Kubernetes vs. Docker – Why You Need Both and Shouldn’t Pit Them Against Each Other

The question of whether to use Kubernetes or Docker is completely misguided. The two technologies do not compete with each other; rather, they complement each other perfectly. Both have their place and specific role in modern infrastructure and DevOps environments. Anyone viewing them as alternatives likely hasn’t worked much with containers or is searching for a quick answer without the necessary context.

In this article, we delve into what Kubernetes and Docker achieve, where their differences lie, and why you should combine both technologies to unlock their full potential.

Docker – The Container Format and Runtime Environment

Docker has established itself as the standard for containerization. It is software that allows applications to be packaged in containers and run across different environments. Docker ensures that the entire software stack of an application—including all dependencies—runs in an isolated container. This means an application always runs the same way, whether locally on a development PC, in a test environment, or in the cloud.

Docker is not only the container format but also the runtime environment that executes the container. The Docker Engine ensures that containers can be run on an underlying infrastructure. This flexibility and portability make Docker the preferred choice for deploying software in modern development and operations environments.

Why Docker is Important: Docker allows applications and their dependencies to be fully isolated, enabling them to run independently of the underlying system. This simplifies both testing and deployment and is particularly crucial when working with microservices, where applications can consist of numerous containers.

Kubernetes – The Container Orchestrator That Makes Operations Possible

Kubernetes is the tool responsible for managing and orchestrating containers. While Docker provides the foundation for creating and running containers, Kubernetes ensures these containers are scaled and managed within a larger infrastructure. Kubernetes handles the deployment, scaling, and management of containers in a cluster, so you don’t have to worry about the details once your container production grows.

Originally developed at Google, Kubernetes is now the de facto standard tool for container orchestration. The platform offers a variety of features specifically designed for managing large, distributed applications. These include automatic scaling, self-healing of applications, and an extensive API that allows easy integration with existing tools.

Why Kubernetes is Important: Kubernetes takes on the tasks necessary for managing a multitude of containers. It ensures containers are highly available, scales them, and restarts them autonomously in case of failures. Without Kubernetes, managing large numbers of containers in a cluster would quickly become confusing and error-prone.

Docker and Kubernetes – The Perfect Combination

The key takeaway for IT architects and DevOps teams is: Docker and Kubernetes belong together. Docker is not “better” or “worse” than Kubernetes, and vice versa. Both technologies complement each other by providing containers with Docker and ensuring these containers are operated in a scalable, highly available, and automated infrastructure with Kubernetes.

Kubernetes requires Docker as a container engine to run the containers it manages. At the same time, Kubernetes can also work with other container engines like rkt or CRI-O, so Docker doesn’t have to be the only choice for Kubernetes. Nevertheless, Docker is the most popular choice for creating containers due to its widespread use and simplicity, which are then orchestrated by Kubernetes.

A typical scenario where Docker and Kubernetes work together might look like this: You have an application consisting of several microservices, and each microservice runs in a Docker container. Kubernetes takes care of the orchestrated deployment of these containers across a large number of servers, ensures they are always available, and automatically scales them up or down depending on load requirements.

Docker Swarm as an Alternative to Kubernetes

Docker Swarm is a simpler, integrated solution for orchestrating Docker containers. It is already part of Docker and allows containers to be managed in a cluster without having to set up an additional platform like Kubernetes. Swarm is a good choice for small to medium-sized applications where the complexity of Kubernetes is not necessary.

Advantages of Docker Swarm: Setting up Swarm is relatively straightforward, especially if you are already familiar with Docker. Swarm comes directly with the Docker Engine and can manage containers across multiple hosts. For smaller workloads or development environments where the full scalability and flexibility of Kubernetes are not needed, Swarm can be a viable alternative.

Disadvantages of Docker Swarm: Swarm has some limitations compared to Kubernetes, particularly in terms of flexibility and extensibility. Kubernetes offers a far greater range of features and is better suited when scalability and resilience requirements increase. In this regard, Swarm lags behind Kubernetes.

Kubernetes – The Comprehensive Solution for Container Orchestration

Kubernetes is the comprehensive platform that goes far beyond what Docker Swarm offers. It provides a variety of features that are crucial in larger and more complex environments:

• Automated Scaling: Kubernetes can automatically adjust the number of containers based on load.

• Self-Healing: If a container fails, Kubernetes ensures it is quickly and automatically restarted to avoid outages.

• Service Discovery and Load Balancing: Kubernetes ensures requests are always routed to the correct container and enables effective load distribution.

• Rollouts and Rollbacks: Kubernetes allows new versions of an application to be rolled out gradually and rolled back easily if necessary.

Kubernetes is particularly suitable for companies running large, distributed applications requiring high availability, scalability, and flexibility. It is the standard when it comes to enterprise-level container orchestration.

Managed Kubernetes by ayedo – Your Solution for Secure Operations

At ayedo, we have been offering tailored container solutions since 2017, helping companies in various industries successfully implement their digital transformation. As experts in operating complex applications, we understand the requirements of modern infrastructure and offer a service-oriented approach tailored to the needs of businesses.

Our Managed Kubernetes service allows you to focus on developing your software while we take care of operations. We handle everything from provisioning to continuous maintenance and scaling of your container environment—securely and efficiently. Our solution is designed for high availability and performance, with a dedicated support team available to assist you at any time.

Whether on the HETZNER Cloud (Public Cloud) or the ayedo Cloud (Private Cloud), our Managed Kubernetes offers you a flexible and scalable solution for your operations. With state-of-the-art security standards (ISO27001) and continuous support, we guarantee that your applications run reliably and performantly.

Our Advantages for You:

• Fully Managed: We take care of the entire operation.

• Always Up-to-Date: Regularly test the latest Kubernetes versions.

• Battle-Tested: Over 60 million users access software in our clusters monthly.

• Secure: We meet the highest security standards.

• Integrated: Works with standard Kubernetes tools.

• Scalable: Adapts flexibly to your needs.

Conclusion – Kubernetes and Docker: An Inseparable Combination

The question “Kubernetes or Docker?” is easy to answer: You need both. Docker provides the containers, and Kubernetes ensures they run reliably on a scalable infrastructure. Both technologies play a crucial role in modern DevOps processes and are not competitive but complement each other perfectly.

Docker for containerization and Kubernetes for orchestration. This is the key to ensuring full flexibility, scalability, and resilience for modern applications. If you want to operate containers efficiently on a large scale, you can’t do without Kubernetes. And you certainly can’t do without Docker.

ayedo supports you every step of the way, from implementation to continuous operation, so you can fully leverage the potential of Docker and Kubernetes.