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🚀 Golang CI/CD with Jenkins, Docker, Helm, and OpenShift

This repository demonstrates a full CI/CD pipeline for a Golang application, showing how code changes are built, containerized, and deployed to an OpenShift cluster using modern DevOps tools.

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📁 Project Structure

.
├── app/                     # Go application code & Dockerfile
│   ├── main.go
│   ├── go.mod
│   ├── go.sum
│   └── Dockerfile
│
├── k8s/helm-chart/          # Helm chart for OpenShift deployment
│   ├── Chart.yaml
│   ├── values.yaml
│   └── templates/
│       ├── deployment.yaml
│       ├── service.yaml
│       └── route.yaml
│
└── Jenkinsfile              # Jenkins CI/CD pipeline definition

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🔁 CI/CD Pipeline Overview

The pipeline is orchestrated using Jenkins, triggered via GitHub Webhooks on commits to the main branch.

✅ Continuous Integration (CI)

1. Trigger: GitHub push event (via webhook).
2. Build: Compiles the Go application as a static binary.
3. Dockerize: Creates a lightweight image using a multi-stage Dockerfile.
4. Push: Publishes the image to Docker Hub (tusk03/golang-app).

🚀 Continuous Delivery (CD)

1. Login: Jenkins authenticates with OpenShift via CLI (oc login) using a secret token.
2. Deploy: Runs helm upgrade --install using the chart in k8s/helm-chart/.
3. Expose: OpenShift Route exposes the service (similar to Ingress in Kubernetes).

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🛠️ Technologies Used

Tool/Platform	Purpose
Go (Golang)	Application logic
GitHub	Source control
Jenkins	CI/CD pipeline automation
Docker	Containerization of app
Docker Hub	Container registry
Helm	Kubernetes/OpenShift deployment
OpenShift	Container orchestration platform

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🧩 Troubleshooting & Key Learnings

Building this pipeline involved solving several real-world DevOps issues:

🔹 1. Docker Build Context Error

• Error: go.mod not found, or unable to prepare context.
• Fix: Reorganized project so the Dockerfile and Go files live inside /app. Updated docker build path to ./app in Jenkinsfile.

🔹 2. DockerHub Credential Issue

• Error: Jenkins failed to push image to Docker Hub.
• Fix: Corrected withCredentials block in Jenkinsfile using usernamePassword for DockerHub credentials.

🔹 3. OpenShift Token Expired

• Error: oc login: token invalid or expired.
• Fix: Generated a fresh token from OpenShift Console and updated Jenkins credentials.

🔹 4. Helm Chart Not Found

• Error: Chart.yaml file is missing.
• Fix: Corrected the path to ./k8s/helm-chart and ensured file is named Chart.yaml (case-sensitive).

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✅ Outcome

By the end of this CI/CD pipeline:

• A new Go binary is compiled and containerized automatically.
• Docker image is pushed to your registry.
• Helm deploys the updated image to your OpenShift cluster using rolling upgrades.
• The app is available via a public OpenShift Route.

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