DevOps Classroom Series – 17/May/2020 – Direct DevOps from Quality Thought

One More interesting groovy snippet to make us understand step synax

Steps use the shorthand notation for mapping syntax in Groovy

def printmessage(Map config=[:]){
   println("message is ${config.message} and author is ${config.author}")
}

printmessage message: "How are you", author: "Khaja"
printmessage message: "Doing good", author: "Anonymous", test: true

Now Lets Navigate to Here for git steps

git "https://github.com/shaikkhajaibrahim/spring-petclinic.git"
# only required option

git url: "https://github.com/shaikkhajaibrahim/spring-petclinic.git", branch: "Dev"

For complete list of steps Refer Here

Triggers using Pipelines

Build Triggers used in the free style project can be defined from pipeline as well
Refer Here for official docs
In this lets assume we have a project in jenkins called as dummy. lets write the declarative pipeline to trigger the current project jenkins build after succesful execution of dummy project, the syntax of pipleine will be

pipeline {
    agent any
	triggers {
	   upstream(upstreamProjects: 'dummy', threshold: hudson.model.Result.SUCCESS)
	}
    stages {
        stage('Source'){
            steps {
                git 'https://github.com/dummyrepos/spring-petclinic.git' 
            }
        }
        stage('Package'){
            steps {
                sh 'mvn package'
            }
        }
    }
}

The console output of dummy project looks like
If we navigate to our projects (declarative spc) view

Build Jobs from post build of upstream

From free style project Navigate to postbuild and then build the projects
From Jenkinsfile you can use build step of pipeline

Taking inputs from users in between build

Lets take the input from the user to continue to next step
Refer Here for documentation
pipeline after making changes

pipeline {
    agent {label 'MASTER'}
	triggers {
	   upstream(upstreamProjects: 'dummy', threshold: hudson.model.Result.SUCCESS)
	}
    stages {
        stage('Source'){
            steps {
                git 'https://github.com/dummyrepos/spring-petclinic.git' 
            }
        }
        stage('Package'){
            steps {
                sh 'mvn package'
				input 'continue to next step?'
				archiveArtifacts 'target/*.jar'
            }
        }
    }
}

Screenshot of approval

Parameters in Jenkins

In Free style projects
In declarative pipeline, we have parameters section Refer Here, pipleline after adding one string parameter looks as shown below

pipeline {
    agent {label 'MASTER'}
	triggers {
	   upstream(upstreamProjects: 'dummy', threshold: hudson.model.Result.SUCCESS)
	}
	parameters {
		string(name: 'BRANCH_FOR_BUILD', defaultValue: 'master', description: 'Enter the branch to be built')
	}
    stages {
        stage('Source'){
            steps {
                git url: 'https://github.com/dummyrepos/spring-petclinic.git', branch: "${params.BRANCH_FOR_BUILD}"
            }
        }
        stage('Package'){
            steps {
                sh 'mvn package'
				
            }
        }
    }
}

This pipeline will change the jenkins build of the project as shown below
Also refer to the options section Refer Here

Frequently used Steps in Jenkins

Notifications: Refer Here

Stash Refer Here and unstash Refer Here

Refer Below example for stash and unstash

pipeline {
    agent any
    stages {
        stage('build') {
            agent {label: 'MAVEN'}
            steps {
            
                
                git url: 'https://github.com/dummyrepos/spring-petclinic.git'
                sh 'mvn package'
                stash name: 'spc-jar', includes: 'target/spring-petclinic.jar'
            }
            
        }
        
        stage('deploy') {
            agent {label: 'Ansible'}			
            steps {
                unstash 'spc-jar'
                git url: 'https://github.com/dummyrepos/spring-petclinic-ansible.git
                sh 'ansible-playbook -i hosts deploy.yaml'
            }
            
        }
    }
}

Build Promotions using Maven Repository (Artifactory)

Refer Here for configuring artifactory
Project which we build from ci/cd will create some artifacts and they need to preserved for future usage.
But how do i preserve the builds, we need repository for storing binary file. For that there are lot of options
- Network Drives (Shared Drives) => Every day after build is completed in jenkins copy the build to some network drive
- Cloud Storage like S3 or Azure blob storage
- JFrog(Artifactory)
- Nexus
In this series we will be using Artifactory, Refer Here for installation
So our story with artifacts look as shown below
Navigate to artifactory post installation on port 8081 and you will be asked to reset password and then select the repository
Setting up for settings.xml to be downloaded
Make changes in settings.xml and copy the file to ~/.m2/settings.xml and do mvn package for some project
Maven goal install will copy the artifact and pom.xml into ~/.m2/repository/<suitable> and maven goal deploy will copy the the artifact and pom.xml in the remote repository
- Install will copy into ~/.m2 (env M2_HOME)
- To deploy the artifact we need to make changes in pom.xml Refer here
Doing the same (Resolving and deploying from jenkins) Refer the Document
Refer Here for pipeline Jenkins job and Refer Here for examples