DevOps Classroom Series – 27/Sept/2020

Jenkins Administrative Activies

• Install the following Plugins

  • Dashboard View
  • Monitoring
  • Audit Trail
  • Disk-Usage Plugin
  • Backup plugin

• Backing up and restoring Jenkins:

  • After Installing plugins. Navigate to Manage Jenkins and search for backup plugins
  • Once the backups are taken then we get the restore options.
  • Also explore thin backup plugin

• Managing disk usage

  • Navigate to Manage Jenkins and Navigate to Disk Usage
  • Now Navigate to Manage Jenkins => Configure System
  • Now Navigate to Jenkins Home & Select Disk Usage
  • Navigate to any project where you have build the jenkins job

• Preparing Jenkins for Shutdown

  • Navigate to Manage Jenkins

• Monitoring of Jenkins Master

• Configuring email notifications:

  • Refer here
  • Mailtrap seems to be good for testing mails Refer Here

• Jenkins needs to be used from cli by writing commands, For this we have two options

  • Jenkins CLI
  • Call Jenkins Rest API using curl command
    • In the Jenkins footer we have a link to jenkins REST API
    • Refer Here for jenkins remote api docs

• User Management in Jenkins:

  • Jenkins Provides the following options for configuring users (Authentication)
    • Jenkins Database (Allow Signup)
    • Jenkins & OpenLDAP Integration
    • Jenkins & Active Directory Intergation
  • Configuring Authorization using Matrix Based Security
  • Let change authorization to Matrix Based security

Scenario: Learning Thoughts Jenkins Configuration

• Learning Thoughts has 3 Business Units
  • HRMS:
    • Hosted on Ubuntu Linux
    • Developed in Java
  • HMS
    • Hosted on RedHat Enterprise Linux
    • Has Java, Python & Node Js as this project is result of multiple acquistions
  • LMS
    • Hosted on Windows Server
    • Developed in .net
• As a DevOps Engineer of Learning Thoughts, Don is supposed to build, provide all environments and deploy all the applications to production when needed
• As of Now Learning Thoughts Wants to use the Jenkins for CI/CD pipelines.
• How can Don manage this?
  • Manage Different Jenkins Masters
    • Jenkins Master for HRMS
    • Jenkins Master for HMS
    • Jenkins Master for LMS
    • But this is already sounding like a stupid approach.
  • To Solve these kind of problems Jenkins supports Distributed Builds.
• Distributed Build Terms
  • Masters
  • Node
  • Agents
  • Executors
  • Labels
• Jenkins is collection of Nodes. Each Node represents a Physical or a virtual machine. Nodes are of two types
  • Master
  • Agent
• Master to Agent communication can happen via
  • SSH: Configure Linux, Mac & Unix Nodes
  • JNLP: Configure Windows Nodes.
• On Every Agent we would have a Remote Working Directory

Lets Create a Jenkins Distribute Build Environment for Learning Thoughts

• Our setup would be

  • Jenkins Master:
    • Ubunutu 20 Machine (AWS)
    • Executor: 1
    • Labels: Master
    • Software:
      • Java
      • Git
  • Jenkins HRMS QA Node
    • Ubunutu 18 Machine (AWS)
    • Software Set:
      • Git
      • JAVA 8
      • MAVEN 3.6.3
    • Labels:
      • HRMS
      • QA
    • Executors: 2
    • Project: Gameoflife

• Master Configuration:

  • Install Jenkins
  • Navigate to manage jenkins

• Jenkins HRMS QA Node configuration

  • Login into the machine and create a new user called as jenkins (In your org you might be using service accounts)

  sudo -i
  adduser jenkins
  vi /etc/ssh/sshd_config
  # change PasswordAuthentication from No to yes
  service sshd restart
  # add sudo previleges with NOPASSWD if required
  

  • Install Java
  • Install Maven

• Now lets configure this node as agent to jenkins master

  • Try logging in from jenkins user on master node to agent
  • Navigate to Manage Jenkins => Manage Nodes and add a new node

• Lets create a build job for lthrmsqa

• Now configure any java project to build, show test results and archive the artifacts

• Now build the project & observe on which node & executor the project got scheduled