What's the difference between Kubernetes and Docker?
Docker is a container runtime technology that allows you to build, test, and deploy applications faster than traditional methods. It packages software into standardized units called containers with everything the software needs to run—including libraries, system tools, and code. Kubernetes is a container orchestration tool that allows you to scale your container systems so you can manage, coordinate and schedule containers at a vast scale.
Where are Kubernetes and Docker used?
Kubernetes and Docker are both container technologies. Modern applications are made of microservices—independent components that run each application process as a service. Each service performs a single function and communicates with other services via a well-defined interface called API. Containerization provides the software tool to pack microservices as deployable programs on different platforms.
Create containers
Docker is an open-source container runtime that has gained popularity in recent years. It provides a toolkit for creating containers easily and efficiently. Developers run commands to build a container image file encompassing system libraries, tools, code, and other software configurations that each microservice requires. Every microservice has its own Docker image. You can use the Docker image to run the microservice in any environment.
Manage containers
Most applications are made of several microservices. Some of them can scale to thousands of microservices running across different servers. Multi-container applications introduce new management challenges:
- How should you coordinate multiple containers?
- How should you schedule containers?
- How should you group and catalog containers?
Developers solve these challenges using a container orchestration platform like Kubernetes. Kubernetes is an open-source technology that lets you manage containers at scale. It handles operating complexities so you can scale your workloads and manage container deployment across multiple servers.
Key differences: Kubernetes vs. Docker
Both Kubernetes and Docker are open-source container technologies. However, they are fundamentally different in how they work and what role they play in distributing containerized applications. Developers use Docker to create and manipulate container images. They use Kubernetes to manage multiple microservices at scale. Each microservice is individually made up of multiple containers itself.
Operations
The term Docker actually refers to a set of tools developers use to build, share, and run containerized applications. Here are some Docker commands you can use:
- Use Docker Build to create container images
- Use Docker Compose to define and run multi-container applications
- Use Docker Hub to find and share container images, similar to GitHub for code sharing
On the other hand, Kubernetes works by managing a cluster of compute instances. It schedules containers to run on the cluster based on the available compute resources and the resource requirements of each container. Containers are run in logical groupings called pods, and you can run and scale one or many containers together as a pod. You can automatically start additional pods on your Kubernetes cluster based on their resource requirements.
Core technology
Docker Engine is the component developers use for building and containerizing your applications. It offers APIs which specify interfaces that programs can use to talk to and instruct it.Similarly, Kubernetes control-plane software decides when and where to run container pods, manages traffic routing, and scales your pods based on utilization or other metrics you define.
Biggest benefit
Docker streamlines the development lifecycle by allowing developers to work in standardized environments using local containers which provide your applications and services. It’s container-based platform allows for highly portable workloads. On the other hand, Kubernetes lets you define complex containerized applications and run them at scale across a cluster of servers.
When to use Kubernetes or Docker
Docker and Kubernetes are two different technologies with different use cases. You use Docker Desktop to run, edit and manager container development. You use Kubernetes to run production grade applications at scale.
Summary of differences: Kubernetes vs. Docker Desktop
| Characteristics |
Kubernetes |
Docker |
| What is it? |
Container orchestration tool. |
Stack of container technologies to create and run containers. |
| Use |
Coordinate multiple containers across multiple servers. |
Package applications with libraries and runtime into container images. |
| Main benefit |
Define and run complex containerized applications at scale. |
Standardize application operations and ship code faster. |
How can AWS support your container management requirements?
AWS has several container services that make managing your underlying container infrastructure easier, whether on premises or in the cloud. You can do everything from container orchestration to running containers without managing servers. We give some examples below.
Amazon Elastic Container Service
Amazon Elastic Container Service (Amazon ECS) is a fully managed container orchestration service that makes it easy for you to deploy, manage, and scale containerized applications. You can replace Kubernetes with Amazon ECS to run Docker containers in the AWS Cloud.
Kubernetes vs. Amazon ECS
Amazon ECS provides two solutions in one service—a container orchestration tool and a fully managed service that automatically provisions underlying infrastructure resources. In contrast, Kubernetes requires you to provision resources in the cloud or on premises.
Amazon Elastic Kubernetes Service
Amazon Elastic Kubernetes Service (Amazon EKS) is a managed Kubernetes service to run Kubernetes in the AWS Cloud and on-premises data centers. In the cloud, Amazon EKS automatically manages the availability and scalability of the Kubernetes control plane nodes responsible for scheduling containers, managing application availability, storing cluster data, and other key tasks.
