While Docker is used for packaging the containerized applications on single node, Kubernetes runs them across a cluster. Docker can work with container schedules. Kubernetes can also work with other container types and runtimes.
In this article on Kubernetes vs Docker, we will discuss the differences between the two. We will also learn about the two platforms in detail in later sections.
Table of Contents
Kubernetes vs Docker: What is the difference?
Let us take a look at the differences between Kubernetes and Docker to understand which is more suitable for your application.
|Used for maintaining and deploying containers||Used for automating the deployment of applications in lightweight containers for efficient working of applications in different environments|
|Applications are deployed as the combination of pods, services and deployment||Apps are deployed in form of services|
|Supports auto-scaling of containers in a cluster||Does not support auto-scaling|
|Health checks are for liveness and readiness||Health checks are limited to service|
|Difficult set up and configuration||Easy setup and installation|
|Kubernetes swarm requires built-in monitoring||Docker swarm required third-party tools for monitoring|
|Used by companies such as Azure, Intel, Shopify, Buffer, Evernote||Used by companies such as Google, Citizens bank, ADP, Amazon, VISA, MetLife|
What is Kubernetes?
Kubernetes/K8s/Kube is a portable, extensible and an open source platform that is used for managing containerized workloads and services. In simple terms, it is a container orchestrator that ensures that each container is where it is supposed to be so that containers can work together.
It is an open source system that is used for managing containerized applications across multiple hosts. Google developed Kubernetes but currently, it is maintained by the Cloud Native Computing Foundation. Kubernetes automates manual processes such as scaling, software development and management. The aim is to ensure that services are running smoothly as per the requirement of the app developer.
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Why do app developers use Kubernetes?
To resolve the issues with the use of Monoliths, microservices were introduced. However, microservices had too much of a machine requirement due to which containers became popular in use. To manage these containers on virtual machines/nodes, Kubernetes was brought in use. It is useful for applications that have many containers. K8s manages containers in different deployment environments such as virtual and physical machines, and cloud environments.
Nodes within the containers that they run in, are grouped together as a ‘cluster’. Every container has DNS, storage, endpoints and scalability. Kubernetes is useful in automating most inefficiencies and repetition that may otherwise occur in manual processes. App developers inform Kubernetes about the way it wants the cluster to appear. Kubernetes ensures the same.
In summary, the following factors facilitated the use of this container orchestration tool:
- Transition from Monoliths to microservices
- Increased usage of containers in microservices
- For properly managing containers
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Features of Kubernetes
Following are the features of Kubernetes:
- No downtime: High availability leads to no downtime, which means the web application is always accessible to users.
- High performance: The application loads very fast, due to which users also have high response rates from the application.
- Backup: In case any data is lost or damage is caused to the system, Kubernetes can run in the later stages.
How Does Kubernetes Work?
In the Kubernetes architecture, there is a master node that is connected to multiple worker nodes. Every node has a Kubelet process running on it. Kubelet is a process in Kubernetes that allows different clusters to communicate with each other and execute tasks on nodes. Worker nodes have docker containers of various applications that are deployed on it.
Depending on the distribution of the workload, there will be different numbers of docker containers that will be running on worker nodes. The actual action is taking place at the worker node and the applications are running over them.
The master node runs all the necessary processes that are necessary to run and manage clusters properly, such as etcd, API server, controller manager, and scheduler. Master node runs all the necessary processes that are necessary to run and manage clusters properly such as API server that are the entry point to Kubernetes clusters
Virtual network enables the communication between master node and worker nodes thus turning all nodes into one powerful machine. Worker nodes have the most load since applications run on them and they contain many containers within them. However, the master node is the most important since losing it will make you lose access to the cluster. This is why in production, there are two masters within the cluster.
What is Docker?
Docker is a set of platform-as-a-service (PaaS) products. These products use OS-level virtualization for delivering software in the standardized units known as Containers. It is a platform that helps in building, testing, and deploying containers in a quick manner. The term ‘Docker’ can refer to two things. It can refer to commands and a daemon that are collectively called tools. They may also refer to the Dockerfile file format.
Why use docker?
It is very useful for those developers who require a lightweight and clean testing environment for testing without any complex orchestration. Developers can easily access native containerization capabilities through simple commands. They can also automate them using an application programming interface (API). Docker containers can be run on any operating system and cloud providers to build and deploy containerized applications with Docker.
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Features of Docker
Following are the features of Docker due to which developers use them:
- Faster Configuration: Docker helps in the faster and easier configuration of the system. This happens because the requirement for infrastructure is not linked with the application.
- Independent containers: Every container is independent of the other which allows the execution of almost every application. These containers also allow applications to run in an isolated environment.
- Easy setup: Dockers allow easy setup of the system. This saves time on entering codes with less effort and in less time.
- Lower costs: Containers require less hardware as they allow center operators to work into smaller hardware. Hardware sharing, in turn, leads to lower costs.
- Portability: It can run on any platform, including Google Cloud, Amazon ec2, and virtual box among others.
Both Kubernetes and Docker are open cloud-native technologies. Almost all cloud service providers support the components of both Kubernetes and Docker in their managed offerings. Both platforms can be used independently. However, large projects prefer Kubernetes, whereas smaller projects can also function on Docker. While thinking about Kubernetes vs Docker, you must consider your requirements and the functionalities that fulfill your application’s needs.
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