As we know, the world is now running on containerization technology to ease the process of deploying and managing simple to complex applications.
They are very fast, portable, easy to manage and and scalable that any other traditional practices that we used to follow in early days. And, in order to scale or orchestrate our container infrastructure we need some container orchestration tool like Docker Swarm or Kubernetes which help us to manage our containers.
We cannot neglect the fact that Kubernetes is the most widely used container orchestration tool right now. But, Docker Swarm comes with its own benefits.
I think that the container orchestration tool should be chosen depending on the complexity of our application. While Kubernetes is better at managing huge and very complex applications (thousands of deployments), Docker Swarm can be used if we need some lightweight solution and which can run up-to few hundred containers and dozens of nodes.
In this article, I am going to explain why and when to use Docker Swarm over Kubernetes as a container orchestration tool.
Benefits of Docker Swarm over Kubernetes:
Some of the benefits of Docker Swarm over Kubernetes are:
Easy to use:
In Docker Swarm, compose file is used to manage the environment. Hence, it is very easier to manage compose files that Kubernetes manifests.
Easy to setup:
Docker Swarm comes pre-installed with the installation of Docker whereas Kubernetes comes with many ways to install like minikube, kubespray, microk8s and many more.
Less resource usage:
Docker Swarm is best at using very few resource for running a production-grade cluster than Kubernetes.
While swarm is using few hundred MB's to get the master node up and running in smaller clusters, Kubernetes, in other hand has large overhead and needs few GB of RAM free to work.
The administration tooling in Docker Swarm is pretty easy and minimalist (like Portainer) that that of Kubernetes (like Rancher). Portainer can be integrated with Kubernetes as well.
Also, Swarm can also be integrated with Ansible which helps us to easily control our application stacks.
Good networking support:
Docker Swarm comes with very good networking solution with installation whereas in Kubernetes we need to integrated abstracted, third-party and loosely coupled networking solutions.
With Swarm, we can get automatic load balancing with DNS under the hood. But that is not the case with Kubernetes deployments.
However, we can use Nginx Ingress Controller with Kubernetes for load balancing purpose.
Lightweight Kubernetes Solution — K3s
As the main reason for choosing Docker Swarm over Kubernetes is because it is simple and lightweight.
However, Kubernetes too comes with its lightweight solution. Kubernetes K3s eliminates the heavy and complex architecture and provides a lightweight solution to Kubernetes.
K3s is packaged as a single binary (<50MB) that implements the complete Kubernetes API and reduces the dependencies needed to install, run and manage a production Kubernetes cluster.
For Docker Swarm users, who want to switch to Kubernetes but are not sure if they are ready for full-on Kubernetes, K3s could be an ideal alternative to that.
Kubernetes is large and complex to operate and manage. One needs to have an in-depth understanding of the underlying concepts, abstract architecture and resource type usage for different scenarios. This makes learning Kubernetes relatively difficult and more confusing.
In other hand, Docker Swarm is simpler, easier to maintain, more familiar, and quicker to scale services.
We can use any tool for container orchestration depending on our need and complexity of the application. No matter which platform we choose, we will be well-positioned to scale and manage our containerized applications.
But, if we are looking for light-weight, minimalist and quicker container orchestration solution, Docker Swarm is the way.