kubernetes-devops

CI/CD of Jakarta EE Applications with Kubernetes

This demo will show how to do continous integration (CI)/continous delivery (CD) of Java/Jakarta EE applications using Kubernetes. We will use Azure DevOps Pipelines for our demo but you could easily use Jenkins or any other DevOps tool.

Prerequisites

• You will need a GitHub account.
• You will need an Azure subscription. If you don't have one, you can get one for free for one year here.
• You need to have a Docker Hub account.
• You need to have an Azure DevOps Project. You can sign up for Azure DevOps for free here. Here are instructions on how to set up an Azure DevOps Project. Make sure you choose Git for source control.

Setup the Kubernetes Cluster

• You will first need to have a Kubernetes cluster configured. We used the Azure Kubernetes Service but you can use any Kubernetes capable platform such as Google or IBM Cloud.
• Go to the Azure portal. Hit Create a resource -> Containers -> Kubernetes Service. Create a new resource group named jakartaee-cafe-group-<your suffix> (the suffix could be your first name such as "reza"). Specify the cluster name as jakartaee-cafe-cluster-<your suffix> (the suffix could be your first name such as "reza"). Hit Review + create. Hit Create.

Setup Kubernetes Tooling

• You will now need to setup kubectl. Here are instructions on how to do that.

• Next you will install the Azure CLI. Here are instructions on how to do that.

• You will then connect kubectl to the Kubernetes cluster you created. To do so, run the following command:

  az aks get-credentials --resource-group jakartaee-cafe-group-`<your suffix>` --name jakartaee-cafe-cluster-`<your suffix>`
  

  If you get an error about an already existing resource, you may need to delete the ~/.kube directory.

Create Service Connections

• Clone this repository into your own GitHub account. Make sure to update the kubernetes-devops/jakartaee-cafe/jakartaee-cafe.yml file to replace occurrences of rezarahman with <Your Docker Hub ID> on GitHub.
• Go to Azure DevOps home.
• Select your project. Click on project settings -> Pipelines -> Service connections -> Create service connection -> GitHub. Select Azure Pipelines as the OAuth configuration. Click authorize. Provide a connection name. Click save.
• Select New service connection -> Docker Registry. Select Docker Hub as your registry type. Specify the connection name to be docker-hub-<Your Docker Hub ID>. Fill in your Docker ID, password and email. Click save.
• Select New service connection -> Kubernetes. Select Azure subscription as your authentication. Select the namespace to be default. Select the cluster to be jakartaee-cafe-cluster-<your suffix>. Specify the connection name to be jakartaee-cafe-cluster. Click save.

Create and Run the Pipeline

• Select pipelines. Click new -> new build pipeline. Select GitHub as source control. Select jakartaee-docker from your own repository. Select existing Azure Pipelines YAML file. Select /kubernetes-devops/jakartaee-cafe/azure-pipelines.yml as the path.

• In the YAML file, replace occurrences of rezarahman with <Your Docker Hub ID>. When done, hit save and hit run.

• When the job finishes running, the application will be deployed to Kubernetes.

• Get the External IP address of the Service, then the application will be accessible at http://<External IP Address>/jakartaee-cafe:

  kubectl get svc jakartaee-cafe --watch
  

  It may take a few minutes for the load balancer to be created. When the external IP changes over from pending to a valid IP, just hit Control-C to exit.