Tomcat on CentOS

Installation and Configuration on CentOS

Requirement

Open a terminal and switch to root user.

su -
yum install -y java-1.8.0 wget
java -version           

Create Tomcat Service Account

groupadd tomcat
useradd -g tomcat -d /opt/tomcat -s /bin/nologin tomcat           

Download & Setup Apache Tomcat

wget http://www-us.apache.org/dist/tomcat/tomcat-8/v8.5.20/bin/apache-tomcat-8.5.20.tar.gz
tar -zxvf apache-tomcat-*.tar.gz
mv apache-tomcat-8.5.20/* /opt/tomcat/
chown -R tomcat:tomcat /opt/tomcat/           

Set Environment Variables

mkdir /opt/tomcat/bin/setenv.sh
chmod 777 /opt/tomcat/bin/setenv.sh           

Example:

export variableName=value
...           

Systemd

vi /etc/systemd/system/tomcat.service           

Add below information to Tomcat systemd service file.

[Unit]
Description=Apache Tomcat 8.x Web Application Container
Wants=network.target
After=network.target

[Service]
Type=forking

Environment=JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.141-1.b16.el7_3.x86_64/jre
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment='CATALINA_OPTS=-Xms512M -Xmx1G -Djava.net.preferIPv4Stack=true'
Environment='JAVA_OPTS=-Djava.awt.headless=true'

ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh
SuccessExitStatus=143

User=tomcat
Group=tomcat
UMask=0007
RestartSec=10
Restart=always

[Install]
WantedBy=multi-user.target           

Reload systemd daemon.

systemctl daemon-reload
systemctl start tomcat
systemctl status tomcat
systemctl enable tomcat   //Enable the auto start of Tomcat service on system start           

Verify Apache Tomcat

By default, Tomcat runs on port no 8080. Use netstat command to check whether the service is listening on port 8080 or not.

netstat -antup | grep 8080           

Output:

tcp6       0      0 :::8080                 :::*                    LISTEN      2428/java           

Firewall

You may need to allow port 8080 in the firewall so that we can access Tomcat from external networks.

firewall-cmd --permanent --add-port=8080/tcp
firewall-cmd --reload