AKS Addons, Part I: Storage

• Using Kubernetes’ extensibility interfaces, Azure Kubernetes Service (AKS) can support a variety of Azure storage services.
• Access to storage services enables stateful applications in AKS that can retain data from one invocation to the next

When Kubernetes was first launched by Google in 2015, it natively supported only stateless application containers, that is, containers had no memory (“state”) of invocations from one request to the next. This meant that Kubernetes-based applications could not remember, for example, user identity across HTTP requests. 

However, the Kubernetes infrastructure was designed to support extensibility, and hundreds of such extensions—for storage, network, and device support—have appeared, most under the sponsorship of the Cloud Native Computing Foundation (CNCF). (For details, see the sidebars “Azure, Kubernetes, and the CNCF” and “Understanding Kubernetes Extensibility”.) These extensions can provide access to a broad range of storage services based on the needs of the specific application.