🚀 From Manual to Automated: My Jenkins-Powered CI/CD Journey

DevOps isn't just about deploying code — it's about doing it reliably, repeatedly, and automatically. Over the past several days, I transformed my knowledge of Jenkins from theoretical to fully practical by building automation pipelines, exploring agent configurations, and finally implementing a complete CI/CD system for a real project.

Here’s how it unfolded 👇

💡 Understanding Jenkins & CI/CD Concepts

My journey started with understanding the core purpose of Jenkins — a powerful open-source tool to orchestrate Continuous Integration and Delivery.

I explored:

• The Jenkins UI and how to configure jobs

• Different types of jobs: freestyle vs. pipeline

• How Jenkins connects with GitHub via webhooks

• How Jenkins works internally: master-slave (controller-agent) architecture

• Use of console logs to debug pipeline execution

One of the coolest parts was watching a Jenkins job trigger automatically the moment I pushed code to GitHub — magic backed by webhooks and pipelines.

🔧 Declarative Jenkins Pipelines

Next, I moved into writing Declarative Pipelines using the pipeline { ... } syntax.

What I learned:

• How to define stages like Build, Test, Push, and Deploy

• The power of post blocks to handle notifications

• How Jenkins handles failures and visualizes builds

• How to add credentials for Docker Hub securely

These concepts made me realize Jenkins isn’t just a tool — it's a language for automating workflows.

🔄 Jenkins + GitHub Integration

I configured:

• A GitHub webhook to auto-trigger builds on push

• SCM Polling as a backup trigger method

• Used Declarative Pipelines with embedded GitHub repo references

• Stored sensitive data (like DockerHub credentials) using Jenkins credentials manager

This setup gave me the confidence to automate even more complex flows without human intervention.

🧪 Automating Docker Image Builds & Push

Once the pipeline was stable, I introduced:

• Multi-stage Dockerfile to ensure production-grade builds

• Pipeline stage to build Docker image

• Another stage to push the image to Docker Hub

This drastically reduced the manual effort I had to do after every code change — no more docker build, docker tag, and docker push from my terminal.

🔁 Auto Deployment with Docker Compose

With Jenkins pushing the latest image to Docker Hub, the next step was automated deployment:

• Jenkins remotely executed docker-compose pull and docker-compose up -d to deploy the latest version

• No SSH, no terminal, no downtime — just automation.

This completed my CI/CD flow from code commit → deployment 🚀

📬 Bonus: Email Notifications with post Block

To make the pipeline even more production-ready, I added:

• An email notification at the end of the pipeline

• Configured it inside the post { success { ... } } block

It gave me real-time feedback whenever the deployment succeeded, directly in my inbox.

🛠️ Final Project: CI/CD for Online Shop App

To bring all the above concepts into a real use-case, I extended my Online Shop Project with a Jenkins-based CI/CD pipeline.

🔨 Technologies Used:

• Jenkins

• Docker & Docker Compose

• GitHub Webhooks

• Docker Hub

• Email Notification

🔗 Project Highlights:

• Branch: project

• Contains: Jenkinsfile, Dockerfile, docker-compose.yml, and CI/CD logic

• Pipeline Flow:

  • Push to GitHub

  • Auto-trigger via webhook

  • Checkout → Build → Push image → Deploy → Notify via email

This wasn’t just practice — it was my first end-to-end real-world pipeline automation!

🙌 What I Took Away

🔹 Writing pipelines helped me think like a DevOps engineer, not just a coder
🔹 Jenkins is more than a CI tool — it’s the engine of automation
🔹 CI/CD is all about making things faster, safer, and repeatable

💭 What's Next?

Up next: DEVSECOPS, and possibly deploying to the cloud. The foundation is set — now it’s time to scale it up! 🌍

🔖 Tags:

#Jenkins #DevOps #CI_CD #Automation #Docker #GitHub #DockerHub #OnlineShop #TrainWithShubham #LearnInPublic #90DaysOfDevOps