Kubernetes today is a hugely prevalent tool in 2021, and more organizations are increasingly running their applications on multiple clusters of Kubernetes. But these multiple cluster architectures often have a combination of multiple cloud providers, multiple data centers, multiple regions, and multiple zones where the applications are running. So, deploying your application or service on clusters with such diverse resources is a complicated endeavor. This challenge is what the process of a federation is intended to help overcome. The fundamental use case of a federation is to scale applications on multiple clusters with ease. The process negates the need to perform the deployment step more than once. Instead, you perform one deployment, and the application is deployed on multiple clusters as listed in the federation list.

What Is Kubernetes Cluster Federation?

Essentially, the Kubernetes cluster federation is a mechanism to provide one way or one practice to distribute applications and services to multiple clusters. One of the most important things to note is that federation is not about cluster management, federation is about application management.

Cluster federation is a way of federating your existing clusters as one single curated cluster. So, if you are leveraging Kubernetes clusters in different zones in different countries, you can treat all of them as a single cluster.

In cluster federation, we optimize a host cluster and multiple-member clusters. The host cluster comprises all the configurations which pass on all the member clusters. Member clusters are the clusters that share the workloads. It is possible to have a host cluster also share the workload and act as a member cluster, but organizations tend to keep the host clusters separate for simplicity. On the host cluster, it’s important to install the cluster registry and the federated API. Now with the cluster registry, the host will have all the information to connect to the member Clusters. And with the federated API, you require all the controllers running on our host clusters to make sure they reconcile the federated resources. In a nutshell, the host cluster will act as a control plane and propagate and push configuration to the member clusters.

#kubernetes #cluster #cluster management #federation #federation techniques #cluster communication