Why Certifying Kubernetes Clusters is Important?

This is 2022. A large number of organizations have moved to the cloud to host their digital services and applications. Not just this, they have surely adopted cloud-native architecture and technology or have taken extensive steps to increase agility in service delivery using it. Kubernetes is the most used cloud-native open-source tool and it is at the stage of becoming a ‘Linux’ of cloud-native infrastructure.

Initially, Kubernetes has been used with a single cluster where nodes and pods are deployed in one type of environment. Over time, with a need to optimize CAPEX and tap global expansion opportunities, organizations started using multi-cloud where different types of Kubernetes distributions can be used. It can be a managed platform hosted by one of the big 3 public clouds like Amazon EKS, Azure AKS, and Google’s GKE or unmanaged offerings from cloud solution vendors deployed on a private cloud.

Such a multi-vendor model is complicated for any organization to manage. Especially, from a Day 2 management perspective, when you need to do housekeeping of the overall infrastructure and applications to ensure faster time-to-market without any hassle.

There are some implications when it comes down to managing multiple clusters. These are mentioned below

Distributed clusters hosted in a diversified cloud environment.

Different cloud environments have different configuration mechanisms, API integrations, network connectivity, and policies to interchange information from other environments. Also, different Kubernetes cluster versions as well.

Different cloud-native tools are deployed across clusters.

There are a plethora of tools available in the cloud-native landscape, and most deployments are leveraging these tools for different purposes in clusters. For example, tools are available for monitoring, internetworking, security, compliance, scheduling, container registry, chaos engineering, etc. Each of these deployed tools in the cluster may need regular upgrades to newer versions after a specific period. This results in an overall upgrade of clusters to keep up with compatibility with the K8s cluster version and other tools and underlying applications.

Application components are distributed across clusters

Not just the cluster and other tools deployed, but the applications also get upgrades and some point of time termination. Applications have a lifecycle that needs to be taken care of while deployed in a distributed manner.

Infrastructure and application compatibility

All of these issues come to the point where we need to ensure the compatibility between the infrastructure or cluster and underlying applications in any operation we do in the Day 2 phase of your cloud-native infrastructure. While performing any task in the lifecycle management of applications or clusters or cluster-hosted tools, you need to check if all components are working together perfectly before moving to production.

Assuring the cluster and applications readiness

Now the question is, how should we assure the compatibility of clusters and applications in their lifecycle?

There are 3 aspects to checking the performance of both clusters and applications.

1.     Perform different test cases when adding a new cluster. You need to perform tests like health checks, resiliency, CIS security, API security, pod robustness, and E2E conformance on your clusters. We should be able to build and run custom test cases to check additional parameters. This is to ensure that the newly added cluster is good to go running any applications on it in production.

2.     Perform scans or tests of applications before onboarding them to clusters. There should be a provision for a system to simply read out the application properties and identify if this application package is a good way to be onboarded on the clusters. It must have certain features and meet certain criteria before it can be onboarded in the clusters. The possibility of disturbing the other applications will be decreased with this approach.

3.     Performing certification when clusters and applications are onboarded. It can be similar to the above, but test cases should run when clusters and applications are up and running. In this case, recertification of new features of the new Kubernetes version needs to be done to validate that performance and interoperable and better capabilities. This type of recertification is important as it ensures a new upgrade to the cluster that has not impacted the existing performance of the platform and infrastructure and it is perfectly fine with existing applications. It should not happen that old features are simply dropped without being notified. If that happens, the applications that were using the old features of the platform will be dead and it will be impossible to identify the cause of the issues. If this is happening without being notified, it will have an impact on the system.

Summarizing, implementing Kubernetes is easy in a single environment where you can perform interoperability and performance test between clusters and applications in case of upgrades. It is never easy when different and multiple-distributed clusters are involved in the IT environment. In the production environment, IT teams always need to make sure services run smoothly in any circumstance along with optimal performance. Our product CloudCompass is helpful for any multicloud/ edgecloud environment where Kubernetes is implemented.