Azure Kubernetes Service (AKS) Environment Variables

Azure Kubernetes Service (AKS) is a managed container orchestration service that simplifies deploying, managing, and scaling containerized applications using Kubernetes. Before diving into the essential environment variables, it’s important to understand how AKS works.

How AKS Works

AKS manages the Kubernetes control plane, allowing you to focus on your application workloads. Here’s a simplified workflow of how AKS operates:

1. Cluster Creation: When you create an AKS cluster, Azure automatically sets up the Kubernetes control plane across multiple Azure availability zones to ensure high availability.
2. Node Pools: AKS uses node pools, which are groups of virtual machines (VMs) that run your containerized applications. You can scale node pools up or down based on the workload demands.
3. Deploying Applications: Applications are deployed as Kubernetes pods, which are the smallest deployable units in Kubernetes. Pods are hosted on the nodes in your cluster.
4. Monitoring and Scaling: AKS integrates with Azure Monitor, allowing you to track your cluster’s performance. It also supports auto-scaling based on metrics like CPU and memory usage.
5. Integration with Azure Services: AKS integrates seamlessly with other Azure services like Azure Active Directory for access control, Azure Container Registry for storing images, and more.

Essential AKS Environment Variables

Now, let’s focus on the core environment variables that are crucial in an AKS deployment:

1. KUBERNETES_SERVICE_HOST

• Provides the IP address of the Kubernetes API server, allowing applications to communicate with it.

Example:

KUBERNETES_SERVICE_HOST=10.0.0.1        

2. KUBERNETES_SERVICE_PORT

• The port on which the Kubernetes API server listens, typically set to 443 for HTTPS.

Example:

KUBERNETES_SERVICE_PORT=443        

3. NAMESPACE

• Specifies the Kubernetes namespace in which the application is running, helping to organize resources.

Example:

NAMESPACE=production        

4. POD_NAME

• The name of the pod in which the container is running, crucial for logging and debugging.

Example:

POD_NAME=my-app-pod-12345        

5. POD_NAMESPACE

• Holds the namespace of the current pod, specifically used for referring to the pod’s namespace.

Example:

POD_NAMESPACE=default        

Understanding how AKS works and the essential environment variables is crucial for managing your containerized applications. By mastering these key elements, you can ensure that your applications are configured correctly and are running efficiently on AKS.