Tutorial Install Apache Tomcat 8 on CentOS 7

Apache Tomcat is an open-source implementation of the Java Servlet and JavaServer Pages technologies. It is a web server which is released by the Apache Software Foundation. But before swimming into the sea of this guide, make sure you have your own Linux Virtual Private Server.

To let this tutorial work better, please consider the below Prerequisites:

A non-root user with sudo privileges

Tutorial Install Apache Tomcat 8 on CentOS 7

Let’s walk through the steps of this tutorial to see how to Install Apache Tomcat 8 on CentOS 7 and also its configuration.

Step 1: How To Install Java

The pre-step of installing Tomcat is to install Java on the server. Feel free to choose any Java web application code. So use the following command with yum to install OpenJDK.

sudo yum install java-1.7.0-openjdk-devel

When you are prompted, press y to continue installing OpenJDK 7.

While you have installed Java, you are ready to create a tomcat user to let it run the Tomcat service.

Note: You can find a shortcut to the JAVA_HOME directory at /usr/lib/jvm/jre and remember to use it to configure Tomcat later.

Step 2: How To Create Tomcat User

In this step, you will watch for security. To reach this goal, you may have to run as an unprivileged user. So let’s create a new user and group to run the Tomcat service.

Use the command below to create a new tomcat group:

sudo groupadd tomcat

From now on you should ride as well as you do not let anyone log into the account. To do this, you need to create a new tomcat user. After that you would make this user a member of the tomcat group, with a home directory of /opt/tomcat and with a shell of /bin/false

sudo useradd -M -s /bin/nologin -g tomcat -d /opt/tomcat tomcat

Step 3: How To Install Tomcat

What if you learn the easiest way to install Tomcat 8? Yes, it is possible. You just need to download the latest binary release then configure it manually.

How To Download Tomcat Binary

Use the shortest way of downloading the latest version of Tomcat 8 and visit Tomcat 8 Downloads page. Once you have it, under the Core list, copy the link to the “tar.gz”.

Now, using the yum package manager start to install wget.

sudo yum install wget

And, if you want to change to your home directory:

cd ~

Next, to download the Tomcat 8 archive, use wget and paste in the link.

wget https://www-eu.apache.org/dist/tomcat/tomcat-8/v8.5.37/bin/apache-tomcat-8.5.37.tar.gz    

At this point, it is time to install Tomcat to the /opt/tomcat directory. To do this better extract the archive to the directory with the below commands.

sudo mkdir /opt/tomcat  sudo tar xvf apache-tomcat-8*tar.gz -C /opt/tomcat --strip-components=1

How To Update Permissions

It is necessary to assign access to the Tomcat installation for the tomcat user. Run the following command to change to the Tomcat installation path:

cd /opt/tomcat

Then, try to give the tomcat group ownership over the entire installation directory:

sudo chgrp -R tomcat /opt/tomcat

Now, you can assign the tomcat group read access to the conf directory with all its content. After that type the command below to execute access, to the directory itself:

sudo chmod -R g+r conf  sudo chmod g+x conf    

As you guess, the tomcat user should be the owner of the webapps, work, temp, and logs directories now.

sudo chown -R tomcat webapps/ work/ temp/ logs/

How To Install Systemd Unit File

To set up this section, you need to run a Tomcat Systemd unit file to let you set up Tomcat as a service.

Type the following command to create and open the unit file:

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

In case you need to modify the memory allocation settings that are specified in CATALINA_OPTS. And paste in the following script.

# Systemd unit file for tomcat  [Unit]  Description=Apache Tomcat Web Application Container  After=syslog.target network.target    [Service]  Type=forking    Environment=JAVA_HOME=/usr/lib/jvm/jre  Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid  Environment=CATALINA_HOME=/opt/tomcat  Environment=CATALINA_BASE=/opt/tomcat  Environment='CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC'  Environment='JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom'    ExecStart=/opt/tomcat/bin/startup.sh  ExecStop=/bin/kill -15 $MAINPID    User=tomcat  Group=tomcat  UMask=0007  RestartSec=10  Restart=always    [Install]  WantedBy=multi-user.target

Now you can save and exit. As you see, the script tells the server to run the Tomcat service as the tomcat user, with the settings specified.

After all, you can reload Systemd to load the Tomcat unit file:

sudo systemctl daemon-reload

To start the Tomcat service:

sudo systemctl start tomcat

You can use the command below to check if the service started successfully or not.

sudo systemctl status tomcat

If yes, it starts on server boot and you can enable the Tomcat service by running the following command:

sudo systemctl enable tomcat

As you see, you have not set up the Tomcat completely till here. So let’s access the default splash page by going to your domain or IP address followed by 8080 in a web browser:

http://server_IP_address:8080

Step 4: How To Configure Tomcat Web Management Interface

Anytime you decide to use the manager web app that comes with Tomcat, try to add a login to our Tomcat server. To start doing this, edit the  tomcat-users.xml file:

sudo vi /opt/tomcat/conf/tomcat-users.xml

You see so many comments which describe how to configure the file. So, you have two choices, first to delete all the comments between the following two lines, and second to leave them if you want to reference the examples:

<tomcat-users>  ...  </tomcat-users>

In order to add a user who can access the manager-gui and admin-gui let’s define a user similar to the example below. Do not forget to change the username and password to something secure:

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

You can now save and exit the tomcat-users.xml file.

If you work with the latest version of Tomcat, you will face that it restrict access to the Manager and Host Manager apps to connections coming from the server itself. Installing on a remote machine, you may prefer to remove or alter this restriction. Therefore, open the appropriate context.xml files, to change the IP address restrictions on these.

Run the command below for the Manager app:

sudo vi /opt/tomcat/webapps/manager/META-INF/context.xml

And type the following command for the Host Manager app, type:

sudo vi /opt/tomcat/webapps/host-manager/META-INF/context.xml

Inside, comment out the IP address restriction to allow connections from anywhere. Also, you can add your public IP address to the list, if you prefer to allow access only to connections coming from your own IP address.

<Context antiResourceLocking="false" privileged="true" >    <!--<Valve className="org.apache.catalina.valves.RemoteAddrValve"           allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />-->  </Context>

Now you can save and close the file when you finished.

Also you can restart the Tomcat service to put your changes into effect.

sudo systemctl restart tomcat

Step 5 : How To Access the Web Interface

Till now, Tomcat is up and running, so why you do not access the web management interface in a web browser?

Do this by accessing the public IP address of the server, on port 8080:

http://server_IP_address:8080

Then, you will see a page as below.

Have a look at the links to the admin web apps, which you configured an admin user for. Now, if you attend to the Manager App, it is accessible via the link or http://server_IP_address:8080/manager/html:

You would use the Web Application Manager to manage your Java applications. For some activities as Start, Stop, Reload, Deploy, and Undeploy. Or to run some diagnostics on your apps. Consider that you can access your information about your server, by the very bottom of this page.

However, let’s take a look at the Host Manager, accessible via the link or http://server_IP_address:8080/host-manager/html/:

The way you can use this page is to add virtual hosts to serve your applications.

conclusion

In this article, after passing the steps of this guide, you have successfully installed the Apache Tomcat 8 and you are ready to use it. Also, to see more related articles, read more on How to install Apache Tomcat on Windows.