DevOps Project for Beginners | End-to-End CI/CD Pipeline Using Jenkins, Docker & GitHub

CI/CD Pipeline Project (Jenkins + GitHub + Docker + Docker Hub)

Architecture / end-to-end flow (no manual steps)

• Developer writes code in VS Code, adds features/tests locally, then pushes commits to GitHub.
• GitHub acts as the central code repository and detects new changes.
• Webhook → Jenkins: GitHub sends a webhook notification to Jenkins to start the pipeline automatically (described as a “messenger” for triggering builds).
• Jenkins stages:
  1. Build stage: compiles the app, downloads dependencies, processes source code, and produces a production-ready artifact.
  2. Docker build stage: creates a Docker image containing the application + dependencies so it runs consistently across environments.
  3. Push to Docker Hub: Jenkins pushes the Docker image to Docker Hub (a central image registry with versioning).
  4. Deploy stage: on the server, Jenkins pulls the latest image, stops/removes the old container with the same name, and runs a new container (detached mode) exposing port 3000. Users can verify via localhost:3000 without manual file copy/login.

What the tutorial focuses on

• A complete “real-time” DevOps CI/CD pipeline for beginners.
• Hands-on setup of the tooling locally (or via a cloud VM):
  • Ubuntu environment (minimum: 4GB RAM, 2 CPU, 20GB free disk).
  • Install: Jenkins, Docker, Git, Node.js (plus GitHub and Docker Hub accounts).
• Creation and storage of app code in GitHub:
  • Initializes a repo, commits files, and pushes app.js, package.json, and a Dockerfile.
• Jenkins configuration:
  • Ensures required Jenkins plugins are installed (notably pipeline/Docker-related).
  • Adds credentials for:
    • Docker Hub (username/password) using a credential ID
    • GitHub repo access (username/password) using a separate credential ID
• Jenkinsfile usage:
  • Pipeline checks out from GitHub main branch
  • Builds Docker image using: docker build -t $imageName:latest .
  • Logs in to Docker Hub using stored Jenkins credentials
  • Pushes with: docker push $imageName:latest
  • Deploys by stopping old containers and running a new one with: docker run -d ... -p 3000:3000 ...

Review / guide / tutorial notes included

• The guide provides a requirements checklist and step-by-step installation commands (e.g., installing Java/OpenJDK first, then Jenkins).
• Notes that Jenkins requires Java; if versions change, learners should copy the latest command from the official site.
• Jenkins install completion steps include:
  • Use localhost:8080
  • Copy initial admin password from the terminal using cat of the Jenkins secrets file
  • Install “suggested” plugins
• Jenkins execution and triggering:
  • Pipeline is run manually initially (“Build Now”).
  • It will not trigger automatically unless a GitHub webhook is configured (webhook configuration is deferred to an upcoming session).

Key commands / configuration ideas highlighted

• Jenkins service checks: sudo systemctl status Jenkins

• Docker install and version checks: sudo apt install docker.io -y then docker --version

• Allow Jenkins to use Docker:

  • Add Jenkins user to Docker group (shown as sudo usermod -aG Docker and Jenkins in subtitles)
  • Restart Docker and Jenkins
• Git setup workflow:
  • git init
  • add/commit
  • set remote
  • git push
• Dockerfile concept:
  • Base image: node:20-alpine
  • Copy package.json, install dependencies, copy app code
  • Run Node app on 3000 (via npm start / Express)
• Jenkinsfile variables/configuration:
  • Image name based on Docker Hub repo/image name
  • Container name fixed (e.g., node.js app)
  • Uses Jenkins credentials via credentialsId-style references (as described)

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Main speakers / sources

• Speaker: “DevOps Z plus tutorials” (project creator/instructor introducing the tutorial; no individual name given in subtitles).
• Primary referenced sources: Official documentation for Jenkins and OpenJDK/Java; tooling providers GitHub, Jenkins, Docker, Docker Hub.