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Unit 1

Jenkins is a very powerful Build Engine used in CI/CD. What makes it powerful is the set of plugins and its integration with a lot of other tools including Docker.

Presented by – Seshagiri Sriram

Getting Started with Jenkins and CI/CD powered by Docker

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Agenda

A quick overview of CI/CD
Benefits of Jenkins
Jenkins Eco-System
Installation of Jenkins
Integrating Jenkins with GitHub
Creating your first pipeline
Automating the Build/Test/Deploy Pipeline
Items marked in yellow are covered in Hands On Lab

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What is CI/CD

Martin Fowler defines Continuous Integration (CI) as
A Software Development Process where
Every team member merge their changes along
With changes from other team members
At least once daily
Each of these integrations are verified by automated builds
(including Tests)
To detect errors early on in the process

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Do we have data?

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Source: http://www.agitar.com/solutions/why_unit_testing.html

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CI – The origins

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A basic flow for CI

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JENKINS

GITHUB

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CI vs Build Management

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CI is not just Compiling Code!

CI is not the same as a build
The latter term is used for compilation only
CI includes

Compilation
Running Unit tests
Generating Documents and Reports
Integrating Databases
Running System/Integration/Regression/Security Test
Integrate with Continuous Delivery (CD) for deployment

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Simplified CI/CD Pipeline

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Commit Code

Unit and Integration Test

Continuous Integration

Deploy to Test Environment

Acceptance Testing

Continuous Delivery

Deploy to Production

Continuous Deployment

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Continuous Integration Basics

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Dedicated Build Server

Developer Workstations

Code Changes

Version Control Server

Integration Server

Test Server

UAT Server

Production Server

Auto Deployment Process

Compilation
Test Execution
Database integration
Code inspection
Automated Deployment
Document Generation

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So can I use Jenkins as is?

Yes
However to be effective

You need defined processes & tools for Version Control
You should have automated test cases ready
You need defined processes & tools for building and deployment
You need JENKINS

All should be scriptable.
Very Minimal GUI/user interaction

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Alternatives to Jenkins

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Hudson

NB: Hudson later became Jenkins

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Why Jenkins?

Open Source
Commercial and Enterprise Edition/Support available
Extensible with over 1000+ plugins for integration
Can be extended with custom plugin if required
Easy to Install
Can be run as Docker Container
Can be used with most programming languages
Web based Admin

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Jenkins Plugins

The of Jenkins are plugins.

Jenkins has over 800+ Plugins.

It was over 1000, but many have been pruned and merged for better user experience

See here: https://plugins.jenkins.io/

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One way of looking at plugins

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Plugins

SCM

Build Triggers

Build Tools

Build Wrappers

Notifiers

Report Plugins

Plugins

Slave Controllers

Artifacts Uploaders

UI Plugins

List View Column Plugins

External Tool Integrators

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Plugins

The system administrator can choose what plugins to install.
Note that plugins can be uninstalled at any time

A good way to learn about each plugin

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A Note on Jenkins Practice

When installing, we choose default plugins when first exploring Jenkins
On first Login, Navigate to Manage Jenkins->Plugins and update all plugins (esp. If installing as a Java WAR file)

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Plugins vs Build Tools

Jenkins does not compile or test code itself.
It provides support for these via Tools where the administrator installs

Java
Maven
Ant
… Some other java related tools
GIT clients
…

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Plugins vs Build Tools

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A Note on Jenkins Practice

Rather than configuring these tools in the main Jenkins server, these are usually delegated to docker images that contain these tools
Another approach (preferred) is to delegate these tasks to a slave node.

A Note on Jenkins Practice

The 1^st time Jenkins is launched, it has no security.
DO NOT EXPOSE URL to the rest of the world before setting security.

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Lab Time

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Masters & Slaves

The Jenkins Server is considered a master node.
Its label is set to Docker to enable it to spin a docker container on demand.
Sometimes, it may be necessary to have tasks be run on a dedicated machine e.g. Windows apps.
Such nodes are designated Jenkins Slaves.

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Masters and Slaves

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Masters & Slaves

The only considerations are

Masters and slaves should be as close as possible in network
SSH communication should be enabled between the master and slave
Install the required plugins

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Masters & Slaves

The only considerations are

Masters and slaves should be as close as possible in network
SSH communication should be enabled between the master and slave
Install the required plugins

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Masters & Slaves

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Masters & Slaves

On the Slave (Java),

Install Java and Jenkins Slave Jar
Copy over Masters’ Public Key to authorized_keys file under .ssh

On Master,

Create a SSH credential for user running the agent
Add the user’s public key to the authorized_keys
Validate that ssh commands do not ask for password or prompts
Now configure the nodes to use the credential and assign jobs to the slave nodes.

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Q &A

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We're done!

Thank you for your time and participation.