Fix for Kubernetes Deployment Error using helm chart | Error: kubernetes cluster unreachable: exec plugin: invalid apiversion "client.authentication.k8s.io/v1alpha1"

 Error: kubernetes cluster unreachable: exec plugin: invalid apiversion "client.authentication.k8s.io/v1alpha1"

 

Root cause and fix:

Downgrading helm version to 3.8.2 would resolve the issue.

curl -L https://git.io/get_helm.sh | bash -s -- --version v3.8.2

How to Deploy Springboot Microservices App into EKS cluster using Jenkins Pipeline and Helm | Deploy Microservices into EKS cluster using Helm and Jenkins Pipeline

We are going to learn how to automate build and deployment of Springboot Microservices Docker Container into Elastic Kubernetes Cluster(EKS) using Helm and Jenkins pipeline.

What is Helm?

Helm is a package manager for Kubernetes. Helm is the K8s equivalent of yum or apt. It accomplishes the same goals as Linux system package managers like APT or YUM: managing the installation of applications and dependencies behind the scenes and hiding the complexity from the user.

To learn more about Helm, please click here.

Sample springboot App Code:

I have created a sample Springboot App setup in GitHub. Click here to access code base in GitHub. 

Jenkins pipeline will:

- Automate maven build(jar) using Jenkins
- Automate Docker image creation
- Automate Docker image upload into Elastic container registry(ECR)
- Automate Springboot docker container deployments into Elastic Kubernetes Cluster using Helm charts

Pre-requisites:

1. EKS cluster needs to be up running. Click here to learn how to create Amazon EKS cluster.

2. Jenkins instance is up and running

3. Install AWS CLI on Jenkins instance

4. Helm installed on Jenkins instance

5. Install 

6. Install eksctl on Jenkins instance

7. Install Docker in Jenkins and Jenkins have proper permission to perform Docker builds

8. Make sure to Install Docker, Docker pipeline 

9. Create ECR repo in AWS

10. Dockerfile created along with the application source code for springboot App.

11. Namespace created in EKS cluster

The Code for this video is here:

Make sure you fork my repo https://github.com/akannan1087/docker-spring-boot

Create Helm chart using helm command

Go to your root of repo where you have source code for your springboot application. Create helm chart by executing below command:

helm create mychart

tree mychart

Execute the above command to see the files created.

Add Docker image details to download from ECR before deploying to EKS cluster

open mychart/values.yaml.

Enter service type as LoadBalancer

And also

open mychart/templates/deployment.yaml and change containerPort to 8080

Save the files, commit and push into repo.

Step # 1 - Create Maven3 variable under Global tool configuration in Jenkins

Make sure you create Maven3 variable under Global tool configuration. 

Step #2 - Create Credentials for connecting to EKS cluster using Kubeconfig

Go to Jenkins UI, click on Credentials -->

Click on Global credentials

Click on Add Credentials

use secret file from drop down.

you should see the nodes running in EKS cluster.

kubectl get nodes

Execute the below command to get kubeconfig info, copy the entire content of the file:

cat ~/.kube/config

Open your text editor or notepad, copy and paste the entire content and save in a file.

We will upload this file.

Enter ID as K8S and choose File and upload the file and save.

Step # 3 - Create a namespace in EKS

kubectl create ns helm-deployment

Step # 4 - Create a pipeline in Jenkins

Create a new pipeline job.

Step # 5 - Copy the pipeline code from below
Make sure you change below red marked values as per your settings highlighted in yellow below:

pipeline {

   tools {

        maven 'Maven3'

    }

    agent any

    environment {

        registry = "account_id.dkr.ecr.us-east-1.amazonaws.com/my-docker-repo"

    }

   

    stages {

        stage('Cloning Git') {

            steps {

                checkout([$class: 'GitSCM', branches: [[name: '*/master']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: '', url: 'https://github.com/akannan1087/docker-spring-boot']]])     

            }

        }

      stage ('Build') {

          steps {

            sh 'mvn clean install'           

            }

      }

    // Building Docker images

    stage('Building image') {

      steps{

        script {

          dockerImage = docker.build registry 

          dockerImage.tag("$BUILD_NUMBER")

        }

      }

    }

   

    // Uploading Docker images into AWS ECR

    stage('Pushing to ECR') {

     steps{  

         script {

                sh 'aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin account_id.dkr.ecr.us-east-1.amazonaws.com'

                sh 'docker push account_id.dkr.ecr.us-east-1.amazonaws.com/my-docker-repo:$BUILD_NUMBER'

         }

        }

      }

        stage ('Helm Deploy') {

          steps {

            script {

                sh "helm upgrade first --install mychart --namespace helm-deployment --set image.tag=$BUILD_NUMBER"

                }

            }

        }

    }

}

Step # 6 - Build the pipeline

Step # 7 - Verify deployments in EKS

Execute the below command to list the helm deployments:

helm ls -n helm-deployment

kubectl get pods -n helm-deployment

kubectl get services -n helm-deployment

Steps # 8 - Access Springboot App Deployed in EKS cluster

Once deployment is successful, go to browser and enter above load balancer URL mentioned above

You should see page like below:

Cleanup EKS Cluster using eksctl

To avoid charges from AWS, you should clean up resources. 

eksctl delete cluster --name demo-eks --region us-east-1

Watch steps in Youtube channel:

How to Deploy Springboot Microservices into AKS cluster using Helm and Azure Pipelines | Deploy Docker Containers into AKS cluster using Azure Pipelines | Deploy Microservices into AKS cluster using Helm and Azure Pipelines

We are going to learn how to deploy Springboot Microservices Docker container into Azure Kubernetes Cluster(AKS) using Helm and Azure pipelines. 

Sample springboot App Code:

I have created a sample Springboot App setup in GitHub. Click here to access code base in GitHub.

Watch steps in YouTube channel:

What is Helm?

Helm is a package manager for Kubernetes. Helm is the K8s equivalent of yum or apt. It accomplishes the same goals as Linux system package managers like APT or YUM: managing the installation of applications and dependencies behind the scenes and hiding the complexity from the user.

Helm Charts

Helm uses a packaging format called Charts. A Helm Chart is a collection of files that describe a set of Kubernetes resources. Helm Charts helps you define, install, and upgrade even the most complex Kubernetes application. Charts are easy to create, version, share, and publish.

Implementation steps:

1. Create a resource group, AKS cluster and Azure container registry 
2. Provide pull access for AKS to pull image from ACR 
3. Create a namespace for helm deployment
4. Create a helm chart for spring boot app
5. Create a build pipeline to automate docker image
6. Customize pipeline with helm package tasks
7. Create a release pipeline
8. Customize pipeline with helm upgrade tasks 
9. Run the pipeline to deploy springboot app into AKS
10. Verify deployments in the namespace in AKS
11. Use kubectl port forward to access app locally
12. Access the app in the browser

Pre-requisites:

• Azure CLI is installed on your local machine.
• Helm installed
• kubectl installed
• Azure subscription, click here if you don't have one.
• AKS cluster needs to be up running. You can create AKS cluster, ACR Repo using shell script provided in my website.
• Azure DevOps project dashboard in https://dev.azure.com/
• Dockerfile created along with the application source code for springboot App.
• Make sure AKS has pull access from ACR

Create Helm chart using helm

helm create mychart

tree mychart

Execute the above command to see the files created.

Add Docker image details to download from ACR before deploying to AKS cluster

open mychart/values.yaml

image:

repository: myacrrepo531.azurecr.io/akannan1087/docker-spring-boot

tag: ""

open mychart/templates/deployment.yaml and change containerPort to 8080

Save the files into SCM you are using.

Make sure worker nodes are running

kubectl get nodes

Pipeline Implementation Steps:

Part 1 - Create Azure Build pipeline for building Docker image, uploading image into ACR and packaging helm chart.

Part 2 - Create Azure Release pipeline for deploying Springboot Docker containers into AKS using helm upgrade task.

 

Part 1 - How to create a Azure Build Pipeline

1. Login into your Azure DevOps dashboard

2. Click on Pipelines.

3. Click on New Pipeline

4. Click on use the classic editor

Enter your repo name and branch name where you have stored your source code along with Dockerfile:

Click on Continue. Now choose the template by typing Helm, Select Azure Kubernetes service and click Apply.

Now pipeline is created with six tasks already. We need to start customizing the pipeline:

Select Ubuntu as build agent from Agent specification drop down, avoid Windows server as build agent.

Let's also add Maven build task for building the JAR file.

Click on + icon and type Maven. this should be the first task.

And then enter maven goal as package

Let's modify Build an image task.

Select Push an image task

Leave Install Helm Task as it is, we need that task to install Helm on build agent

Remove helm init task by selecting remove selected task

Customize helm package task, select Chart Path by clicking ... dots

Choose the folder where you have helm chart files, select OK

Leave Publish artifact task as it is.

Now click Save + Queue and run to start Building the pipeline

Check build output..

Once the build is completed, you should be able to see the Docker image in Azure Portal under Resource Group, ACR repo name --> Repositories

Part 2  - How to Create Release pipeline for deploying Springboot Microservices containers into AKS Cluster

Go to Pipelines --> Click on Releases --> New Release pipeline

Click on Stage 1 and choose a template by typing helm

and choose Deploy an application to K8S cluster using helm chart

Change the stage name to Deploy to AKS

Now click on Add an artifact

Select the Build pipeline and click on the latest version

Now click on Deploy to AKS stage

Click on Deploy to AKS 

Enter right value for Azure subscription, Resource group and AKS Cluster by selecting from down down.

Now click on the Agent Job, and select Azure pipelines and choose Ubutu as Build agent, avoid windows agents.

Leave install Helm 2.9.1 task

make sure check for latest version of Helm. this will install latest version of Helm which is 3.x

Remove helm init task by selecting remove selected task

Let's start customizing helm upgrade task. Enter helm-deployment as namespace, chart type as File path and click on three dots.

choose the package mychart-0.1.0.tgz and click ok.

Enter first as release name

enter below values for for set values:

image.tag=$(Build.BuildId)

Now click on Save.

Optional step - Enable Continuous Deploy Trigger

This will deploy microservices into AKS cluster for every new build in build pipeline.

Click on Create a release

and then click Create 

Click on Release number to see the output

Click on Stage to see the logs

Click on Logs, you will see the following tasks are in green to confirm Deployment was successful.

Let's check if deployment created any pods in helm-deployment namespace.

How to access Springboot Application using port forward locally?

kubectl get deployments -n helm-deployment 

kubectl get pods -n helm-deployment 

Get the pod name and use port forward to access locally

kubectl port-forward first-springboot-pod_name 8080 -n helm-deployment

If you see any errors after deploying the pods, you can check the pod logs.

kubectl describe pod <pod_name>  -n helm-deployment 

Go to the browser enter http://localhost:8080

You should see below web page.

Clean up Resources

Let us see how to clean up the resources that were created. We can use az group delete command to remove the resource group, AKS cluster, and all related resources. 

az group delete --name aks-rg --yes --no-wait