Installation of Tomcat 10 on Ubuntu

1. Install Java

Upgrade the system

$ sudo apt upgrade

Update system packages.

$ sudo apt update

Install Java runtime environment.

$ sudo apt install default-jdk -y

Verify Java installation.

$ java -version

How to find the OpenJDK directory with the following command:

$ readlink -f /usr/bin/javac

As you can have multiple versions of Java installed on your system, you can decide which one is the default one.First, run a command that shows all the installed versions on your computer:

$ sudo update-alternatives --config java

2. Install Tomcat

Download the latest version of Apache Tomcat. To find the latest Tomcat version, visit the official download page.

$ wget https://dlcdn.apache.org/tomcat/tomcat-10/v10.0.23/bin/apache-tomcat-10.0.23.tar.gz

Extract the downloaded archive.

$ sudo tar xzvf apache-tomcat-10.0.23.tar.gz

Create an installation directory /opt/tomcat/.

$ sudo mkdir /opt/tomcat/

Move the extracted files to the installation directory.

$ sudo mv apache-tomcat-10.0.23/* /opt/tomcat/

Since you have already created a user, you can now grant tomcat ownership over the extracted installation by running:

sudo chown -R tomcat:tomcat /opt/tomcat/
sudo chmod -R u+x /opt/tomcat/bin
Edit conf/tomcat-users.xml file to configure an administrator and manager 

account for Apache Tomcat.

$ sudo nano /opt/tomcat/conf/tomcat-users.xml

Add the code below within the <tomcat-users> tag. Change the password for administrator and manager access by changing the value StrongPassword below with a high secure password.

<!-- user manager can access only manager section -->
<role rolename="manager-gui" />
<user username="manager" password="manager" roles="manager-gui" />

<!-- user admin can access manager and admin section both -->
<role rolename="admin-gui" />
<user username="admin" password="admin" roles="manager-gui,admin-gui" />

Enable remote access to Apache Tomcat by editing manager and host-manager configuration files. Edit manager application context.xml file:

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

Comment out the IP addresses section as shown below. Then, save and close the file.

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

Edit host manager application context.xml file:

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

Comment out the IP addresses section as shown below. Then, save and close the file.

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

Create a systemd unit file for Apache Tomcat.

$ sudo nano /etc/systemd/system/tomcat.service

Add the code below to the file. Then, save and close the file.

[Unit]
Description=Tomcat
After=network.target

[Service]
Type=forking

User=root
Group=root

Environment=JAVA_HOME=/usr/lib/jvm/java-1.11.0-openjdk-amd64
Environment=JAVA_OPTS=-Djava.security.egd=file:///dev/urandom
Environment=CATALINA_BASE=/opt/tomcat
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC

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

[Install]
WantedBy=multi-user.target

Reload the system daemon service to apply changes.

$ sudo systemctl daemon-reload

Start Apache Tomcat service.

$ sudo systemctl start tomcat

Enable the service to start up on system boot.

$ sudo systemctl enable tomcat

Check the status of the service.

$ sudo systemctl status tomcat 

Note: press ctrl +c after running the above coomand 

Note:Bydefault localhost:8080 if it does not start then we need 

to change the localhost:8081 and repeat the above 4 commands 

i.e reload start,enable,check

root@ubuntu:/opt/tomcat# cd conf/
root@ubuntu:/opt/tomcat/conf# ls
Catalina             context.xml           logging.properties  tomcat-users.xsd
catalina.policy      jaspic-providers.xml  server.xml          web.xml
catalina.properties  jaspic-providers.xsd  tomcat-users.xml
root@ubuntu:/opt/tomcat/conf# gedit server.xml 

3. Access Apache Tomcat Web Interface

Go to your browser address bar to access the web interface and type in http://ServerIPaddress:8080 for SuiteCRM to access the web install wizard. For example:

localhost:8081/

Note:If still it is not working then we need to use the following coomands

root@ubuntu:/opt/tomcat/bin# ./shutdown.sh 
root@ubuntu:/opt/tomcat/bin# ./startup.sh