Kubernetes Use-Case

Akanksha Chhattri
3 min readMar 14, 2021

What is Kubernetes?

Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available.

It was originally designed by Google and is now maintained by the Cloud Native Computing Foundation. It aims to provide a “platform for automating deployment, scaling,

and operations of application containers across clusters of hosts”. It works with a range of container tools and runs containers in a cluster, often with images built using Docker.

Kubernetes originally interfaced with the Docker runtime through a “Dockershim”; however, the shim has since been deprecated in favor of directly interfacing with containers or another CRI-compliant runtime.

The name Kubernetes originates from Greek, meaning helmsman or pilot. Google open-sourced the Kubernetes project in 2014.

Kubernetes combines over 15 years of Google’s experience running production workloads at scale with best-of-breed ideas and practices from the community

Use Cases: — —

CASE STUDY: IBM

Challenge

IBM Cloud offers public, private, and hybrid cloud functionality across a diverse set of runtimes from its OpenWhisk-based function as a service (FaaS) offering, managed Kubernetes and containers, to Cloud Foundry platform as a service (PaaS). These runtimes are combined with the power of the company’s enterprise technologies, such as MQ and DB2, its modern artificial intelligence (AI) Watson, and data analytics services.

Users of IBM Cloud can exploit capabilities from more than 170 different cloud-native services in its catalog, including capabilities such as IBM’s Weather Company API and data services. In the later part of 2017, the IBM Cloud Container Registry team wanted to build out an image trust service.

Solution

The work on this new service culminated with its public availability in the IBM Cloud in February 2018. The image trust service, called Portieris, is fully based on the Cloud Native Computing Foundation (CNCF) open source project Notary, according to Michael Hough, a software developer with the IBM Cloud Container Registry team. Portier is is a Kubernetes admission controller for enforcing content trust. Users can create image security policies for each Kubernetes namespace, or at the cluster level, and enforce different levels of trust for different images. Portier is is a key part of IBM’s trust story, since it makes it possible for users to consume the company’s Notary offering from within their IKS clusters. The offering is that the Notary server runs in IBM’s cloud, and then Portieris runs inside the IKS cluster. This enables users to be able to have their IKS cluster verify that the image they’re loading containers from contains exactly what they expect it to, and Portieris is what allows an IKS cluster to apply that verification.

Impact

IBM’s intention in offering a managed Kubernetes container service and image registry is to provide a fully secure end-to-end platform for its enterprise customers. “Image signing is one key part of that offering, and our container registry team saw Notary as the de facto way to implement that capability in the current Docker and container ecosystem,” Hough says. The company had not been offering image signing before, and Notary is the tool it used to implement that capability. “We had a multi-tenant Docker Registry with private image hosting,” Hough says. “The Docker Registry uses hashes to ensure that image content is correct, and data is encrypted both in-flight and at rest. But it does not provide any guarantees of who pushed an image. We used Notary to enable users to sign images in their private registry namespaces if they so choose.”

***************************Thank You *****************************

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