Pipeline.md

Jenkins Pipeline:

pipeline {
    agent any

    stages {
        stage('Build Docker Image') {
            steps {
                sh 'docker build -t sbhusal123/django-app:latest .'
            }
        }
        
        stage('Push Docker Image To Registry') {
            steps {
                // username and password secret to be set
                // credentialsId: dockerhub_credentials
                withCredentials(
                    [usernamePassword(
                        credentialsId: 'dockerhub_credentials', 
                        usernameVariable: 'DOCKERHUB_USERNAME', 
                        passwordVariable: 'DOCKERHUB_PASSWORD'
                    )]
                ) {
                    sh 'echo "$DOCKERHUB_PASSWORD" | docker login -u "$DOCKERHUB_USERNAME" --password-stdin'
                    sh 'docker push sbhusal123/django-app:latest'
                }
            }
        }

        stage('Rollout Deployment') {
            steps {
                
                // secret text credentials to be set
                withCredentials([
                    string(credentialsId: 'ssh_user', variable: 'SSH_USER'),
                    string(credentialsId: 'ssh_host', variable: 'SSH_HOST'),
                    string(credentialsId: 'git_repo_url', variable: 'REPO_URL')
                ]) {
                sshagent(['kube_ssh_key']) {
                        sshagent(['kube_ssh_key']) {
                            // note the indentation must be as below for EOF delimiter
                            sh """
        ssh -o StrictHostKeyChecking=no ${SSH_USER}@${SSH_HOST} <<EOF
if [ -d django-kubernetes-deployment ]; then
    cd django-kubernetes-deployment
    git pull
else
    git clone ${REPO_URL} django-kubernetes-deployment
    cd django-kubernetes-deployment
fi
make run
make rollout_deployment
EOF
                            """
                        }
                }

                }
            }
        }
    }
}

In the very first step:

1. Builds a docker image and tags it.

2. Pushes docker image to registry.

Note that this steps requires Username and Password credentials setup with docker username and token as password. Credentials id must be dockerhub_credentials

3. In this step.

   3.1. Jenkins ssh into a kubernetes server. This requires a sshagent plugin and SSH Username with private key credential with credentials id kube_ssh_key.

   3.2. Also requires a three Secret text Credentials with id: ssh_user ssh_host git_repo_url

Then pipeline ssh's into the kubernetes server using kube_ssh_key, ssh_host, ssh_user credentials and clones the repo using git_repo_url credentials.

                // secret text credentials to be set
                withCredentials([
                    string(credentialsId: 'ssh_user', variable: 'SSH_USER'),
                    string(credentialsId: 'ssh_host', variable: 'SSH_HOST'),
                    string(credentialsId: 'git_repo_url', variable: 'REPO_URL')
                ]) {
                sshagent(['kube_ssh_key']) {
                        sshagent(['kube_ssh_key']) {
                            // note the indentation must be as below for EOF delimiter
                            sh """
        ssh -o StrictHostKeyChecking=no ${SSH_USER}@${SSH_HOST} <<EOF
if [ -d django-kubernetes-deployment ]; then
    cd django-kubernetes-deployment
    git pull
else
    git clone ${REPO_URL} django-kubernetes-deployment
    cd django-kubernetes-deployment
fi
make run
make rollout_deployment
EOF
                            """
                        }
                }

                }