Tuesday, June 9, 2020

Deploy Python App into Kubernetes Cluster using Jenkins Pipeline | Containerize Python App and Deploy into AKS Cluster

We will learn how to automate Docker builds using Jenkins and Deploy into Kubernetes Cluster setup using AKS. We will use Python based application. I have already created a repo with source code + Dockerfile. The repo also have Jenkinsfile for automating the following:

- Automating builds using Jenkins
- Automating Docker image creation
- Automating Docker image upload into Docker registry
- Automating Deployments to Kubernetes Cluster

Pre-requistes:
1. AKS Cluster is setup and running. Click here to learn how to create AKS cluster.
2. Jenkins Master is up and running. 
3. Setup Jenkins slave to run Docker builds
4. Docker, Docker pipeline and Kubernetes Deploy plug-ins are installed in Jenkins



5. Docker hub account setup in https://cloud.docker.com


Step #1 - Create Credentials for Docker Hub
Go to Jenkins UI, click on Credentials -->


Click on Global credentials
Click on Add Credentials


Now Create an entry for your Docker Hub account. Make sure you enter the ID as dockerhub

Step #2 - Create Credentials for Kubernetes Cluster
Click on Add Credentials, use Kubernetes configuration from drop down.


execute the below command to get kubeconfig info, copy the entire content of the file:
sudo cat ~/.kube/config


Enter ID as K8S and choose enter directly and paste the above file content and save.

Step # 3 - Create a pipeline in Jenkins
Create a new pipeline job.


Step # 4 - Copy the pipeline code from below
Make sure you change red highlighted values below:
Your docker user id should be updated.
your registry credentials ID from Jenkins from step # 1 should be copied

pipeline {
     agent {
         label 'myslave'
     }
        environment {
        //once you sign up for Docker hub, use that user_id here
        registry = "your_docker_hub_user_id/mypython-app"
        //- update your credentials ID after creating credentials for connecting to Docker Hub
        registryCredential = 'dockerhub'
        dockerImage = ''
    }
    stages {

        stage ('checkout') {
            steps {
            checkout([$class: 'GitSCM', branches: [[name: '*/master']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[url: 'https://github.com/akannan1087/myPythonDockerRepo']]])
            }
        }
       
        stage ('Build docker image') {
            steps {
                script {
                dockerImage = docker.build registry
                }
            }
        }
       
         // Uploading Docker images into Docker Hub
    stage('Upload Image') {
     steps{   
         script {
            docker.withRegistry( '', registryCredential ) {
            dockerImage.push()
            }
        }
      }
    }
   
    stage ('K8S Deploy') {
        steps {
            script {
                kubernetesDeploy(
                    configs: 'k8s-deployment.yaml',
                    kubeconfigId: 'K8S',
                    enableConfigSubstitution: true
                    )           
               
            }
        }
    }
  
    }  
}

Step # 5 - Build the pipeline
Once you create the pipeline and changes values per your Docker user id and credentials ID, click on 

Step # 6 - Verify deployments to K8S

kubectl get pods


kubectl get deployments
kubectl get services

Steps # 7 - Access Python App in K8S cluster
Once build is successful, go to browser and enter master or worker node public ip address along with port number mentioned above
http://master_or_worker_node_public_ipaddress:port_no_from_above

You should see page like below:


Please watch the above steps in YouTube channel:

3 comments:

  1. Hi
    I followed the above steps. The pipeline built was successful but when I run kubectl get pods the status of the pods is ImagePullBackOff. Any suggestions to make the pods running/

    ReplyDelete
    Replies
    1. By default it will Search for latest Tag. So update below Step

      // Uploading Docker images into Docker Hub
      stage('Upload Image to Docker HUB') {
      steps {
      script {
      docker.withRegistry('', registryCredential) {
      dockerImage.push()
      dockerImage.push('latest')
      }
      }
      }
      }

      Delete
  2. This comment has been removed by the author.

    ReplyDelete

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