Kubernetes vs. Swarm: Which Container Orchestrator is Best for You?

Kubernetes and Docker Swarm have both evolved into great clustering and container orchestration tools. But there’s a lot of debate about which one is best for managing your data center and containers. We don’t have the definitive answer, but to help you decide, we offer below a comparison of Kubernetes and Swarm as orchestration platforms.

Here’s a table that compares the major features of Kubernetes and Swarm:

Kubernetes

Swarm

Free and open source?

Yes.

Yes.

Integration with native Docker tools?

No. Because Kubernetes uses third-party tools like etcd for part of its operations, it doesn’t interface directly with Docker tools such as Compose.

Yes. Designed by Docker, Swarm hooks directly into the Docker API. You can use all of Docker’s native tools with it.

Setup process

Fairly involved and varies by platform. That means more configurability, but also more hassle for some DevOps teams. Fortunately, setting up Kubernetes on most common systems is well documented.

Pretty simple. You basically just create a discovery service, then run your Swarm containers. The process is the same on all platforms. Easy, but not necessarily as powerful as Kubernetes.

Container deployment

Usually achieved via Kubernetes’s Deployment tool. It’s straightforward to use – but it’s different from the Docker YAML configurations you know and love if you’ve been using Docker for a while already.

Usually done directly from the Docker CLI or through Docker Compose. That’s great if you’re dealing with Docker containers, but maybe not so great if you don’t want to be locked in to Docker’s toolset.

Networking and persistent data storage

Well supported via flannel and Persistent Volumes.

Before Docker 1.9, not well integrated. More recent Docker releases support flannel and multi-host-networking, and you can use Docker Data Volumes for persistent storage.

You will probably notice two general themes that run throughout that table and differentiate Kubernetes and Swarm. One is ease of use. The other is the level of integration with Docker’s native toolset — as opposed to the software stack used by alternative container platforms, like CoreOS.

Generally speaking, Kubernetes is less simple than Swarm to set up. That reflects the greater power and flexibility you get from Kubernetes. If you like having the ability to use different tools and configure things endlessly, Kubernetes is for you. If, on the other hand, you just want to get your containers up and running quickly and with minimum hassle, Swarm will appeal.

Kubernetes is also less tightly bound to particular toolsets. That makes it different from Swarm, which basically requires users to use Docker’s tools. Here again, if you want to build your data center using a variety of different components, stick with Kubernetes, which lets you use parts of the CoreOS stack alongside elements of Docker’s. But if you are already invested in Docker’s tools and configuration formats, and you are sure you want to stick with them, then stick with Swarm.

Christopher Tozzi

Christopher Tozzi

Christopher Tozzi has covered technology and business news for nearly a decade, specializing in open source, containers, big data, networking and security. He is currently Senior Editor and DevOps Analyst with Fixate.io and Sweetcode.io.

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