Kubernetes Pod Vs Node

Kubernetes is an open-source container orchestration platform. Nodes, pods, and containers are the core components of the Kubernetes cluster. When it comes to Kubernetes pods and nodes, the terminologies may cause a little confusion for beginners.

This blog compares a Kubernetes pod with a node based on its role, working, control, abstraction, and many other aspects. It will help you completely understand the differences between the two components.

Let’s compare!

Table of Contents:

• What is a Kubernetes Pod?
• What is a Kubernetes Node?
• Kubernetes Vs and Node: Key Differences
• Summary of the differences
• Key Takeaways
• FAQs

What is Kubernetes Pod?

Let’s start with learning about a Kubernetes pod in this section.

Know that pods are the smallest deployable units in the Kubernetes platform. When you deploy applications in Kubernetes, you must create pods first. After that, you will add containers to the pods. A Kubernetes pod can have one or more containers. The containers can be Docker, Podman, or any other.

Every Kubernetes pod encapsulates key resources such as storage, container images, or networks in addition to containers. The main thing is that each container in the pod can use the same resources simultaneously. Additionally, containers in a pod communicate with each other.

Nonetheless, Kubernetes pods have a short lifetime in nodes. This is because pods are removed once their requirement is over.

Okay! Then, what is a Kubernetes node? The coming section will answer you.

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What is Kubernetes Node?

Let’s take a close look at a Kubernetes node.

A Kubernetes Node is typically the smallest computer hardware unit in the Kubernetes platform. Nodes contain storage and servers. When it comes to servers, they can be virtual machines or on-premises servers.

Every node in a Kubernetes cluster contains a group of pods. Moreover, every node holds resources like container runtime and Kubelet. Here, Kubelet enables communication between a Kubernetes node and the control plane. The container runtime helps to pull container images from a registry, unpack containers, and run container applications.

The nodes are usually managed by the control plane - the master worker node. The remaining nodes are known as worker nodes. The master node helps to schedule pods across the nodes in a Kubernetes cluster.

 Well! You have some insights into Kubernetes nodes and pods. It’s time to learn the differences between the two.

Kubernetes Pod Vs and Node: Key differences

In this section, let's compare the Kubernetes pod and node based on various parameters.

Role of the components:

A Kubernetes node is a Kubernetes cluster's smallest computer hardware unit. More to the point, it is the backbone of a Kubernetes cluster. Nodes are usually located inside clusters.

On the other hand, a Kubernetes pod is the smallest executable unit in a cluster. Pods are located inside nodes. They are the building blocks of a cluster. Every pod houses one or more containers. Similarly, every container holds applications and their dependencies.

Nature of the Components

A Kubernetes node is not dynamic as a Pod. If any node fails, the master node comes into the scene. It either restarts the node or shifts the pods of the node to another.

On the contrary, a Kubernetes pod is a dynamic powerhouse. Depending on the project or business requirements, you can scale up and down pods inside a node.

Internal Architecture

Kubernetes nodes have essential resources for their smooth run. To be precise, nodes have container runtime and Kubelet. The Kubelet acts as the primary node agent that helps to supervise nodes. The container runtime helps to pull containers from repositories and manage the containers.

On the other side, Kubernetes pods hold one or more containers. Every pod has its own IP address, storage, and configuration. The significant thing is that each container serves a unique goal. Containers share the same resources and local network. That’s why communication among containers is made easy. Above all, containers are tightly coupled.

Control Mechanism:

The master node or the control plane controls nodes in a Kubernetes cluster. Kubectl - the CLI interface - helps communicate with the control plane. Kubernetes API plays a crucial role in the communication.

On the flip side, a Kubernetes pod has a configuration file that supports running containers smoothly.

Types of the components

Kubernetes Pods have different types, such as single-container pods, multi-container pods, and init containers.

• Single container pods house only a single container.
• Init containers are the special containers that support initializing tasks inside a pod.
• Multiple containers in-house many containers.

On the other hand, Kubernetes nodes have different types, such as worker nodes, spot nodes, control plane nodes, and dedicated nodes.

• The master node controls other nodes and manages scheduling, monitoring, and scaling worker nodes.
• Worker nodes run pods based on workloads.
• Spot nodes are the cost-effective nodes that use cloud computing capabilities.
• Dedicated nodes are the special nodes used for running mission-critical applications.

Abstraction

Kubernetes pods are the abstractions of executable codes or containers, whereas Kubernetes nodes are the abstractions of computer hardware.

Working

If there is a change in the workload, Kubernetes scales up and down the number of pods in a node to balance the workload. When the Kubernetes cluster performs a specific process, pods will be active until the process is over.

On the flip side, you can use Kubectl – a command line interface – to create node objects. Once a Kubernetes node is created, the control plane checks the node's health first. If the node is not in good condition, the control plane creates pods in another node.

User Access

Generally, users cannot access Kubernetes nodes. They can access them only when maintenance is required.

On the other hand, users can access Kubernetes pods directly through IP addresses.

Cheers! Hope you have a better understanding of the difference between Kubernetes nodes and pods right now.

Summary of the Differences:

Let’s summarize the differences between Kubernetes nodes and pods in the Table below.

Key Takeaways:

• The number of containers in a pod and pods in a node must be less for maximum efficiency.
• Pods are typically the smallest execution unit in a Kubernetes cluster. Similarly, a node is the smallest hardware execution unit in a Kubernetes cluster.
• Every Kubernetes node has an agent, known as Kubelet, that enables communication with other nodes. Pods have one or more containers. Pods are the dynamic components of a cluster.
• Every container has applications, libraries, and binaries.

FAQs:

Is Kubernetes difficult to learn?

No, but at the same time, the learning curve of Kubernetes is steep for beginners. However, learning Kubernetes is not a great deal if you have sheer focus and determination to make a bright career. In MindMajix, we conduct Kubernetes training with industry-experienced trainers who will make your learning journey smooth and fun. Undoubtedly, you will step out as a master of Kubernetes because of our stellar training.

What is the difference between cluster and node in Kubernetes?

Kubernetes cluster is an environment that holds nodes and pods. A cluster has the necessary resources to manage the nodes. On the flip side, Kubernetes nodes contain pods where containers reside. Containers hold applications and other dependencies.

Can a pod run with a single container?

Yes, every Kubernetes pod can run with a single container. Moreover, a pod is highly efficient when it runs with a single container.

Can I run a Docker container in a Kubernetes pod?

Of course! You can run a Docker container in a Kubernetes pod seamlessly. Docker and Kubernetes can establish an ecosystem that supports efficient application development, deployment, and management.

How many Docker containers can I run in Kubernetes?

Clusters in Kubernetes v1.29 support up to 5,000 nodes and 300,000 containers. It also supports up to 110 pods per node and 150000 total pods.

Conclusion

In short, a Kubernetes node encapsulates one or more pods, whereas a pod encapsulates one or more containers. Pods act as dynamic containers that have applications and their dependencies. On the other hand, nodes act as reliable hosts for pods. Well! This blog might have helped you distinguish between the Kubernetes node and pod terminologies.

If you want to explore Kubernetes pods and nodes more, you can check out a Kubernetes training in MindMajix. It will help you to acquire in-depth knowledge of Kubernetes pods and nodes in a significant way. Eventually, it will help you elevate your career in DevOps to new heights.