Jenkins

What is Jenkins?

Jenkins is an open-source automation platform that allows you to Build, Test and Deploy software using pipelines.

• It helps software teams facilitate Continuous Integration and Continuous Deployment / Delivery.
• Jenkins is highly extensible
  • There are hundreds of plugins

Why do we need Jenkins?

• Developers making code changes in parallel want to make sure that their changes integrate without errors.
• Developers also want their changes built and tested in a standardised environment.

Jenkins Installation Methods

• Run from a WAR (Web Application Resource) file
• Run as a Docker container
• Install on Windows
• Install on MacOS
• Install on Linux

Jenkins Infrastructure

• Master server
  • Controls Pipelines
  • Schedules Builds
• Agents
  • Perform the build

Agent Types

• Permanent agent
  • Dedicated Servers for Running Jobs
  • Java and SSH installed (passwordless authentication)
  • Also install any build tools needed

• Cloud Agents
  • Ephemeral / Dynamic Agent spun up on demand
  • Example: Docker, Kubernetes, AWS

Build Types

• Freestyle Build
  • Simple and easy to run
  • Similar to shell scripting
• Pipeline
  • Use Groovy syntax
  • Run in stages

Jenkins folder location

/var/lib/jenkins

GitHub and Jenkins Integration Benefits

• Ability to clone a codebase down to the local jenkins workspace
• GitHub pushes new changes
• Jenkins can perform GitHub operations
  • Build result published to GitHub Pull
  • Requests and Commits

Integration Prerequisite

• GitHub must be able to send data to Jenkins
• Jenkins must have a public IP
• Except for on-premise GitHub instance