Creating a kubernetes cluster in Azure Cloud using Terraform

This is tutorial provides a Terraform code to deploy Azure Kubernetes Service (AKS) cluster in azure Cloud. The Azure Kubernetes Service (AKS) is a fully managed Kubernetes service for deploying, managing, and scaling containerized applications on Azure.

Tools and platforms

• Azure: Microsoft Azure, often referred to as Azure, is a cloud computing service operated by Microsoft for application management via Microsoft-managed data centers. You can get started with 12 months of free cloud computing services and $200 Azure credit for 30 days.

• Terraform: is an open-source infrastructure as code software tool that enables you to safely and predictably create, change, and improve infrastructure.

• Kubernetes: Kubernetes, also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications.

Assumption And Prerequisites

• You have created an Azure account, with a subscription.
• You have the latest az installed in your device.
• You have the latest kubectl installed in your device.
• You have the latest terraform installed in your device.

Provision Azure resources with Terraform

1- Set up an Azure account

To gain access to the Microsoft Azure management portal, you must have an Azure subscription and a Microsoft account associated with that subscription. To sign up for an Azure subscription

1- On the Microsoft Azure page, log in with a Microsoft account.

2- Choose Free Trial and follow the instructions to create a new account. Alternatively, choose Purchase Options and then choose the agreement that suits your purpose.

When your account is set up successfully, the Subscriptions page of the Account Center appears.

2- Create a storage account for Terraform state file

You can link your Azure CLI to your account with:

az login

And you can list your accounts with:

az account list

Make a note now of your subscription id.

If you have more than one subscription, you can set your active subscription with az account set --subscription="SUBSCRIPTION_ID".

Also setup the subscription ID as environment variable to be used later by Terraform

export TF_VAR_tenant_id="SUBSCRIPTION_ID"

Then follow the instruction here to create Azure Storage account to Store Terraform state that will be used in provider.tf file.

3- Provisioning a cluster using Terraform

Create multi-layer terraform state It is best practice to split the terraform into multi-layer architecture depending on complexity of the application environment. The principle is based on dividing the infrastructure into logical layers and representing these layers in the form of separate directories. The deployment of an infrastructure will therefore no longer be done by running Terraform in a single directory, but in as many directories as there are layers.

As an example here, we will split terrafrom into two layers: 1- network and security layer 2- compute and storage layer

• First, verify that the Terraform tool has been installed correctly with:

terraform version

• Then, set the working directory to the first layer directory

cd azure_terraform/network_security

• Initialize tge Terraform code

terraform init

• Verify the formatting, and the code validity

terraform fmt
terraform validate

• Plan the terraform code and direct the output to a json file

terraform plan --var-file=dev.tfvars --out=dev_plan_outputs.json

• Apply the terraform code from the json file that was created with the command perfomed above

terraform apply "dev_plan_outputs.json"

For production environment use the same steps above and replace dev.tfvars by prod.tfvars, dev_plan_outputs.json by prod_plan_outputs.json

• Switch back to the second layer directory (compute_storage) and perform the above steps again to initiate, plan and deploy the second layer infrastructure.

4- Terraform Deployment log:

• Terraform Apply

  first layer terraform apply log

  second layer terraform apply log

• The AKS cluster in Azure portal