Architecture

CI/CD & Jenkins Architecture

🔹 CI/CD Architecture Overview

CI/CD (Continuous Integration and Continuous Deployment) automates software development workflows, ensuring faster and more reliable releases.

1️⃣ CI/CD Workflow:

1. Developer Pushes Code → Commits changes to GitHub/GitLab/Bitbucket

2. CI/CD Pipeline Triggers → Jenkins/GitHub Actions detects changes

3. Code is Built → Uses tools like Maven, Gradle, Docker

4. Automated Testing → Unit, Integration, Security tests

5. Artifact Storage → Deployable files stored in JFrog, Nexus, AWS S3

6. Deployment → CI/CD deploys to Kubernetes, AWS, or on-prem servers

7. Monitoring & Feedback → Prometheus/Grafana alerts for failures

2️⃣ CI/CD Pipeline Stages

• Source Stage → Fetch code from Git

• Build Stage → Compile and package

• Test Stage → Run automated tests

• Deploy Stage → Push to production

---

🔹 Jenkins Architecture

Jenkins follows a Master-Agent (Controller-Worker) Architecture to distribute workloads efficiently.

1️⃣ Jenkins Master (Controller)

• Manages build processes and configurations

• Schedules jobs, triggers builds

• Stores Jenkins job configurations

• Monitors agents' statuses

2️⃣ Jenkins Agents (Workers)

• Execute the actual jobs on distributed nodes

• Can be on Linux, Windows, Kubernetes, Docker

• Reduces load on the master

3️⃣ Jenkins Components

Component	Description
Jobs	Defines tasks like build, test, deploy
Pipelines	Automate CI/CD using scripts
Plugins	Extend Jenkins functionality (e.g., Docker, Git)
Webhooks	Trigger builds on code changes
Artifacts	Stores built files (e.g., JARs, Docker images)
Credentials	Securely store SSH keys, API tokens
Blue Ocean	Modern UI for visual pipelines

4️⃣ Jenkins Workflow

1. Developer commits code → GitHub Webhook triggers Jenkins

2. Jenkins pulls latest code and starts a pipeline

3. Build and test stages execute on agents

4. Artifacts are stored (Docker image, JAR, etc.)

5. Jenkins deploys to Kubernetes, AWS, or on-prem servers

6. Notifications sent via Slack, Email on build status

5️⃣ Jenkins on Kubernetes

• Runs Jenkins in Kubernetes as a Pod

• Uses Jenkins Helm Chart for deployment

• Agents scale dynamically using Kubernetes auto-scaling

6️⃣ Jenkins Distributed Builds

• Jenkins Master assigns jobs to multiple agents

• Parallel execution improves speed

• Agents can be in Docker, AWS, or Bare Metal servers

---

🚀 Conclusion

Jenkins is a powerful CI/CD tool with a distributed architecture that integrates seamlessly with Git, Docker, Kubernetes, AWS, and monitoring tools.