devops

CI/CD for Jakarta EE Applications with Kubernetes

This demo will show how to do continous integration (CI)/continous delivery (CD) of Jakarta EE applications using Kubernetes. We will use GitHub Actions 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.

Start Managed PostgreSQL on Azure

We will be using the fully managed PostgreSQL offering in Azure for this demo. If you have not set it up yet, please do so now.

• Go to the Azure portal.
• Select 'Create a resource'. In the search box, enter and select 'Azure Database for PostgreSQL'. Hit create. Select a single server.
• Specify the Server name to be jakartaee-cafe-db-<your suffix> (the suffix could be your first name such as "reza"). Create a new resource group named jakartaee-cafe-group-<your suffix> (the suffix could be your first name such as "reza"). Specify the login name to be postgres. Specify the password to be Secret123!. Hit 'Create'. It will take a moment for the database to deploy and be ready for use.
• In the portal, go to 'All resources'. Find and click on jakartaee-cafe-db-<your suffix>. Open the connection security panel. Enable access to Azure services, disable SSL connection enforcement and then hit Save.

Once you are done exploring the demo, you should delete the jakartaee-cafe-group-<your suffix> resource group. You can do this by going to the portal, going to resource groups, finding and clicking on jakartaee-cafe-group-<your suffix> and hitting delete. This is especially important if you are not using a free subscription! If you do keep these resources around (for example to begin your own prototype), you should in the least use your own passwords and make the corresponding changes in the demo code.

Setup the Kubernetes Cluster

• You will need to have a Kubernetes cluster configured. We used the Azure Kubernetes Service but you can use any Kubernetes capable platform.
• Go to the Azure portal. Hit Create a resource -> Containers -> Kubernetes Service. Select the resource group to be 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.

• Please delete the ~/.kube directory for good measure.

• 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.

Set Up GitHub Actions Access

• Clone this repository into your own GitHub account.

• Go to the Azure portal. Go to the subscription you are using. Note down the subscription ID.

• Create a new Azure service principal by executing the following command:

  az ad sp create-for-rbac --name "jakartaee-cafe-principal" --role contributor --scopes /subscriptions/<your subscription ID>/resourceGroups/jakartaee-cafe-group-<your suffix> --sdk-auth
  

• Copy and save aside the JSON object for your service principal:

  {
      "clientId": "<GUID>",
      "clientSecret": "<GUID>",
      "subscriptionId": "<GUID>",
      "tenantId": "<GUID>",
      (...)
  }  

• Go to Settings -> Secrets on your GitHub repository.

• Click 'New repository secret'. Specify the secret name to be 'AZURE_CREDENTIALS'. The Value will be the service principal JSON from above.

• Click 'New repository secret'. Specify the secret name to be 'DOCKERHUB_USERNAME'. The Value will be your Docker Hub username.

• Click 'New repository secret'. Specify the secret name to be 'DOCKERHUB_PASSWORD'. The Value will be your Docker Hub password.

Run GitHub Actions Workflow

• Make sure to update the devops/jakartaee-cafe.yml file to replace occurrences of rezarahman with <Your Docker Hub ID> and occurrences of reza with <your suffix> on GitHub.

• Similarly, make sure to update the .github/workflows/main.yml file to replace occurrences of reza with <your suffix> on GitHub.

• Go to Actions -> Workflows -> All workflows -> Main Build -> Run workflow -> Run workflow.

• 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.