What is Kubelet in Kubernetes?

Last Updated : 21 May, 2024

A Kubelet in Kubernetes is a crucial component of the primary node agent that runs on each node. It assists with container management and orchestration within a Kubernetes cluster. Kubelet supports communication between the Kubernetes control plane and individual nodes and it also enables the efficient deployment and execution of containerized applications across the cluster.

What is Kubelet in Kubernetes?

Kubelet is an essential component of the Kubernetes framework, controlling and coordinating pods and nodes. Its features include pod deployment, resource management, and health monitoring, all of which significantly improve the operational stability of a Kubernetes cluster. It registers the node with the apiserver using the hostname, an override flag, or specific logic for a cloud provider. The kubelet operates by the PodSpec, which is a YAML or JSON object that defines a pod.

Why is Kubelet is Important?

Kubernetes Kubelet helped IT teams connect their K8s with other APIs. In recent years, the craze has turned toward virtual Kubelet. A virtual Kubelet, like a Kubernetes Kubelet, enables K8s to communicate with other APIs. The difference is that the virtual Kubelet is an open-source version of the traditional Kubelet.

Use Cases of Kubelet

Below are some use cases of kubelet

Cloud-Native Development: Kubelet helps Dev and Ops teams to develop native applications efficiently. Kubelet serves as an enabler, enabling them to do so without having to worry about security or other issues when more and more enterprises want to provide their developers with direct access to their Kubernetes environment.
Better CI/CD & Testing: Kubelet achieves Continuous Integration and Delivery. DevOps requires full-day access to containers for effective CI/CD implementation and testing, particularly in the Kubernetes environment.

Kubelet Key Concepts

Node administration: Node's responsibilities include acquiring resources and network configuration to overall operational efficiency. Notably, Kubelet bridges the communication gap between worker nodes and the main node, resulting in a coherent network that ensures the cluster's operational stability.
Pod execution: A pod is Kubernetes' smallest deployable unit, containing one or more containers. A pod encloses one or more containers, serving as an operational. The orchestration of these pods requires constant attention.

Kubelet Architecture

Components: It serves a specific function crucial to the orchestration framework. The Kubelet Agent acts as a mediator, allowing the exchange of commands and information between the node and the Kubernetes control plane.
Control Plane Interaction: Kubelet's architecture is distinguished by strong interaction with the Kubernetes control plane. This communication channel allows the sharing of crucial information required for the cluster.

Benefits of Kubelet in Kubernetes

Below are some benefits of Kubelet in Kubernetes

Kubelet often allows you to connect to various services from cloud providers in different regions.
You only pay for the resources you use with this, and enable DevOps engineers to pay only for the resources they use.
A Kubelet provides enhanced portability to connect Kubelet to your managed service from anywhere in the world.
Engineers can use Kubelet to get access to services that are only available in a certain location.

Conclusion

The Kubelet operates the deployment of pods to Kubernetes nodes. It receives commands from the API server and informs the container runtime to start and stop containers as needed.