What is Jenkins?

Jenkins is a free, open-source automation server that enables continuous integration (CI) and continuous delivery (CD) of software. It automates tasks like building, testing, and deploying code, helping teams deliver applications reliably and efficiently.

Jenkins supports a plugin-rich architecture, integrates with virtually all major development, testing, and deployment tools, and is highly customizable through Jenkinsfiles and scripting.

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Why Use Jenkins on AlmaLinux 9?

AlmaLinux 9 is a community-driven, enterprise-ready alternative to CentOS, fully binary-compatible with Red Hat Enterprise Linux (RHEL) 9. It is a solid operating system choice for running Jenkins because of its stability, security, and long-term support.

Key advantages of using Jenkins on AlmaLinux 9:

• Enterprise-grade OS with 10-year support (until 2032)
• Full compatibility with Java 17+, required by current Jenkins versions
• Works with dnf, systemd, SELinux, and firewalld
• Supported by the official Jenkins YUM repository for easy setup and updates
• Ideal for use in production-grade CI/CD pipelines and automation environments

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Core Features of Jenkins

Feature	Description
CI/CD Pipelines	Automate build, test, and deployment workflows using code (Jenkinsfile)
Plugin Ecosystem	1,800+ plugins for version control, containers, notifications, and more
Web Interface	Browser-based UI for managing jobs, builds, and users
Pipeline as Code	Write declarative or scripted pipelines stored in version control
Integration Ready	Supports GitHub, GitLab, Docker, Ansible, Kubernetes, and more
Build Agents	Run distributed builds on remote workers or containers

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Common Use Cases

• Automating testing and deployment for applications
• Coordinating DevOps pipelines in multi-stage environments
• Managing container builds and Helm chart deployments
• Running infrastructure automation with tools like Terraform or Packer
• Performing static code analysis and security scanning
• Supporting microservices and monoliths alike

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System Integration on AlmaLinux 9

• Java Requirement: Jenkins requires Java 17+; installable via EPEL/Remi or Adoptium builds
• Service Management: Jenkins runs as a systemd service (jenkins.service)
• Web Access: Default port 8080; accessible via browser
• Configuration: Data stored in /var/lib/jenkins, with logs in /var/log/jenkins
• Firewall & Security: Easily managed using firewalld and SELinux enforcement

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Security Practices

To safely run Jenkins in production on AlmaLinux 9:

• Enable HTTPS using a reverse proxy (Nginx or Apache) and Let’s Encrypt
• Limit access to Jenkins ports with firewalld rules
• Integrate with LDAP, GitHub OAuth, or SAML for authentication
• Use role-based access control (RBAC) via Matrix Authorization Plugin
• Harden system with SELinux (configure correct file contexts for Jenkins directories)
• Disable anonymous access and rotate credentials regularly

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Performance Optimization Tips

• Use SSDs for fast I/O during builds
• Configure dedicated build agents for parallel or resource-intensive tasks
• Tune Java heap memory for large-scale jobs
• Archive logs and artifacts externally (S3, NAS, etc.) to save disk space
• Implement build throttling and pipeline optimization to reduce load

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Jenkins on AlmaLinux 9 provides a secure, stable, and scalable environment for automating software development pipelines. The combination of Jenkins’ extensive integration support and AlmaLinux’s enterprise-ready foundation makes it a dependable solution for modern DevOps teams.

Whether you’re deploying in a private cloud, hybrid infrastructure, or air-gapped environment, Jenkins on AlmaLinux 9 can support everything from basic CI to advanced release workflows.

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Step 1: Create a New AlmaLinux 9 Server on Shape.Host

To get started:

Go to https://shape.host and log in.

Click “Create”, then select “Instance”.

Choose your preferred server location.

Select AlmaLinux 9 (64-bit) as your OS.

Pick a plan with at least 2 CPUs, 4 GB RAM, and 20 GB SSD.

Click “Create Instance”.

Once it’s deployed, copy your instance’s IP address from the Resources section.

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Step 2: Connect to Your Instance

From Linux/macOS:

ssh root@your_server_ip

From Windows, use PuTTY.

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Step 3: Update System Packages

dnf update

This refreshes your system’s package list and installs available updates.

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Step 4: Install Java (Jenkins requirement)

dnf install java-17-openjdk

Jenkins needs Java to run. This command installs OpenJDK 17.

Check Java installation:

java -version

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Step 5: Add Jenkins Repository and Key

Import the official GPG key:

curl -fsSL https://pkg.jenkins.io/redhat-stable/jenkins.io-2023.key | tee /etc/pki/rpm-gpg/RPM-GPG-KEY-jenkins.io > /dev/null

Add the Jenkins repository configuration:

cat <<EOF > /etc/yum.repos.d/jenkins.repo
[jenkins]
name=Jenkins-stable
baseurl=https://pkg.jenkins.io/redhat-stable
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-jenkins.io
EOF

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Step 6: Install Jenkins

dnf install jenkins

This command installs the Jenkins service on your system.

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Step 7: Start and Enable Jenkins

systemctl enable --now jenkins

This starts Jenkins immediately and enables it to start on boot.

Check if Jenkins is running:

systemctl status jenkins

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Step 8: Set Up Firewall with UFW

Install UFW (Uncomplicated Firewall):

dnf install ufw

Enable and start UFW:

systemctl enable --now ufw

Allow SSH access:

ufw allow 22/tcp

Allow Jenkins port:

ufw allow 8080/tcp

Check firewall status:

ufw status

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Step 9: Get Jenkins Admin Password

To access the Jenkins dashboard, you’ll need the initial admin password:

cat /var/lib/jenkins/secrets/initialAdminPassword

Copy this password to use in the next step.

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Step 10: Access Jenkins Web Interface

Open your browser and go to:

http://your-server-ip:8080

Paste the password when prompted, then complete the setup wizard.

Click “Install suggested plugins”

Create your admin user

Confirm Jenkins URL

Click “Start using Jenkins”

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• Clean AlmaLinux Cloud VPS for CI/CD
• Instant server provisioning
• Root access and full control
• Global data center options

Get started at https://shape.host and launch your Jenkins environment in minutes.