Updated April 13, 2023
Introduction to Kubernetes Federation
Kubernetes federation is defined as, it is a tool which is used for synchronization in the configuration of various cluster in Kubernetes which is referred to as KubeFed that support a new standard that has the commonly used components in Kubernetes, and we can control the cluster which is all from the set of APIs in the hosting cluster in such a way that which cluster will control, and we can also able to control the look of configuration, and it provides lower-grade tools so that can be used as a basis for progressively compound Kubernetes with its use cases over various clusters.
What is Kubernetes federation?
The Kubernetes federation or KubeFed is a tool which is used for synchronization in the configuration of various clusters, the Kubefed can manage which cluster we need to define or not and also can manage what configuration will look like, it allows a low-level mechanism that can be used to increase the production in Kubernetes, the federation can also be useful for calibration it means it calibrate the application over all the various data center in which the applications in the place to support the local variables with each member of the cluster, we can put up special things from the domain name and network policies which are different from the environment, the Kubefed can use the two types of configurations that are type configuration, in which it defines the type of API which can be handled by the KubeFed and another is cluster configuration in which it defines the cluster which can be selected by KubeFed.
How to setup Kubernetes federation?
To set up the Kubernetes federation there are some steps that we need to follow,
Step1: To install Kube federation on the host cluster-
Previous to start working with multiple clusters we have to install the Kube federation tool on the host cluster control plane by executing the command as given below,
“helm –namespace kube-federation-system upgrade -i kubefed kubefed-charts/kubefed –create-namespace –kube-context cluster1”
Step 2: To join cluster into a federation-
For joining the cluster we need to have context for that we have to run the below command,
“kubectl config get-contexts”
We can generate the federation cluster by using two clusters such as Admin@cluster1 and Admin@cluster2 in which cluster 1 will be the host and the kubefedctl tool has been utilized to unite the clusters,
“kubefedctl join cluster1–cluster-context Admin@cluster1 –host-cluster-context Admin@Cluster1”
“kubefedctl join cluster2–cluster-context Admin@cluster2 –host-cluster-context Admin@Cluster1”
Step 3: To test clusters have successfully joined-
We can inspect both the clusters are managed in the federation
“kubectl -n Kube-federation-system get kubefedclusters”
Step 4: Creating a federal namespace-
To generate the federated namespace on the host cluster is very important because we can place the kubernetes assets to this namespace o make it available for various clusters, we can use the YAML configuration for generating the federated namespace.
Step 5: To develop an application to all clusters in the federation-
The deployment of an application will work similarly for service objects, we need to deploy the YAML configuration which has the federated namespace so that it will be developed automatically for both clusters in the federation.
Architecture of Kubernetes federation
The host cluster is the fundamental abstraction for supporting the Kubernetes federation, the host cluster carries any configuration that will generate the members of the cluster, it is a member which can run the real workloads also but generally, any organization will have the host cluster as a standalone cluster for clarity.
One API can manage the entire configuration all over the cluster in which a configuration can decide which cluster should be applied and what they will do, it has a set of policies, templates, and it can set aside the specific cluster to individual cluster which can control the configuration of the federation and also the configuration of the federation can control the DNS entries for all the multi-cluster services, it has ruled for creating the configuration to get access to any cluster which can be applied or removed which has in the development that usually have their own namespaces that remain compatible over the cluster.
How to Create Kubernetes federation?
The Kubernetes federation can be created at the host cluster which has clusters members in which the host cluster can be a member and it runs real workloads also but generally the host cluster is the independent cluster that provides the clarity.
The development of the federation control plane is very similar to the development of the long-established in which it provides similar functionality, to creating them in the federation control plane that makes sure that the inclination number of replicas exist over all the registered cluster.
We can create a federated deployment by sending a request to the federation apiserver, we can run the command for it such as,
“kubectl –context=federation-cluster create -f mydevelopment.yaml”,
Where the ‘–context=federation-cluster’ will use to submit the request to the federation API server instead of it sending to the kubernetes cluster.
When the federated deployment has been created then the control plane will generate the deployment in all kubernetes clusters, we can check the cluster by executing the command below,
“kubectl –context=fdh-bdup-west1a get deployment mydep”, so we can say that the cluster with the name ‘fdh-bdup-west1a’ has been created.
Example Kubernetes federation
In this example, we have seen that how the configurations are propagated over all the clusters,
apiVersion: types.kubefed.io/v1beta1 kind: FederatedDevelopment metadata: name: myinx-test namespace: myinx-test spec: guide: metadata: labels: app: myinx spec: replicas: 4 selector: matchLabels: app: myinx guide: metadata: labels: app: myinx spec: containers: - image: myinx name: myinx placement: clusters: - name: cluster1 - name: cluster3
In this article we conclude that the Kubernetes federation tool can be used for synchronization in the cluster of kubernetes, so we have also seen the setup, architecture, and how to create the federation of kubernetes, so if anyone wants to understand the concept of federation then this article will helpful.
We hope that this EDUCBA information on “Kubernetes Federation” was beneficial to you. You can view EDUCBA’s recommended articles for more information.