at least Java 8.

3. Install Apache Tomcat 9

Go to the official Apache Tomcat site and download the latest stable version.

Of course, you are working on a server, the best is to get the link directly and run:

:~# cd /opt/
:~# wget http://ftp.wayne.edu/apache/tomcat/tomcat-9/v9.0.12/bin/apache-tomcat-9.0.12.zip

Now proceed to decompress it.

:~# unzip apache-tomcat-9.0.12.zip

Then, rename the decompressed file to a simpler one.

:~# mv apache-tomcat-9.0.12 tomcat

Next, you have to set the CATALINA_HOME environment variable.

:~# echo "export CATALINA_HOME='/opt/tomcat/'" >> ~/.bashrc
:~# source ~/.bashrc

If you are going to install Apache Tomcat on a public server, then it is preferable to create a new system user to run it.

:~# useradd -r tomcat --shell /bin/false

Then, it changes the ownership of the folder to that of the new user. I named it to tomcat.

:~# chown -R tomcat:tomcat /opt/tomcat/

4. Making Apache Tomcat as a service

To properly handle Apache Tomcat, it is a good idea to create a file that is made by a system service. This way you can start it, restart it or stop it in a simpler way. Run:

:~# nano /etc/systemd/system/tomcat.service

And put the following:

[Unit]
Description=Apache Tomcat 9
After=syslog.target network.target

[Service]
User=tomcat
Group=tomcat
Type=forking
Environment=CATALINA_PID=/opt/tomcat/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh
Restart=on-failure

[Install]
WantedBy=multi-user.target

Save and close the file. Now run:

:~# systemctl daemon-reload

5. Create an Apache Tomcat user account

To access Tomcat Manager, you have to create a new user. The process is simple, you have to edit the file /opt/tomcat/conf/tomcat-users.xml.

:~# nano /opt/tomcat/conf/tomcat-users.xml

And add the following:

<role rolename="admin-gui"/>
<user username="admin" password="PASSWORD" roles="manager-gui,admin-gui"/>
</tomcat-users>

Remember to change “PASSWORD” for your real password.

6. Starting the service and accessing through a web browser

Now you can start the Apache Tomcat service. Then check its status and finally access it from the web browser.

Now, you can start Apache Tomcat either using systemctl or from its own script.

:~# sh /opt/tomcat/bin/startup.sh

Now go to http://IP_SERVER/manage/html and log in with your username and your password.

Conclusion

Apache Tomcat is a vital tool for Java development and its installation is really simple on Linux and CentOS 7.

Let us know about you, Java programs? what is your experience with Tomcat? Did you find the tutorial easy?

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