Guide to CREATE A CICD Pipeline on Jenkins Using Docker & Ansible

Step1 -- Pre-Requisite

      Create a VM (on any cloud OR Virtual Box) with 1CPU 2GB RAM

      login to the VM Install below tools

Step2 -- Install Java & Jenkins

# follow instruction from below

https://github.com/lerndevops/labs/blob/master/jenkins/Install/README.md 

Step3 -- Install Maven

# follow instruction from below

https://github.com/lerndevops/labs/blob/master/jenkins/Install/README.md 

Step4 -- Install Docker

sudo wget https://raw.githubusercontent.com/lerndevops/labs/master/scripts/installDocker.sh -P /tmp
sudo chmod 755 /tmp/installDocker.sh
sudo bash /tmp/installDocker.sh

Step5 -- Install Ansible

sudo wget https://raw.githubusercontent.com/lerndevops/labs/master/scripts/installAnsible.sh -P /tmp
sudo chmod 755 /tmp/installAnsible.sh
sudo bash /tmp/installAnsible.sh

# modify the ansible config file to ensure disable host key checking 
cd /etc/ansible/
ansible-config init --disabled > ansible.cfg
vi /etc/ansible/ansible.cfg 

# uncomment this to disable SSH key host checking
host_key_checking = False

Step6 -- Login to Jenkins UI

hit http://IP:8080 in browser ## incase of cloud please use Public IP ensure the Port is allowed to access

	enter `initialAdminPassword` the page to login ( cat /var/lib/jenkins/secrets/initialAdminPassword )

	click on `Install Suggested Plugins`
	
	continue next and finish the setup. 

Step7 -- Install reqired Plugins (Install from Jenkins UI)

install all these from Jenkins UI 

  Manage Jenkins --> manage plugins -- Available -- search & install the below
  	1) warnings NG
  	2) jacoco
  	3) Junit
  	4) Build Pipeline
  	5) Docker Piepeline

Step8 -- Create Credentials (Setup from Jenkins UI)

  Manage Jenkins -->  Manage Credentials ==> Stores scoped to Jenkins - global ==> Add Credentials 
	--> kind: username with password 
	--> scope: Global
	--> username: <enter your docker hub id>
	--> password: <enter your docker hub password> 
	--> ID: DOCKER_HUB_LOGIN 
	--> Description: DOCKER_HUB_LOGIN

Step9 -- Configure JAVA - MAVEN - Git (Setup from Jenkins UI)

Java configuration in Jenkins console 
	
	Manage Jenkins --> Global Tool Configuration --> JDK --> Add JDK
		Name: myjava ( can be any string )
		JAVA_HOME: /path/to/javahome ( ex: /usr/lib/jvm/java-8-openjdk-amd64 )

Maven Configuration in Jenkins console
	
	Manage Jenkins --> Global Tool Configuration --> Maven --> Add Maven
		Name: maven3.6 ( can be any string )
		MAVEN_HOME: /path/to/mavenhome ( ex: /opt/apache-maven-3.6.5 )

Git Configuration in Jenkins console
	
	Manage Jenkins --> Global Tool Configuration --> Git --> Add Git
		Name: git ( can be any string )
		MAVEN_HOME: /path/to/githome ( ex: /usr/bin/git )

Step10 -- configure Jenkins with Docker - from Jenkin Server CLI

by default Jenkins process runs with Jenkins User, which mean any jenkins Jobs we run from jenkins console will be running jenkins user on Jenkins machine

we need to configure Jenkins user can run the docker commands by adding jenkins user to docker group

    sudo usermod -aG docker jenkins

restart the Jenkins Service

    sudo service jenkins restart

validate, run docker command with jenkins

	su - jenkins           ## switch to jenkins user
	docker ps              ## to list any containers running
	docker pull nginx      ## pull a docker image 

if the above commands execute without any error then we configured jenkins user properly

Step11 -- Setup Deployment Environments

setup atleast one docker swarm / kubernetes cluster

  create two VMs for QA, Install the required toos & setup the kubernetes cluster, one master - one worker node

Step12 -- Setup Ansible Inventory on Jenkins machine using CLI

   vi /tmp/inv 
      enter your servers in groups like qa & prod 
   sudo chmod 755 /tmp/inv
   sudo chown jenkins:jenkins /tmp/inv
 
   // look at the sample inventory file under https://raw.githubusercontent.com/lerndevops/PetClinic/master/deploy/inv 
   
   Note: ensure to put only manager IPs in inventory file -- DO NOT PUT NODE IPs

Step 13: Now Let's start creating CICD Pipeline Using Pipeline As Code Script

Jenkins ( home page )

  --> Click on New Item from left menu 
  --> Enter an item name: CICD-Pipeline 
  --> Choose: Pipeline 
  --> Click: ok

insdie job parameters as below

-->  Click on Pipeline (TAB) on top 
-->  Definition (drop down): Pipeline Script from SCM
-->  SCM (drop down): Git
-->  Repositories --> Repositories URL --> https://github.com/lerndevops/PetClinic
-->  leave the other values Default for this Demo
-->  Script Path: cicd.gvy 
	--> Note: Script is already availabe at https://github.com/lerndevops/PetClinic/blob/master/cicd.gvy
-->  Click on Save 
-->  Build Now from left Menu