Jenkins — Prerequisites

What to Know Before Starting Jenkins

Jenkins is a CI/CD automation server. You're building pipelines that test, build, and deploy code. These foundations prevent confusion.

Required

1. Git — Must Know Well

Jenkins triggers on Git events (push, PR). You must know:

bash

git clone, git add, git commit, git push
git branch, git checkout, git merge

Jenkins reads Jenkinsfile from your repository. If Git is unfamiliar, learn it first (2-3 days).

2. Basic Linux/Bash

Jenkins pipelines run shell commands. You need to read and write:

bash

# Commands you'll use in Jenkinsfiles:
sh 'npm install'                   # Run shell command
sh 'docker build -t myapp:${BUILD_NUMBER} .'
sh 'kubectl apply -f deployment.yaml'
echo "Build number: ${env.BUILD_NUMBER}"

3. Understanding of the Application Being Built

Jenkins builds YOUR application. If you don't understand how to build it manually, Jenkins can't help. Know how to:

•Build a project locally (e.g., npm run build, mvn package, go build)

•Run tests locally (npm test, pytest, go test)

•Build a Docker image (docker build -t myapp .)

4. Docker Basics

Modern Jenkins uses Docker agents — each pipeline stage runs in a fresh Docker container. You should understand:

•What a Docker image is

•docker build, docker run, docker push

•docker-compose basics

Nice to Have

Groovy Basics (Not Required, Helpful)

Jenkinsfiles are written in Groovy DSL. You don't need to know Groovy deeply, but understanding variables and conditions helps:

groovy

def version = "1.0.${BUILD_NUMBER}"
if (env.BRANCH_NAME == 'main') {
    // deploy to production
}

The Application's Testing Framework

Jenkins typically runs tests. Knowing how your app's tests work (Jest, pytest, JUnit) helps you configure test reporting.

A Cloud Account or Kubernetes Cluster

Jenkins pipelines deploy somewhere. Having an EKS/AKS cluster or EC2 instances to deploy to gives you a complete learning experience.

Learning Order

Git (if needed) ← 3-5 days
      ↓
Docker basics ← 1-2 weeks
      ↓
Jenkins Installation
      ↓
Jenkins Fundamentals (first pipeline)
      ↓
Intermediate (Docker agents, credentials, tests)
      ↓
Advanced (shared libraries, K8s agents, production patterns)

Time Estimate

With the prerequisites:

•Create your first working pipeline: 1-2 days

•Pipeline with tests, Docker build, deploy: 1 week

•Production-grade shared library: 3-4 weeks