java web application deployment through CI/CD using tomcat

Launch t2.large instance on AWS

Install Tomcat

Donload tomcat from https://tomcat.apache.org/download-90.cgi

Right click on tar.gz and copy link address, download packge on ubuntu with wget

wget https://dlcdn.apache.org/tomcat/tomcat-9/v9.0.102/bin/apache-tomcat-9.0.102.tar.gz

Create a directory under /opt to extract files

sudo mkdir -p /opt/tomcat

Extract the downloaded Tomcat Tar file into the created directory.

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

Create a dedicated user

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

Create a Systemd service file for tomcat service

Create Systemd unit file for tomcat service

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

Paste the following block of code in it

[Unit]
Description=Tomcat webs servlet container
After=network.target

[Service]
Type=forking

User=tomcat
Group=tomcat
RestartSec=10
Restart=always 
Environment="JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64"
Environment="JAVA_OPTS=-Djava.awt.headless=true -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

To save the press Ctrl+X, type Y, and hit the Enter Key.

Start enable tomcat

sudo systemctl daemon-reload
sudo systemctl start tomcat
sudo systemctl enable tomcat

To confirm everything is working normally, check the status of service:

sudo systemctl status tomcat

Add Roles and Admin username and password

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

<role rolename="admin-gui,manager-gui,manager-script,manager-jmx,manager-status,admin-gui"/>
<user username="admin" password="password" roles="admin-gui,manager-gui,manager-script"/>

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

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

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

comment Vlave as above

Restart Tomcat service:

sudo systemctl restart tomcat

Access tomcat

http://server-ip-addres:9090
or 
http://youdomain.com:9090

Install jenkins

sudo apt update
sudo apt install fontconfig openjdk-17-jre -y
sudo wget -O /usr/share/keyrings/jenkins-keyring.asc \
  https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key
echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc]" \
  https://pkg.jenkins.io/debian-stable binary/ | sudo tee \
  /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt-get update
sudo apt-get install jenkins -y
sudo systemctl start jenkins
sudo systemctl enable jenkins

<EC2 Public IP Address:8080>
sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Create user for jenkins and login

In Jenkins UI, Install bellow plugins

Click on generate pipline script

deploy adapters: [tomcat9(credentialsId: 'tomcat', path: '', url: 'http://54.226.203.188:9090/')], contextPath: null, war: '**/*.war'

pipeline {
    agent any

    tools {
        maven 'Maven3'
    }

    stages {
        stage('Clean Workspace') {
            steps {
                cleanWs()
            }
        }

        stage('1. Clone the Project') {
            steps {
                git branch: 'master', url: 'https://github.com/abcd/abcd.git'
            }
        }

        stage('2. Compile') {
            steps {
                sh 'mvn compile'
            }
        }

        stage('3. Test') {
            steps {
                sh 'mvn test'
            }
        }

        stage('4. Package') {
            steps {
                sh 'mvn package'
            }
        }

        stage('5. Deploy to Container') {
            steps {
                echo "Deploying code..."
                deploy adapters: [
                    tomcat9(
                        credentialsId: 'tomcat',
                        path: '',
                        url: 'http://65.2.124.188:9090/'
                    )
                ], contextPath: null, war: '**/*.war'
            }
        }
    }
}

instance-ip:9090/your-war-file